Good Afternoon everyone. I am looking at getting the Mini Dsp Hd unit to help me with my crossover building and hear what it will sound like? I don't want to spend all this time guessing and buying parts for the 2 way speakers to sound like crap. I have the amps and the pre amps and the cores and drivers and microphone. All I need now is the mini dsp hd. I will be using the Dayton omni Mic v2. which was a gift to me. I was wondering if its worth it $205.00 dollars for the Hd or the reg. Mini Dsp.I do have a dayton audio that goes from my computer dsp to RCA Right and Left plug in.. I have everything but, this unit. I also have a corner spot that has all the acoustic padding to make it dead quite. I wanted to use it to redo my dads two way speakers? I just really don't want to spend any more money then I have to. So what do you guys think? Jeff

I recently picked up one of these, mildly moded by the PO. The pre sounds wonderful throughout the mids, very 3d. But the line section seems a little wimpy on bass. The phono section sounds just fine compared to other good phono sections.

I think the only mod that the PO did was to substitute 1 microfarad Mundorf caps for the C9/C109 ooutput coupling caps that should be 3.3uF per the schematic.

Wondering if I should put some 3.3uF caps back in? Line stage tubes are Amperex bugle boy 6DJ8s, those should be good. I could roll in some other tubes, or maybe test them on my Eico?

Would appreciate any input.

I'm going to build a Totem Model 1 clone and I wonder if anyone has a diagram of the crossover.

I got the drivers pretty cheaply. Dynaudio 15W75-4 and Seas 25 TA/WGB-TO. Does anyone have the T/S for these drivers? I haven't had any luck searching online.

I'm new to crossover design so I'm going to design my own then compare to the original design. Any help appreciated.

For sale 2 pairs of 2SK60/2SJ18 all in the same T-54 rank.
Used but in clean shape and perfect working condition, come from the vintage Sony amplifier.
V-Fet's 4 pieces = one set= price 200 € + shipping.
Two set's available. Payement with PayPal.
Thanks for your interest and best regards

Now that I've got my Pass Aleph 4 and Pass P1.7 working fully I notice that my Arcam AVR280 has some sibilance on the FM. I use it us my tuner.

Has anyone any suggestions ?

Maybe mods to the Arcam or a better tuner.

I'm using a roof top aerial.

I have some motor noise. It is very light, and when I put felt pads under the 4 screws (the levelling ones, the chassis stands on them on my workbench which obviously amplifies the sounds) it does not seem any louder while on the bench than when lifted with hands. But there is the noise. Not humming type, more like dry rustle.
How much, if any, is allowed?

The motor was cleaned and lubricated, without taking the bushings out. The motor when stopped rotates for another 12 seconds or so.
Also what's important is, after the power is down, the motor spins absolutely silently.
When the platter is on (this ensures the motor will be running at the same speed for a while after the power is off) it still goes silent the moment it is off.

Hi. Part of the Estate sale, a nice, well reviewed Network Player, ROON Ready, the SOtM sMS-200. I have a complete set with AC adapter, original box and instructions sheet. Sell around 450U$, asking 350U$ + shipping + 3% Paypal fee

Thanks for looking
SB

Can anyone recommend the best 3 or 4 way DIY or kits for under $2,500? I'm thinking ~$2,000 for drivers and xo (passive or dsp) and the remaining for carpentry, etc (I have a retired carpenter on hand). Since I went to high school in the 80's, I mostly listen to classic rock and vocals. No rap, metal or classical music. This will be my 2nd home DIY (recent - Seas paper cones - seems more matched for classical music), and I also have experience with auto installs from my college days. I'm considering the Selah Ottavos and the LX521, but I'm not sure if the LX would be a good match for my musical taste. Also considering the Statements II. 😕Thanks, J

Looking to sell a couple of board sets.

1. XRKAudio ABBB (Alpha Big Boy with Buttah) PCB set. Price: SOLD.
   
2. OPC The Wire NTD1 Classic V4 PCB with PSU PCB. Price: SOLD.
   
3. Sjostrom Audio SSR03 PCB. 2 PCBs available. Price: SOLD.

Today I was trying to get the REW beta impedance measurement to work. It didn't, but the frequency response measurement worked fine with an impedance rig, and I could even see cone resonances on the waterfall plot, so I decided to try an old idea I had.

To be clear, I am using the frequency response measurement in REW to plot the voltage across a speaker as it is driven by an amplifier through a 39k resistor. This is not the acoustic response, but it does show damping of the dustcap resonance.

