Hi All -
I'm trying to decide on getting back into speaker design and building , at least for one project. Will be glad to hear opinions from the present day. I'll post my query in Multi-way shortly. Cheers

Hello, long time lurker and have had this account for a while but realize I have never posted in this thread so I haven't been able to message other users 🙂

Hi. What Zout would be prefered for driving 13 meter balanced cables? According to spec they should be ca 1000 pF but I measured them with a DE-5000 to be around 1500 pF. I know zero ohms would be ideal but what would be a realistic figure?

Hi All,
I want to make a First Watt F2 amplifier or, First Watt F2J amplifier, but, I would like to go with the original First Watt circuit, could someone please tell me if, I can still get PCB Boards like these, or similar?

my current system is:
Bgw amplifier performance serie 2-3-4.
Jbl2404,radian 760-jbl2380,tesla arm9408,beyma 15g40.

have a good day and thank you for accepting me into the group!

I want to wind my own SUTs. I know what ratio I want. I know my cartridges impedance and desired loading. What I can not find is how do you calculate the number of turns for either the primary or the secondary? From what I have read I THINK you find out the permability of the core you are using then calculate the inductance you want based on that. And from the inductance you can get the number of turns. Is this right?
Also I can not find out what my target inductance wants to be. Can someone PLEASE help me out here?

I need a 1:2 ratio. My cart puts out 2.7mv the gain of my phono amp is not high enough to use that so I want to get it to 5mv.
The impedance of my cart is 150Ω
Desired loading is 1000Ω

I want an 80% nickel core.

So what is either my primary or secondary turns number?

Jeff

Perfect as new. This Is the original One from Danish Company not the eBay Copy. Stereo 20k used on b1k nutube. Price new 230eur sell at 100eur plus shipping in Europe . Ship costs on request might be 20-30 Eur as i only use insured courier but you can send your carrier to pick It up if you like. Proof It Is genuine can be given of course

I look for a replacement for this 2SC2002 this is what I found let me know what you guys think KSC1008C.

Thank

Hello all - I'm replacing the OPTs on a Chinese PP EL34/KT88 amp, and have been considering Silk and Lundahl, both are mid-tier in terms of price, the Japanese stuff is twice the cost so out of budget range for me. I'm replacing the stock iron, which is ridiculously meek in comparison, and really cheap stuff.
Lundahls are well regarded and there's plenty of stuff written about them but not so for Silk - has anyone used them and can you give me your thoughts/comparisons? For reference, the pair would cost about $450, similar to Lundahl.

March 24, 2023 / Dallas, TX

Miller Audio LLC ( https://milleraudiollc.com/ ) is re-introducing the Dyna-70 Ultimate Upgrade for the Dynaco ST-70 to the DIY audio community. Several years ago Erhard Audio introduced the Dyna-70 Ultimate Upgrade. In our testing and listening trials, we concluded that the Dyna-70 was the best of the ST-70 driver upgrades that are in production and available today. We built and integrated a number of Erhard Audio Dyna-70 Ultimate Upgrades for our ST-70 customers. The Dyna-70 sounds so good the kit sells itself once you hear one.



The Dyna-70 Ultimate Upgrade is different than most ST-70 driver updates offered today because it isn't just an audio driver upgrade, its also a power supply upgrade. In fact, the truth is a Dyna-70 is a more expensive upgrade than just replacing a driver CCA, and it provides the ST-70 something it has always needed- more power and filtering. The Rectifier tube and multi-section cap can have been replaced with on-board, solid-state rectification and a minimum of 2-3X of additional filtering capacitance. It also features an on-board in-rush current limiter (ICL) with a 2-stage warm-up cycle for the signal/preamp tubes to come up before the output tubes, minimizing warm up noise. The Dyna-70 Ultimate Upgrade now comes in two configurations at different price points: Automatic Bias or Manual Bias.

The Dyna-70 Ultimate Upgrade is now available and in production. Visit https://milleraudiollc.com/ for details and contact information. We offer a full selection of NOS 6SN7's, as well as a comprehensive selection of new production EL34 / 6CA7 tubes, and film coupling capacitor upgrades from Mundorf and Solen. We also offer the Dyna-70 bare PCB for DIY'ers in both auto-bias or manual bias configurations, allowing DIY'ers the ability to pick their own parts or experiment with various components.

Miller Audio LLC will be demonstrating the Dyna-70 Ultimate Upgrade at the Lone Star Audio Fest, June 2-4, 2023 in Dallas, TX at the Embassy Suites Hotel, Dallas Galleria,
14021 Noel Road, Dallas, Texas, 75240

For more info on the Lone Star Audio Fest (LSAF) visit: http://lonestaraudiofest.com/

We welcome everyone to stop by and listen to some of the best sounding ST-70's you'll ever hear.

I’ve been down a little rabbit hole. Many good through hole parts have been EOL’d in the recent years and if you weren’t lucky enough to snag some or too late to the party you missed out.

Luckily sometimes you can get by with surface mount equivalents.

SK209 used for SK117

2SC3324 for a low noise high gain similar to 2SC2240

2SC2713 and 2SA1163 being similar to C2240 and A970.

There are some others I have as well, but can’t think of them off the top of my head.

Are there any good large surface mount transistors that would replace or be somewhat near as good for drivers?

Something like 2SC4793 and 2SA1837 or 2SC5171 and 2SA1930 (though I read these last two have poor SOA, so maybe similar specs but better SOA)
Or 2SC4883 and 2SA1859. Any devices that could be soldered to adaptor board and use in through hole designs?

Dan

This is a pair of Tek P6111B probes in excellent, tested condition. Both have ground leads and retractable tips and 2m leads.

Asking $43.50 for both shipped (CONUS only please) if using Paypal G&S, or $42.00 shipped if using F&F.

Thank you.

I posted this in "Solid State", but was hoping to get some input this morning.
A little help, a client has a Goldmund amp that is 20 years old that we disconnected from power and reconnected. Now it goes into protect, and the client is trying to blame us for the failure, but I assume that old caps(?) could be at the bottom of this. Just looking for any insights, thanks!

Clearing out tubes collected while developing a 2A3 amplifier. Also selling the 2A3s in order to purchase JJ 2A3-40.

Two Sets of Factory Matched Electro Harmonix Gold Pin 2A3

• One set in use for about 3 years. Estimate less than 400 hours on these. Run 300V plate to cathode, 60mA. Sound great, no issues whatsoever. Matched at 59mA (see photos).
• $150 set

• The backup pair. Removed from boxes and used once to verify operation. Matched at 63/64mA.
• $200 set

4x 6J5

• NOS Sylvania and RCA metal casing. From VacuumTubes.net. Both low hours. Sound great, no issues.
• $20 per set

2x 5687

• Matched pair. RCA from VacuumTubes.net. Used in a prototype. No issues.
• $20 set

1 pair original spare for consonance phono stage. Asking 55 euro gor the pair

Have one more set of these drivers from the Q150 and thinking of experimenting with a BLH for a sitting room. They can be pretty big need be……36” tall and 10” wide. Depth I’m thinking no more than 18”. As they stand ported in a pretty small box, the Q150 does an f3 around 50hz but that gets the cone pumping………something I’m thinking the BLH can/will help to avoid?

So comment and suggestions please?………seems like a great alternative for a guy who doesn’t care for the beaming effect of full range drivers. Thanks for reading!

Can someone tell me what the output of the Hyper Linear preamplifier is in Voltage as I am in the process of builing one, I would like to power the MoFo Amplifier.

hi,
i have four faitalpro 12fh500 (500rms each, 97dbspl) acting midrange. i need two compression drivers to keep up with my mid drivers.

first i thought i would go for two used gs audio tw-75: https://audio55.se/sv/products/tw-75

but then i thought i maybe should go for something that actually would sound okay, instead of just being very loud (which is what i am aiming for btw)


what are your sugestions on a loud compression driver that can keep up with a pair of 12fh500? i am on a budget

A little help, a client has a Goldmund amp that is 20 years old. We disconnected it from power and reconnected it, now it goes into protect. The client is trying to blame us for the failure, but I assume that old caps(?) could be at the bottom of this. Just looking for any insights, thanks!

So I'm using this dixon 4 channel amp quiet some time now in my daily sound with diy 12v power supply. Today I just put new power on/off switch connected +12v to remote. The amp stays on even remote is switched off via the power switch.

Seems the amp is faulty and I checked with multimeter there is no shot between +12v to rem or to the ground. Anyone knows what to check further. those tiny caps seems fine and no shot detected.

Hi there. I'm going to build a subwoofer and hook it up to an amp that doesn't have low pass built in. I know this has been asked countless times, but could someone point me in the right direction? Would going for a line level low pass or an internal low pass be cheaper or is one better for noise? And is ebay the way to go or could I get better components if I go DIY? Thanks in advance.

rAudio-1 is an Arch Linux-based, active and constantly improved fork of the abandoned audio player project called Runeaudio.

rAudio-1 is available for all Raspberry Pi's:

• 64bit: 4, 3, 2, Zero 2
• 32bit: 2 (BCM2836)
• legacy: 1, Zero

• Metadata Tag Editor (*.cue included)
• Album mode with coverarts
• File mode with thumbnail icons
• Coverarts and bookmarks - add, replace and remove
• WebRadio coverarts - online fetched
• *.jpg, *.png and animated *.gif applicable
• *.wav - album artists and sort tracks
• *.cue - virtually as individual tracks in all modes and user playlists
• VU meter as coverart (for remote screen)
• Live display update across multiple clients
• Wi-Fi connection can be pre-configured for headless mode.
• Access point mode when no router available.
• File sharing
• USB DAC plug ang play
• Easy online update and extra features with addons
• Supported GPIO devices:
  • I²S audio module
  • Character LCD (16x2, 20x4)
  • Power on/off button
  • Relay module
  • Rotary encoder
  • Spectrum OLED (128x64)
  • TFT 3.5" LCD (320x420)
  • VU LED (7 LEDs+Rs)
• Renderers / clients - with metadata and coverarts
  • AirPlay
  • Bluetooth audio (receiver)
  • Snapcast
  • Spotify Connect
  • UPnP
• Streamers
  • Bluetooth audio (sender)
  • HTTP (no metadata)
  • Snapcast (multiroom)
• Support boot from USB drive without SD card
• USB drive
  • Plug and play
  • Audio CD (with metadata and coverarts)
• 10 band graphic equalizer - support custom preset

Latest version of rAudio-1 can always be found at https://github.com/rern/rAudio-1
Discussion and other help available at https://t.me/raspberrypimusic

Some of the functionality can be seen below.

Well, I'm clearing out my remaining tubes.
I have EL84. E80CC, ECC81 and ECC83.

Most tubes are tested with the Roetester and full printouts are available for those tubes.
Some are tested with the "duokit" tubetester.
Some measure in the 100% area and some lower.
Matched pairs available for some tubes.

Send me a message if you are interested in anything.
I'm thinking $40 per tube, ex shipping, but I am open for suggestions.

If someone has some of those Icepower modules with integrated power supply I am also willing to trade.

Shipping is approximate $15 traced insured and half than untraceable and uninsured.

EL84
Philips x4
Telefunken x3

E80CC
Siemens x2
Mullard x6
Phillips x6

ECC83
Siemens x2

ECC81
Sylvania

Hi,

It is not clear in the last Moglia Hybrid Mu follower where is exactly the added gate stopper resistor in his last v8 shematic for the low Fet ?

Is it in serie with the two face to face diodes as the shematic or is it in parrallel with these diodes ?

The blog talks about a shematic error (the R9 resistor) https://www.bartola.co.uk/valves/2019/02/03/hybrid-mu-follower-aka-gyrator-rev08-pcb-update/

Should not it be also 1K ?
?!

Thanks

I am currently using a Rane AC23 to run 2 - 3 way speakers. I am not completely unhappy with the sound but I would like to try something newer. I have read some of the info in the thread about this item But I have questions for those who are using it. I am 71 years old and I cannot solder without burning myself. My hands shake badly and attempts to medicate made me a zombie. Is there any one here that might build what I need for a simple set up? Any idea what it might cost? thanks for your consideration. Please move if I am in wrong area.

I'm new to DIY audio, but I find it fascinating! I think I've been hooked, and caught the bug.

I'm interested in designing, building, and testing speakers and amps, and seeing what kind of testing equipment is available. Waveguide design is also interesting to me.

Hello everyone,

I'm very happy to have recently started my carreer in live sound. I already know a thing or two about speakers and sound obviously but I'm curious to learn everything technical about live events the coming couple of years. My goal is to, when I'm confident in my knowledge and network in the business, build my own custom PA system to then rent out and offer my own live sound services for small to medium scale events/stages at festivals.
The cabinets will be designed with cool looks to stand out and be part of the cosmetics of the stage, instead of like simple black boxes. They will also have a unique party trick up there sleeve that I myself have never seen at any event but I think would be very very cool. This I will keep secret.
Apart of just looking cool the main goal of this system is to produce high-end level sound quality with very wide dispersion but in a PA setting.

My idea for the main speakers:
A line array of direct radiating dome tweeters with a single line array (just on one side of the tweeters, not both sides like most LAs) of direct radiating 5" midranges. I can already hear the PA snobs rushing to their keyboards to tell me that this is stupid and is a waste of amp power compared to just uring compression drivers and waveguides. But these are exactly what I want to avoid for this system because I want to get away from the distortion and coloration that come with them. This line array will be mounted on a as shallow as possible baffle with rounded over edges and maybe even felt or other foam material inbetween and around the drivers to minimize diffraction. Behind this ~90 cm tall line array compartment will be two 15" mid woofers which are horn loaded. The horns sweeps around the back and the sides of the main cabinet and exit out the front. Inspired by the Void Acoustics air array.

The drivers I had in mind:

Tweeters
-8 x SB-Acoustics Satori TW29TXN-B
Or (preferably)
-6 x BlieSMa T34A-4

Midranges
-6 x FaitalPRO 5PR120

Mid-woofers
-2 x FaitalPRO 15FX560

I have experience with both of these brands of tweeters and also when looking at measurments these two are the best (non-beryllium) options on the market IMO. I don't want to use beryllium drivers because of cost and fear of breaking them. Even though these not compression drivers they've got what it takes to keep up with the rest of the drivers and are rather sensitive at 96 dB for the Satori and a whoping 99 dB for the BlieSMa. I would prefer to use the BlieSMa because they have high enough senitivity to be able to play with 6 and because they have the edge on the Satori in terms of distortion, dispersion and transient response. The thing is though that recently all BlieSMa drivers have went out of stock and marked as "end of life" on the website of the Dutch distributor. I'm hoping BlieSMa and the distributor simply broke bonds. It would be a great shame if the best tweeter manufacturer on the planet went bankrupt. Even if this is the case, the Satori is still one of the very best dome tweeters on the market currently.

I compared measurments of a couple of different mid drivers from for example B&C, SB-Audience and FaitalPRO. After comparing the FaitalPRO 6PR160 to the SB-Audience NERO-6MRN150D I came to the conclusion that FaitalPROs mids perform the best overall. The SB-Audience has lower distortion but the FaitalPRO has slightly better dispersion and cleaner decay. However even the 6PR160 doesn't have the dispersion to match very well with the dome tweeter without needing a waveguide at a crossover point that they can handle, so I want to use a 5". The 5PR120 is advertised by FaitalPRO as their flagship 5" mid and looks the most advanced. However I can't find any measurments online. Anybody have an opinion?

For the mid-woofers I choose the FaitalPRO 15FX560. Honestly I din't compare it to any other brands but because I will most likely be using the FaitalPRO mid and it looks like they are one of the best manufacturers of pro woofers so why not just use them for mid bass too. Also having a bigger order of one brand of drivers might have some financial advantages. I simply compared a couple of different models in a sealed enclosure simulation to get rough an idea of the SPL, F3 and transient response of different models. I picked the 15FX560 because it is the most efficient and quickest of their 15" options. It also has the highest F3 but this doesn't matter much because this system will always be accompanied by subs.

Now I will get to my question. How do I get started designing these horns. I know there is a lot of info out the but I got overwhelmed and don't feel like reading the 740 pages of "hornresp". Can you recommend me some pages where I can read a good summary about the principles. And how about modeling software? Maybe some tips?
I quickly found out there are many different types of horns so to save myself some time I would like to hear your opinions on what the best type of horn would be for this mid-bass enclosure. It doesn't have to go very low, a F3 of ~100 Hz would be fine. The main objective for the mid-bass enclosure is quality. Transient speed, tightness and articulation. I know you can do different things with the back chamber of the woofer. How does having a sealed/ported/open back chamber affect the performance. If it does in a similar way to how it does in direct radiating I would go for a sealed back chamber.

Then there will be the subs. I'm still quite indecisive about what driver to use since there's many great options. I was thinking about one of the 18XL models from FaitalPRO, the SB-Audience NERO-21SW1100D or the B&C 21SW152. The main goal for the subwoofers (obviously) is to have best of both worlds with high quality and fast bass while extending very deep. Preferably F3 in the mid 20s. Which driver would you pick and which type of horn?
Now obviously the system will have DSP capabilities. Would it be possible to use a sealed back chamber and boost the lows to get it to go very deep? Or is a ported back chamber mandatory for deep extension?

I am curious to hear what you have to say.

Hello everyone on this forum! I have some questions for some of you that are experienced in speaker modifications and similar stuff.

I have had the passive avantone cla10 (ns10 replicas) for about a year now. I have worked on original ns10's in a few studios, both the Ns-10M and the Ns10-M Studio versions.

I think Avantone did a fairly good job at recreating the ns10 soundwise except for one thing: the avantone tweeter is just plain slightly louder or more sensitive than the ns10 tweeter.
Because of that the avantone cla 10 speaker seems brighter with the high frequency unit being more dominant than on the original ns10's where the speaker sounds darker.
Many reviews seem to state the exact same thing about the avantones.

Just recently i found out that they re-released the new series of the same speakers but now with some cosmetic differences and a "TPC"- 2db tweeter attenuation switch on the back near the binding posts which lowers the volume of the tweeter by 2db, see pics attached.

The question is, how do you think this is achieved? Is it just a simple switchable - 2db L-pad inside the speaker before the tweeter or could it be something else?
I want to integrate the same mod inside my first series avantones, so that i can drop the tweeter 2db. I know that it can be achieved by an l pad but i am wondering if it will change the sound in any negative way or will it affect the crossover? i want to keep the exact same sound just attenuate the tweeter slightly.
The tweeter nominal impedance is stated 8ohms so i have calculated i need a 1.65ohm series and 31ohm parallel resistor to achieve this. Any better ways or anything?
Any advice is welcome! Thanks

The Halo Parasound Amp 21 Amp does not have loop inputs only loop outputs? What does " to the input RCA jack of the right channel? "Right channel of what (the Halo 21 + to ?)"

I'm trying to Set up the input wires for Bi-amping The A 21+ has an RCA Loop Output jack for each channel.

These looping outputs allow the input signal from one channel to be daisy-chained to the other channel’s RCA Input jack. When bi-amping you will connect a standard RCA cable from the loop output of the Left channel to the Input RCA jack of the right channel.

Note: Both amplifiers left and right channel gain controls should be set at the same position.

Thank you

I have a Counterpoint solid state power amplifier which I have been using since a year with my B&W 805 matrix speakers. This morning I changed my preamp to a Schiit Valhalla 2 Tube preamp and everything played well as usual. When I turned on my system this evening, both speakers were whining like a burglar alarm and I immediately switched off the power amp to be safe. There was a burning smell from the power amp for sure like some thing went wrong and the power amp has a 6 Amp 3Ag fuse for each channel next to the banana terminals. Upon observing, one fuse of the left channel had blown.

Tried to borrow a new power amp from a friend, only to find out that the LF/Mid drivers of both speakers are not working. The tweeters are working fine. Is it even possible for an amp which has a fuse at the output, still blow the speakers?


The speaker LF crossover has only 2 parts, a 2mH coil and a 6uF capacitor.

This thread has been split from here - https://www.diyaudio.com/community/threads/beast-with-1000-jfets-redux.364186/

I played with the idea in sim, and ended up with a design using all mosfets, not a jfet in sight. It uses a "fake SIT " pair at the output, using an IRF510, , a ZVP3306A, and a couple of resistors to mimic the triode-ish behavior of a SIT. I drive the SIT with a ring-of two current source using a small signal PNP and an IRF9510. There's my favorite depletion mode mosfet at the input, the Infineon BSS159, and I close the loop from the output to the BSS159 source. Distortion sims at about 0.05%, mostly 2nd harmonic, and gain is about 10X., about the right gain for a headphone amp. I may grab a pair of Audio Technica studio headphones, as they look to sit more comfortably on the ear than the Grados I currently own.

I have a pair of 2017 Sony VFET PCBs and the critical components, 2 pairs of matched SONY VFETs, input jfets, and the 2sk2013/2sj313. The IRF240/9240 are NOT included but they should be easy to find. FYI The VFETS are from Switzerland (brennwa) and cost a pretty penny!
If you always wanted to build this amp this is your chance. PM if interested.

RIP JOCKO

Pat DiGiacomo; AKA Jocko Homo, has passed away.

Still trying to find out details.

He will be missed.

I am selling a set of woofers, tweeters and crossovers to build a pair of Zaph ZBM4 Bargain Mini speakers.
You can find the project here: ZBM4 - Zaph|Audio 4" Bargain Mini.
The woofers and drivers are the ones specified in the project. The crossover's PCB was designed and built using the parts suggested by the designer.
The crossovers were tested connected to the corresponding drivers using alligator probes. The drivers have never been soldered.
The price is US$110 for the set including Priority Mail shipping in the USA. Payment via Zelle. I have 2 sets available.

I thought I saw somewhere an article going in depth on wiring audio output transformers with associated math and layering of windings and such. Does anybody have any idea where that can be found? I've searched high and low....

Hi, im building an amplifier power supply, in my case a dc to dc converter that takes 24v dc and outputs +/-60vdc. It works on the basic push pull converter topology.


My converter has gone great so far but i need to upgrade the transformer so that it can handle higher current. This will be done by increasing windings/ wire gauge, while retaining primary:secondary turns ratio of my current transformer. In order to add more turns, a larger core is needed, which is why i am not using the current core.
Looking into easily available toroid cores in the uk, mostly on eBay, i see alot of fair-rite cores.
I believe i need a core with a high permeability in the 2000-3000nH range, preferably with a diameter somewhere less than 45mm.
The 77 material range looks good?
Any opinions on the 5977002701 core? It is the one I'm thinking of going with.
Would love other core suggestions that are easily available in uk.

Hey there. Its been a while since I had this silly idea: What do you think about using PCB slot sockets for tube amp builds?



This PCB slot sockets idea was used by Sansui, for instance in the AU999.


I like PCBs but dont like to mount tube sockets on them as they tend to get loose over time or break solder pads.
Perhaps one could have tube sockets mounted on chassis and wire each tube electrode to the slot socket and then have the PCB with main circuit connected to that slot socket.

Heater connection can still be outside the PCB.
Of course pcb design and layout is important here, for instance to have grid stoppers resistors as closely to the grid as possible.

Hello,

this Autum I´ll renew my analog setup. The attached Preamp will be one Part of the new Setup. What do you mean? Will it work?

Best regards
Dieter

Chiaki and Bunpei have made a prototype of �gMicroSD Memory Card Transport�h. (In the picutre below, you can look at just black margin of the memory card under the PCB board in right hand. Some colored cablings are for I2S signals.)

http://www.chiaki.cc/Timpy/images/70-i2s2.jpg
Our tiny MicroSD Memory Card Transport plays 16bit/48KHz WAV files stored on a MicroSD Memory Card (MicroSD in short) and outputs 16bit/48KHz I2S signals to a DAC device. The sound produced by the system is very clear, detailed and natural taste of �gpure-audio�h quality in spite of its low cost for materials and we are much satisfied with the result.
We believe that a jitter is very little and data processed here are almost bit-perfect though we have not confirmed them by any measurements.
In the transport, a microcontroller of 8bit 8051 architecture, C8051F316 12MHz, with specially developed firmware reads a WAV file on a MicroSD and sends the data to VLSI VS1053b codec chip.
http://www.vlsi.fi/en/products/vs1053.html
VS1053b codec converts the PCM data into I2S signals based on 12.288MHz system clock generated by TXCO, Fox XPRESSO Crystal Oscillator.
http://www.foxonline.com/pdfs/FXO_HC73.pdf
In our case, the I2S output is directly connected to Wolfson WM8741 Evaluation Board.
http://www.wolfsonmicro.com/products/WM8741EV1M/
The reason why we chosen this DAC is the evaluation board provides easy pin headers for a direct I2S input

http://www.chiaki.cc/Timpy/images/70-wm8741a.jpg
and the board is easily available from an online shop with a reasonable price.
http://www.profusionplc.com/pro/gex/pcatdtl0?ipartno=WM8741GEDS-V

Bunpei proposed the basic idea of connecting the VS1053b I2S output to the WM8741 evaluation board and Chiaki prepared the actual VS1053b-based hardware and the 8051 software by modifying his own prototypes. Bunpei owes this successful implementation to Chiaki�fs state of art crafting technique for both hardware and software accumulated through his own Timpy (Tiny MP3 Player) projects using VS10xx series and 8051.
http://www.chiaki.cc/Timpy/index.htm ( In Japanese )

The current prototype has a limitation for WAV file quality. It accepts 16bit/48KHz only. We therefore convert a 16bit/44.1KHz WAV file into 48KHz in PC and copy the file into MicroSD media through USB.

For sale 6 pcs Speaker SB Acoustics SB34NRX75-16.

Price €130/piece + postage. €700 for all 6 pieces.

Only used for a test - approx. 30 hours. Excellent driver for OB speakers.

Unfortunately, my room is too small for them.

Original packaging. Location Europe

Hi everyone, i’m hoping some one has the patience to point me in the right direction to repairing this fairly expensive boston acoustic msub

first the off/on/auto switch was busted so i forced it into auto mode by bridging a connection on the main board and now the blue light comes on but i don't get any audio output. Does anyone one have any experience repairing this amplifier or even a schematic? I believe this unit is very similar to the boston acoustic HPS10, HPS12 highout subs. There’s a few schematics of the HPS floating around but the preamp section is blurry and i can’t read alot
of it so maybe some one has a better quality one? I looked it over, checked some the mosfets, some of the power resistors and cleaned that nasty conductive epoxy glue stuff off but not having much luck in the trouble shooting department. The mosfets are heating up the heat sink to a normal temperature when i try to play a song so im leaning towards and issue with the preamp section

I did however find a part of the PCB that was discolored from heat that may be an area of interest. It consists of two transistors which you can see in the short videos i attached along with some pictures to my google drive.

As i was investigating the issue i notice some resistors and capacitors appear to be missing from the preamp board but it’s hard to tell if they broke off or if they were intentionally left off (see attached pic)
C263
R238
C259
R282



Boston MSUB board photos

Hello, ive got a nice little amp that needs a ~500w dual rail supply ( has a -60v output, a 0v “virtual ground” output, and a +60v output)

Does anyone know of a relatively simple circuit to take my 12v and split it to a 60v, 0v, 60v output? preferably with soft startup and control feedback? have a milling machine, so can etch pcbs pretty well.
I have seen a few designs that use the tl494 that look good, however im not very confident with transformers so it really handy if you recommend a transformer with said schematic (or, i dont mind winding one)

[solved]

Hi i am new to the forum, so hello to all.

I have ended up here as i am working on the CSR8670, i am trying to use the extental SPI flash on the CSR8670 and i am having problems. I was wondering if anyone had any experience using it ?

So the issue i am having is while the SPI flash is connected to the CSR8670, when i run the nvscmd.exe to identify the external SPI it gives me the manufacturer ID and the size of the flash but when i go to erase it in order to be able to write a partition table to the flash it gives me an error saying it can not erase the chip.

The only information i have found so far is that the CE pin of the SPI flash could not be connected or not being pulled low which isnt the case as ive checked it. Or the syntax of the command is incorrect which it is not.

So i am at a bit of a loss as to why it recognises it but will not delete or erase the flash.

Any advise would be much appreciated

I generally play digital audio from my computer via my EMU 1212M sound card. I prefer hi res, I've ripped a lot of my LPs @ 192k/24 bit, and I buy hi res down loads from HDTracks and ProStudioMasters (unfortunately I can't buy from the Pono store in Australia). I have also ripped my hi res DVDs and Blu Rays to hard disc. Recently my audio buddy has been ripping all of our SACDs with his PS3 and I also now have a collection of DSD tracks. Software is Foobar, and I use the sacd plug in to play DSD files. Sound is pretty good, not as good as my turntable but hi res beats the pants off red book.

Anyway you will know that Foobar converts DSD to PCM before it sends it to the sound card. Then recently I read that Delta Sigma DACs (including the CS4398 which is on the EMU sound card) convert PCM to single bit during conversion. So, when playing DSD files, FooBar converts bitstream DSD to PCM, then the sound card converts PCM back to bit stream. Wow, there has got to be a better way. So I started investigating USB DACs and my eye was captured by the DIYINHK USB receiver and Sabre DAC combo. Very reasonably priced if it all works!

ES9018K2M XMOS DSD DXD 384kHz USB DAC with Bit-perfect volume control and SPDIF input - DIYINHK

I received these components (very quick delivery from HK) and am very impressed with the build quality. As I was going through the admittedly sparse documentation I noted that the output pins on the USB board were putting out native DSD signal, left and right, on 2 of the pins. Then something that I read on Joe Rasmussen's site many many years ago came floating to the top of my mind - I recall he was talking about Sony SACD players, and that he was able to play SACD simply by finding the DSD signal on the Sony's circuit board and filtering it (3rd order at 90kHz IIRC) before a j-fet buffer sent the signal to his pre-amp. No DAC at all!! Well isn't this the way to go? Send the DSD files from my hard drive out through the USB and pick off the DSD from the USB board?

So far I have achieved partial but very promising success. I have connected my PC to the USB board, and set up FooBar as per instructions. And it plays! I am a minimalist designer, and I eschew buffering and any electronics whereever possible (especially op amps) and right now I am taking the DSD output off the USB board (single ended) to a pair of Lundahl LL1527XL trannies. Theses are configured 1+1:1+1. The balanced output from the transformers goes straight to my balanced attenuator which sits right atop my balanced power amps. I am relying on the transformers to filter the high feq DSD noise, and I have added a zobel across the secondary (15nF, 1kohm) as suggested by Joe Rasmussen in a thread about Sabre DACs and transformers. So I am not even using the DAC board.

How is the sound? A mixed bag. Highly transparent. I have never heard such extended treble from digital. And the sound is almost a 3D analog presentation - every instrument has its own space on the sound stage. Even the best digital has been 2D before (through my sound card or Cary multi-player). But the bass is a bit light. I need more inductance in my transformers. The LL1527 is rated at 10Hz with a 800 ohm source, so I am guessing that the output impedance of the USB board is several kohm. And of course the level is down. The USB board has a 3.3V supply, and as its single ended it will only be putting out 1.1V RMS at full output. My power amp (DIY) was designed for regular 2V input, so I can't get full output. And as this is still prototype, I am using a cheap 5V SMPS with a 3.3V LM3940 regulator - this is way too noisy.

So i need to do something about the bass and output level. There are 2 options spring to mind.
1. Build a jfet gain stage (2 x gain). This would be a LTP with the input on side grounded, and the LL1527XL across the drains of the jfets. And a resistor across the drains to knock down the gain to the right level (also reduces output impedance which gives better matching for the transformer).
2. buy a 1:2 transformer with enough primary inductance to provide full bass response. Note - I did try the LL1527 configured as 1:2, but this reduces the primary inductance - and as expected, bass just about disappears. Has anybody got a recommendation for a 1:2 transformer, capable of 2 v output, which as as transparent as the Lundahl but with more primary inductance? I imagine something like a 5kohm:20kohm transformer is required.

Regarding all my PCM files - the foobar sacd plug in will convert PCM to DSD on the fly. I am playing PCM files in this manner, ie convert them to DSD128 and play as above through the USB receiver. Only one small wrinkle - this works perfectly with 44.1k files (including 88.2k and 176.4k) but doesn't work with 48k files (including 96k and 192k). The work around I have implemented is to use the Foobar DSP re-sample function to resample all PCM files to 176.4k. This then converts nicely to DSD that will play through the USB board. Has anybody else come across this, and is there a better way to play 192k files?

So I really believe that this is the way to go. The best DAC is no DAC!!! There is more to be done, but the prototype is only one day old. I am sure that I can improve it given a bit more time. Any suggestions would be welcome.

UPDATE 10 September 2015.
I now have this working as described in later pages. My final solution is as follows:
Hardware. I have replaced the DIYINHK USB board with the board from JLSounds. The advantage is, I can run the JLSounds at DSD256 in Linux without a driver (in Windows, and Linux, DoP is limited to DSD128). See final circuit in post #335
http://www.diyaudio.com/forums/digital-line-level/273474-best-dac-no-dac-34.html#post4446944
Software. I bought a licence for HQPlayer Windows and Linux. In Windows 10, I convert everything (PCM and DSD) to DSD128 and send to the DAC board. Sounds excellent. In Linux I convert everything to DSD256. Does it sound better? Not that I can tell, but I can do it, so why not 🙂
Note - when using HQPlayer v3.7, the CPU load was 55% when upsampling to DSD256 and I was getting intermittent glitching. HQPlayer 3.8.1 was recently released, it seems to be more efficient and CPU load is rediuced to 42% when upsampling to DSD256, and no glitching.

Hello, I thought I'd run my ideas passed you guys. Its pretty simple and straight forward but I find this concept interesting for a simple low power amplifier and the way its efficiency is boosted.
Standing current is set to 910mA, So the output transistors are dissipating a toasty 13W each.

Distortion is just shy of 0.01% at 12Vp-p, but mostly all 2nd and 3rd.

I have attached the asc LTspice file for anyone interested. Its simply a experiment at this point, but would like to know if its worth working on.
Thanks 🙂

Rotel RC-1070 Preamp with MM Phono Stage​

I have a good condition fully functional Rotel RC-1070 Preamp with MM phono stage

It has a few tiny marks on the top cover but other than that it is in very good cosmetic condition.

$309 USD with FREE Shipping to US & Canada

​

​

hello from robert sweden

SOLD


Just done up today, one set of complete and tested Miro AD1862 DAC + JLSounds i2sOverUSB stack.
In my opinion, this is the most direct and best combo for the gem, AD1862.
Sounds wonderful. It is a full, completed DAC, a pair of NE5534 op amp is included on board the IV stage.
Play with your own op amp to choose your flavor after that, although i can say that the NE5534 is an enjoyable result.

You need +5/-5V and +12/-12V directly to the DAC board. The JLSounds board's 'dirty side' is configured to be powered by the USB Bus ie. drawing +5V from your USB source. This can be changed to be powered from a PSU of your choice if you wish. Can be done very easily by cutting a pcb track under the JLSounds board as instructed by the user guide, and then soldering two wires from pads available on the DAC board out to the PSU. The XO and reclock circuit of the JLSounds is drawing +5V (digital supply) from the DAC board when you stacked and isolation from the USB 'dirty side' is achieved. Very neat and clean design.

Case it up with transformers, PSU, connectors and you are ready to rock and roll.
If you are wondering why I am selling this gem - I think some members here are aware that i usually buy enough parts to do up a few boards.
All parts used are bought brand new, including the AD1862 chips, for the purpose of putting up the DAC. All caps are high quality ones including Nichicon gold, Elna Tonerex, Panasonic FM etc


I am asking USD$300 for this DAC , and i will cover the worldwide registered shipping with tracking available.
I am only ready to accept Paypal Family and Friends as payment.
I have shipped 52 packages to US, UK , asia and Europe, not a single glitch so far.

More information of this DAC here :
https://www.diyaudio.com/community/threads/dac-ad1862-almost-tht-i2s-input-nos-r-2r.354078/
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-128#post-6836256

Anyone else run into this problem? The speaker connector on my Parasound A 21+ Amp is locked up, won't turn right or left.

Thank you

Hello i have been play music for a while especial diy speaker.

Hello, here is what I am looking for, confused with too many choices.
A all around general purpose, low power, low cost MOS, FET, CMOS, MOSFET.
Requirement is:
Trought hole package.
Able to sink 4 mA ( say at least 10mA for safety margin )
Off/On for gate <= 0 volt / gate > few volts.
To drive an Led.

Pretty much like an open drain CMOS logic inverter.

Only 13 years after registration, it's time to introduce myself.
Interested in electronics, computers, tech "and stuff" since the 70s (when I was a kid), I lately returned to electronics and more precisely audio.
Currently running a 1210, Denon DVD-A1XV and AVC-A11XV.
However I lately purchased a Pass Aleph X clone and a XONO clone (both "used", but of incredible build quality), so heading for a DIY preamp and eventually an external DAC for a secondary system.

Hi,
I'm deciding between building a stereo single supply LM1875 or using a pre-made TPA3255 board. I'll be using a linear 34V 3A power supply and I think the LM is more suitable to my liking (was using 3116 board before and much prefer 3886).
I searched this and other forums, and most are referring to datasheet (https://www.ti.com/lit/ds/symlink/lm1875.pdf) with few variation in input (1u vs 2.2u) and output (2200u vs 4700u) coupling caps, and feedback resistor values. Some add additional filtering power supply cap. No other significant changes. I need PCB layout that include only amp and not the power supply, so I think I'll using perf board instead. Here's the diagram from datasheet.



My question is;
1. I planned to use 4700uF for output cap but not sure about input cap so I'm keeping it at 1uF.
2. For layout, based on stability suggestion on 3886, I should keep R5, R6 and C4, C7 close to the chip? Is it applicable for 1875?
3. What wattage rating should I use for R7 in Zobel network?
4. Will perf board give me problems? (assume good soldering)
5. Is there any more suggest changes or adjustment? Thiele network? I'm not using lower impedance speakers, mostly around 4-8 ohms (I heard that 1875 does not like 4 ohm).

Thanks for suggestion,
AP

Does anyone read introductions? if you do, hi there. I am here to help troubleshoot a logitech z5500 hack (or at least share my experience with it).

May end up getting wrapped up in other things whilst here... seems to be some interesting folk about.

Cheers

Optimum Crossover

I have developed what I believe is an exceptional audio crossover. I have tested it theoretically using the circuit analysis program Nova-686. The frequency response is perfectly flat from 20 to 20 kHz.

I am inclined to believe that this may be the best possible passive, three-way crossover. However, I am open to feedback and would appreciate it if someone could review it and provide his opinion.


Crossover Characteristics

1. Flat frequency response. +/- 0.01 dB, 20 Hz to 20 kHz.
2. The input impedance is a constant at 8 Ohms
3. Good square wave response..
4. Group delay, 670 usec max.
5. Consists of only four capacitors and four inductors. (no resistors).

Crossover Frequencies

The frequencies chosen serve as a good starting point for the DIY builder.

20 Hz to 350 Hz.
350 Hz to 3500 Hz
3500 Hz to 20 kHz


Physical Limitations

Moving from the theoretical to the practical presents some challenges.

Audio drivers do not exhibit ideal impedances. This leads to non-flat frequency responses. However, Zobel networks can be employed to address this discrepancy.

It is difficult to go from a theoretical design to one using standard parts. However, this design achieves optimum performance using standard part values.






Schematic “Best Possible Passive Crossover”
(3-way 2nd order)




PS (The mid driver must be phase inverted.)

L1 = 5.0 mH C1 = 39 uF
L2 = 5.0 mH C2 = 39 uF
L3 = 0.5 mH C3 = 3.9 uF
L4 = 0.5 mH C4 = 3.9 uF








Frequency Response






Copyright 2024
Robert Stanton

Hey guys, I hope this topic has not yet been discussed in that way.
I am interested in how to choose the right Op-Amp for specific circuits, like:

• Unity gain buffer (non-inverting)
• Summing amplifier (inverting)
• Filters (i.e. Linkwitz-Riley, Butterworth etc.)
• Phono preamps
• Headphone amps

I wonder in which circuits it is beneficial to use a Bipolar, JFET or CMOS input Op-Amp
As I understand some things are just down to personal preference, but I would like to understand the technical background behind the decision.
So which specifications are taken into account?

• Gain bandwidth product
• Slew rate
• Input noise
• Offset voltage
• Input bias current
• Common-mode rejection ratio
• Input impedance
• Open loop gain
• Output current
• Capacitive load drive

The goal for me is minimal distortion and noise.
Happy to hear about your decision process 🙂

For my next project I already collected a Horn (TAD TH4001 clone) and driver (18sound nd4015be).
Idea is to pick a 15" midwoofer for 30-600/700Hz). Music only, no HT subwoofer necessary.
Living room 5/6 m, want to hear loud and clean.
Closed Box of between 80-150L would be my idea, active driven by Hypex FA252.
I am not willing to pay 1700€ for the TAD 1601/1603. Quite old design, there should be more modern options available?
(dont push me on that statement🙂
Not convinced about the JBL 2216 either for going up to 600/700 Hz.
The only comparable low MMS(86gr) low FS(26Hz) 15" I could find was the scanspeak 38WE. Price insane (1700€ as well), I dont buy the eliptical voicecoil idea too much.
But do I need an FS of 26Hz?
My alternative candidate if not would be 18sound 15NTlw3500. FS of 45Hz, MMS 106gr with a Bl of 19,5. Looks like nobody here ever used that one?
Simulating both in basta I get almost the same bass extension for the 38WE in 85L and the 18sound in 100L, both with a Q just above 0,5.
Any experience with one of these 2? I want to avoid building test cases and develop something from scratch...Of course I have checked the usual recommendations like Faital 15PR400, not convinced it would make me happy forever...
thx
Wolf

Good morning everyone!

Recently, somebody (don’t remember who this was, ZM, Ben Mah or another great Man) wrote that an AVC (Autoformer Volume Controller) should not be measured by the resistance with a DMM.

Why?

I know Klipsh owns them and the Jamo info I found there has no contact info anywhere and no dealers listed. Are they gone?

I was just wondering why most horns / waveguides used with compression drivers are very deep with narrow directivity? I'm not talking about pro use, but rather in a domestic application.

Would a shallow waveguide like we see used with direct radiators not provide fewer response irregularities and wider dispersion while still having enough SPL capability?

Do the phase plugs inside the compression drivers not couple well to shallow waveguides?

This isolator is based on adum4166，It can be used on USB 2.0 audio，Support to dsd1024.

I received two GA77RVT in trade and want to restore them. Today I discover that they are very different from each other.

One is a Crestline version with 8 tubes and 9 pots, for which I have found a schematic.
Other is ? version with 9 tubes and 11 pots, for which I need help to find a schematic.

Sorry about the out of focus picture.

Thank you. Mark

I'm wiring a 500ASP + 500A stereo power amp. Just wondering if the onboard fuse in the 500ASP is sufficient or if it is better practice to add another fuse inline right after the power switch. Many thanks for any advice.

I am selling "Trafokernspulen" from Mundorf you can see more details here. 449 Euro. Shipping is extra.

https://www.kleinanzeigen.de/s-anzeige/mundorf-2-trafokernspulen-35mh-0-3ohm/2772583582-172-4688



In my other advertisements online are Mauhorn V "5" enclosures, aluminized Fostex FE208 sigma and so on

Fully assembled and tested boards for the CNC phono pre (audiokarma fame). Preamp and dual supply psu. No transformer.
Currently running 5532 opamp but can be substituted with several other options.
Asking $90 $80 shipped (in usa).

Hi everyone

I just thought I would start a thread to be sure to keep my thread-titel! More will follow. The long story of my Le Grand MEH Danois starts in post #5.

I did share some ideas about my MEH´s here, the short version:

https://www.diyaudio.com/community/threads/synergy-horn-questions.407369/post-7559570

Happy new year to everyone.

Steffen

SOLD!!


Offering a pair of New in the Box single ended audio output transformers. Complete with original documentation and metal “Tango” plates. One transformer was removed, but left in its plastic wrap, for photo. These are the top of the line original Hirata Tango transformers with Permalloy Core. 45% Nickel Primary. Virtually unobtainable now.

Asking $2500. Buyer to pay all shipping costs.


Specs:
Impedance Primary 3.5 K Ohms
Secondary 0-4-8-16 Ohms
Power 15 Watts (30Hz)
Frequency Response 20Hz-45Hz (-2dB, 4v, rp=zp, Ib=90mA)
Primary Inductance Min. 23H (1mW), Max 30H (50Hz, Ib=90A)
Max DC current 200mA Loss 0.41dB (16 Ohms)
Primary DC Resistance 115 Ohms
Dimensions W110mm D110mm H114mm Weight 4.5 kg
Color Hammer Tone Grey

I've got a pair of Turbosound TS-8sw400A8 drivers from a defunct pair of Turbosound Inspire iP500 speakers.

Any idea what the specs are for the driver?

I looked online and could not find specs.

Hi all,
Anybody has the schematics for this kind amp. Going into protection for no reason. Disabling the protection amp coming and playing normal. Shorting the optocoupler 3 and 4 pins makes the amp on. Thank you

I see a lot of nice designs discussed here. I am looking to get back into speaker building I abandoned years ago. I want my first project to be a full range driver in an enclosure I can use at my desk.

Recommendations on driver/box suitable would be appreciated. I will be driving g themwithahomebuilt 6BM8 tube amp with very low power,but great sound.

TIA
Roger

I've written a simple python program, in a git er done brute force and ignorance manner, which indicates where frequency collisions occur in a cabinet given the width, height, and depth (in millimeters). I'll post below. The idea is that each dimension has harmonic frequencies, when one or both of the other dimensions have similar harmonic frequencies then that frequency is prone to nulls (or possibly boost). The program identifies these collisions and there is a very simple optimizer that looks at changing dimensions to reduce the number of collisions.

Example exec: py ./main.py 208 968 363
208 is width in mm, 968 height, 363 depth


Looking for feedback on logic/calculation errors. Thanks.

import sys

# Copyright 2023,2024 Aaron Loyd
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


def dimensionHarmonics(dimension):
harmonics = []
# speed of sound in mms 342900
hfirst = round(((342900 / int(dimension)) / 2))
harmonics.append(hfirst)
for harmonic in range(2, 10):
harmonics.append(hfirst * harmonic)
# for value in wharmonics:
# print(value)
return (harmonics)


def swcalc(wharmonics, hharmonics, dharmonics):
whcollisions = []
wdcollisions = []
hdcollisions = []
for windex in range(9):
# diffval = 0.05 * wharmonics[windex]
diffval = 50
for hindex in range(9):
if ((abs(int(wharmonics[windex]) - int(hharmonics[hindex]))) < diffval):
whcollisions.append(str(wharmonics[windex]) + " with " + str(hharmonics[hindex]))
if ((abs(int(wharmonics[windex]) - int(dharmonics[hindex]))) < diffval):
wdcollisions.append(str(wharmonics[windex]) + " with " + str(dharmonics[hindex]))

for hindex in range(9):
# diffval = 0.05 * int(hharmonics[hindex])
diffval = 50
for dindex in range(9):
if ((abs(int(hharmonics[hindex]) - int(dharmonics[dindex]))) < diffval):
hdcollisions.append(str(hharmonics[hindex]) + " with " + str(dharmonics[dindex]))

return whcollisions, wdcollisions, hdcollisions


def printCollisions(whcollisions, wdcollisions, hdcollisions):
print("----------------------------------------------------------------------\n\n")
print("Width Collisions with Height")
if (len(whcollisions) <= 0):
print("none")
else:
for whc in whcollisions:
print(whc)

print("----------------------------------------------------------------------")
print("Width Collisions with Depth")

if (len(wdcollisions) <= 0):
print("none")
else:
for wdc in wdcollisions:
print(wdc)

print("----------------------------------------------------------------------")
print("Height Collisions with Depth")

if (len(hdcollisions) <= 0):
print("none")
else:
for hdc in hdcollisions:
print(hdc)

print("----------------------------------------------------------------------\n\n")


def checkCollisions(owidth, oheight, odepth, totalCollisionCount):
owharmonics = dimensionHarmonics(owidth)
ohharmonics = dimensionHarmonics(oheight)
odharmonics = dimensionHarmonics(odepth)

owhcollisions, owdcollisions, ohdcollisions = swcalc(owharmonics, ohharmonics, odharmonics)
collisionCount = len(owhcollisions) + len(owdcollisions) + len(ohdcollisions)
if (collisionCount < totalCollisionCount):
print("\nusing width of " + (str(owidth)))
print("using height of " + (str(oheight)))
print("using depth of " + (str(odepth)))
print("collision count is " + str(collisionCount) + " instead of " + str(totalCollisionCount))
print("\n")
printCollisions(owdcollisions, owdcollisions, ohdcollisions)


def optimize(width, height, depth, totalCollisionCount) :
print("----------------------------------")
print("optimizing")
origvolume = width * height * depth
maxvolume = origvolume * 1.02
minvolume = origvolume * 0.98

# width check
print("\nexpand width")
volume = origvolume
owidth = width
oheight = height
odepth = depth

while (volume < maxvolume):
print(".", end='')
owidth += 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

print("\nshrink width")
volume = origvolume
owidth = width
oheight = height
odepth = depth

while (volume > minvolume):
print(".", end='')
owidth -= 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

# height check
print("\nexpand height")
volume = origvolume
owidth = width
oheight = height
odepth = depth
while (volume < maxvolume):
print(".", end='')
oheight += 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

print("\nshrink height")
volume = origvolume
owidth = width
oheight = height
odepth = depth

while (volume > minvolume):
print(".", end='')
oheight -= 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

# depth check
print("\nexpand depth")
volume = origvolume
owidth = width
oheight = height
odepth = depth
while (volume < maxvolume):
print(".", end='')
odepth += 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

print("\nshrink depth")
volume = origvolume
owidth = width
oheight = height
odepth = depth

while (volume > minvolume):
print(".", end='')
odepth -= 1.0

volume = owidth * oheight * odepth

checkCollisions(owidth, oheight, odepth, totalCollisionCount)

print("\noptimizing finished.")


if name == 'main':
print("Collisions can occur at the following frequencies:")
print("Width\t\t\tHeight\t\t\t\tDepth")

# dimensions in millimeters
width = float(sys.argv[1])
height = float(sys.argv[2])
depth = float(sys.argv[3])

wharmonics = dimensionHarmonics(width)
hharmonics = dimensionHarmonics(height)
dharmonics = dimensionHarmonics(depth)

for index in range(9):
print(str(wharmonics[index]) + "\t\t\t\t" + str(hharmonics[index]) + "\t\t\t\t" + str(dharmonics[index]))

whcollisions, wdcollisions, hdcollisions = swcalc(wharmonics, hharmonics, dharmonics)
printCollisions(whcollisions, wdcollisions, hdcollisions)

totalCollisionCount = len(whcollisions) + len(wdcollisions) + len(hdcollisions)

print("total collisions = " + str(totalCollisionCount))
print("----------------------------------")

totalWidthCollision = len(whcollisions) + len(wdcollisions)
print("total width collisions = " + str(totalWidthCollision))

totalHeightCollision = len(whcollisions) + len(hdcollisions)
print("total height collisions = " + str(totalHeightCollision))

totalDepthCollision = len(wdcollisions) + len(hdcollisions)
print("total depth collisions = " + str(totalDepthCollision))

if (totalCollisionCount > 0):
optimize(width, height, depth, totalCollisionCount)

I got two pairs of 4-Ohm woofers: ADS S10. I’m planning for their wiring configuration. The only way I could think is to wire them in series to make the impedance to about 8 Ohms. However, I realize that connecting woofers in series have no advantages. But it’s not recommended to wire them in parallel as well since the impedance would be too low; 2 Ohms. So, what should be done to these woofers? Are there any creative ways to implement? I mean using series crossover network with the woofers connected in parallel, or vice versa.

Hi all!

Summary:
Looking for advice on a kitchen music only system please, specifically, which driver size, model and choice of enclosure as laid out below. Also a sanity check on what I am doing generally please. Especially regarding 4 ohm drivers, choice of amp, room acoustics and treatment, positioning etc, likely power. Also bearing in mind the awkward positioning and potential use of 8 inch drivers limiting extension, should I be considering a port, or is that just asking for trouble?

Current set up

We have recently had some kitchen work done, and I have now been able to add some cable and speakers to the tops of the cabinets in the kitchen, to support two existing speakers in the adjoining open plan dining room.

The current set up is Wiim Pro to Echo Link (for the built in sub crossover which lets me high pass the mains so they are not trying to produce so much bass that they stop sounding lively) to 2x stereo amps to 4x JBL control one speakers. Due to aesthetics, they are not set up in stereo imaging configuration with space between them, but paired at opposite corners of the kitchen- dining room, facing each other quite high up. Each of the two corners has a left and right speaker.

It actually sounds pretty good for some tracks, but the high pass is set quite high for these speakers at 100hz, as they are especially weak below this point, -10db at 80hz with a port. I like a really punchy sound with lots of power around 60-100hz, so I'd like to do something different.

Space and budget are in short supply unfortunately, so I am hoping I can just add one, two or three subwoofers to provide for the low end. I have a spare pair of Monitor Audio Bronze bx1 bookshelf speakers which sound much better than the Control 1s to my ears, so I might try to get an extra pair and use them instead of the smaller JBL speakers, but for now they cannot go into the system as the tweeters clash tonally with the JBLs.

I can conceivably add up to three subwoofers to the system, but can probably only have time and money capacity for one over the next few weeks. There is waf space for the following:

1. Dining room sub

On a bookshelf under the bookshelf speakers. Room for a 20 to 40 litre enclosure with up to 10 inch driver.

2. Kitchen sub position #1

Behind a wine rack on top of the kitchen cupboard. Roughly equal distance between both sets of speakers, but located in a corner, behind a breeze block and plasterboard cupboard wall.
Room for one or perhaps two 8 inch drivers in a standard cuboid, rectangular shape at approximately 1.25 litres, not including driver volume or bracing. Potentially room for a decent size port with one driver.
Or, room for a wedge shaped enclosure, with a larger 10 inch driver on the slope so it fits in the space.

3. Kitchen sub position #2

in between the kitchen's JBL control one speakers but probably unsightly if they are eventually upgraded to something bigger like the bx1s: 0.5 litre box, up to 8 inch driver
Given the smaller drivers and awkward placement, with potential for interaction with kitchen cabinets/shelving, I was planning on sealed subs as opposed to ported.
The measurements allow for an inch or so of isolation slate and foam /rubber/blue tack underneath the subs, so as to reduce interaction with the cabinets.

Amp
I picked up an extra Fosi Za3 in the recent prime day sales. I was planning to use this with a 4 ohm driver or driver's where it will hopefully be able to push 160w on two channels at 4ohms, up to 200w peak, or 200w single channel with up to 300w peak. It is able to drive 2ohms apparently, but how reliably and for how long, I don't know.

I'd like to use the Fosi or even two of them of necessary, as I am using the same for the mains, it was only around £110, it's small, and it will work with 12v triggers from the Wiim pro. But if it will be too underpowered, I can return it, and look to buy a used power amp like the Crown 1502 for example.

Room size
Kitchen size is 5x3mx2.2m, and adjoining dining room is 4.5x3.5x 2.5m. It's all open plan.

Room corrections/goal
It's a room with many hard surfaces. I built three double-size sound absorbers a couple of years ago to improve things. Two are 2 inches deep, and one is three inches deep. 45kg/m density iirc. The kitchen section is still very hard and echoes somewhat. I could add a massive ~ 6 inch+ bass trap behind the wine rack if I don't put the sub there. Perhaps a small one AND a sub if I keep it square shaped and 8" driver as opposed to wedge/10". I could also add small absorbers behind the speakers if that would be worth the effort?

I plan to use the custom 10 band dsp in the Wiim Pro to tame any awful peaks and echos. I am also not averse to cutting out most of the signal below 40 or even 60 hz if necessary.
Ideally, I'd like tight, punchy bass up to around 88db at 3m, nearly flat to 30hz. But 40hz would be okay too, especially if 30hz is somewhat audible.

Woodwork
I enjoy wood work but am only a novice/at best intermediate, I have power tools including router and would aim to make any visible enclosures look something like this🙁 using MDF painted to match the kitchen, and a routed oak glue-up piece to decorate the baffle). House of Marley Get Together Duo Bluetooth Bookshelf Speakers Black - Sustainably Crafted, Wireless Turntable Speaker, Mains Powered / 25 Hours Battery Life, Aux in, High Definition Bluetooth Speaker https://amzn.eu/d/0cZsxv8l

The one behind the wine rack though would potentially be a basic box, which is frankly appealing, as I could build it very quickly and get some bass in the room without worrying about appearances.

Drivers and qtc
I've been looking at Focal flax range of drivers. They're quite pricey, but model nicely in winisd. I'd be interested in anything cheaper that can still get me a decent qtc in the size enclosures available to me, and preferably those that can be powered by my Fosi Za3, so probably 4ohms or 8ohm x2 in parallel for a 4 ohm load, if I've understood that correctly.
I am aiming for a qtc of 0.7 or below. I am used to a big subwoofer in our main room, which is a 4.5 cubic feet Eminence lab 12c tuned to 27hz. Without a port, it has a qtc around 0.5 or 0.6 I think.

Thanks for your advice!

As I now know that I prefer my valve/hybrid pre this is up for grabs.

I have replaced the power supply caps , some tantalum caps and a couple of resistors.
one rca/phono socket was broken off when I got this so I’ve now replaced several as they were an awful tapered type.

This is surprisingly heavy and given its rarity its for collection only ( Buckinghamshire ) I may post/ship at a push.

MM/MC
There is a switch on the side which Ipresume is for different cartridges ( 1mv and 5mv ) this is factory standard.
I have no means to test the apparently very good phono stage .

The lettering has worn away around the volume knob.

£450

For sale top pair of prestige range Seas coaxial drivers

Seas Excel 5" Coaxial driver​

SEAS Excel C16N001/F - E0051-04/06-6 5" Magnesium Cone Coaxial Woofer​

Driver are like new in original packing(used in hobby hifi project CORONA).If someone will build this project I also have Scanspeak revelator passive radiator pair.The Corona is some truly hiend speaker for little till mid rooms.Im now building some verry big speakers,thats why I sell this.If someone interested plese contact me.Price would be 300 euro pair!!Scanspeak passive radiator pair 150 euro.I also have parts for crossover if someone interestedThis top sounding drivers are used by Progresive audio Extrem series loudspeakers!!

I'd just buy a Dynaco or similar, but they're out of the budget for this application. I have a few transformers and a pile of vac tubes plus some other parts, but it seems to me by the time I buy a chassis and the missing filler parts, I'll easily be at what a decent Chinese amp kit costs. There's a Class AB push pull amp there on Ebay for $219 complete with everything, ready to solder together. Just seems like it's the way to go in the interests of time sourcing/scrounging all the parts. Any thoughts on this as a good home music amp?

https://www.ebay.com/itm/133481896420

all of a sudden, "line-in" is not being recognised by software such as audacity, diligent waveforms etc.
i thought i must have blown the inputs, but things are ok if i run win7
i have checked audio settings / uninstalled re-install drivers
i think its maybe due to the last win10 update???

So this project has been going on for quite a while now.
Mostly because time related issues.

Anyway, It all started with the complete frustration that there are basically two things:

• no affordable/cheap alternatives for active filters
• the analog active filter boards that are available never make ANY sense (in my opinion).

Having the full flexibility of something like a DSP is all nice, but often projects simply just don't need all these options.
Yet, at the same time amplifiers seem to be cheap and easily available.
At the same time, there doesn't seem to be anything that could just basically replace a passive filter.
Also, a DSP with good THD+N and SNR can be very expensive.

So I started with this idea in mind what a general and generic (passive) filter would look like.
Basically any filter needs at least:

- shelving filter to compensate for baffle step

• 1st, 2nd or 3rd order HP filter for the tweeter (can also be any other kind of driver obviously 🙂 )
• A simple parametric EQ for this channel (boosting as well as cutting)
• Gain/attenuation

as well as;

• 1st, 2nd or 3rd order LP filter for a woofer (again, can be something else)
• Also a simple parametric EQ (boosting as well as cutting)
• maybe also gain, just because why not. (technically not needed)

Also helpful in any active filter system, is a addition 1st or 2nd order HP filter to be able to cross with something like a subwoofer (or low end woofer in a 3-way system).

So with background in such designs and a bit of puzzling, I also managed to make this very versatile to be able to connect or bypass certain sections (filter blocks) or even daisy chain all of the above for even more flexibility.

To make that a bit more visual, here is a block diagram with a couple of ideas;


As well as a schematic;


So basically this will work in a 2-way system or for something like a single system when all functions are needed (like a subwoofer).
With a bit of creativity, other filters or tweaks can be made. 🙂
A Linkwitz-Transform isn't quite possible yet, but I am a bit on the edge of just making a little adapter board for that instead.
(it kinda messes up the nice PCB design)

The param EQ is adapted a little bit to just make the design and calculations a bit easier.
(yet still working the same)

- The first stage can also be used as a (very) crude differential (balanced) to single ended amplifier.

- Any HP filter can be replaced for a LP filter or vice versa (just by swapping the capacitors for resistors and resistors for capacitors)
This way a 4th order LP (or HP ) filter can be made (see variation 2)

- In some cases phase can be flipped, which can be very simply fixed, by flipping the polarity of the speaker/driver itself again.

- opamps can be any flavor/price/performance (as long as they are unity gain stable)

PCB size for now 83.5x40mm
incl volt regulators, as well as some SMD parts on the back like bridge rectifier, decoupling etc.




Inspiration was taken from;

https://www.linkwitzlab.com/filters.htm
http://sim.okawa-denshi.jp/en/Fkeisan.htm
https://sound-au.com/articles/active-filters.htm

(and probably a lot more, I forget what I have gathered over the years 😀 😀 )

Here are my questions towards the new 3-way speaker project of mine.

1) I’m looking for the dome midrange drivers that could work well under 600Hz. The desired corner frequency (-3dB point) for the high-pass section of these midranges is intended to employ at 550Hz with approximately 12dB/octave natural roll-off slope. And it will be combined with the 12dB/octave electrical slope to make the acoustical slope to be 24dB/octave. In brief, I’d like to use these mid-domes in place of the 4” cone midranges in my design.

What qualifications are required for that requirement, i.e., Fs shouldn't be lower than … Hz, Re should be in the range of … Ohms, etc.?

2) If the low frequency drive units used with those mid-domes are, of course, responsible for below 550Hz, would it be better or acceptable to use the subwoofer drive units instead of the traditional woofers for the low frequency section?