Yellow is stock and green is with the tape. The 9KHz resonance is due to something else changing between measurements, probably having to do with the rear motor vent.

This is an old Radioshack 40-1033 midwoofer, which would seem like an ideal test case due to it's squashed shape dustcap.

Before and after waterfall plots clearly show a resonance at 2.4KHz is suppressed by the tape. The tape has to be in the center and the shape of the hump as pictured is optimal. It is fairly sensitive to the shape. The hump is about 9mm wide and 7mm tall.

The tape is Scotch 35 red PVC electrical tape. It is thicker than generic electrical tape and you can tell when handling it why it might work well in this case. It is very damped and tapping the roll of tape has a very dead sound.

Simply putting a piece of tape on the dustcap has the opposite effect, the resonance moves down in frequency and gets worse. So I think the hump is acting like a mass damper.

I'm looking for an inexpensive, simple sine wave generator for visual inspection of waveforms at audio frequencies. New, my choices appear to be a $12 DIY kit, or a $30 unit with unwieldy button controls. Or I could get this B&K for about $50 shipped. Assuming it works, this is a no-brainer, right?

Up for sale: I have three pairs of brand-new-in-box Mark Audio (Markaudio) CHBW-70 wideband drive units. I mentioned these in my natural colour cone CHP sale thread here: FS Mark Audio (Markaudio) CHP-70 Gen.2 drive units (natural cone) FS Mark Audio (Markaudio) CHP-70 Gen.2 drive units (natural cone)

A special 4in wideband driver developed at the same time as the CHP-70 Gen.2, with its own coil, suspension & slightly thicker cone with a focus on lower frequency load handling & midrange performance, so it can handle compact midbass duties. This is one of Markaudio's rarest main production units; to the best of my knowledge only a single batch was produced although it can be put back into series production if desired. Most went to OEMs. General response is similar to the CHP-70 Gen.2 with a little less on the top end & enhanced load capacity, with the same semi vintage / natural tone of its CHP sister model. Good for partnering with tweeters; planar units like HiVi's RT1C-A or Monacor's RBT-95 series were popular choices along with domes.

Main CHBW-70 features:
-Usual Markaudio shallow-profile cone for consistent off-axis response
-Reinforced self-damping polymer basket
-Long-throw suspension
-Well balanced Fs, Qt, Vas to suit different types of load (works well in sealed, vented, horn & QW -example below as wideband midbass drivers in a pair of compact floorstanders)
-Black (charcoal colour) paper cone
-Suspension, coil & cone designed for lower & midrange frequency performance
-Supplied with factory gaskets and connecting hardware

I'm asking £30 per pair plus shipping (less than half original retail)

All drivers are packaged in their original Markaudio boxes. I use sustainable FSC rated outer cardboard boxes fastened with heavy-duty packing tape. These are reinforced inside with recycled heavy-duty cardboard and packed with recycled brown / grey packing paper and high quality bubble-insulation.

hi- just got the above- mint condition- plays well on original adapter- but very warm-any one know if this is normal?

Hi,

I want to show you a speaker project of mine, called the Cyburgs-Needle. It is designed to be a nice newbie project, it is very easy to build and also quite cheap. But it is also nice as second loudspeaker pair in the bedroom or wherever. It uses a single Visaton FRS 8, the costs for one pair should be under 30 Euro.
Although the maximum sound pressure with an 8 cm driver is naturally somewhat limited, there is no compromise in the performance, they sound really neutral over the whole bandwith. In a typical room application 50 Hz and lower is no problem. You'll be amazed 🙂
If you have any questions or suggestions, just send an E-Mail.

Nice greetings from Austria, Berndt

Here a picture of the final prototype before finishing.

I'm curious about different dispersion characteristics typical effect on the overall sound of the speaker in-room.

Say you have a 3-way with wide dispersion all the way up to the top octave like this:



And compare that to a 2-way with more narrow but even dispersion pattern like this:



Obviously the 3-way radiates more treble energy into the room compared to the controlled directivity 2-way.
How does this manifest in perceived tonal balance of the speaker?

ESS 12" passive radiators $100+shipping

Amplifier HQQF-55-506_5_1 finalized

Hi all. Im involved in a beach bar/ lido project. As well as an overall venue system for lower level general use, they want a semi portable system for beach parties and outdoor cinema use.

Their supplier has proposed a pair of cheapish active 12 inch cabs with bluetooth, so i suspect they dont have quite the same image as me of what we need!


Since i am busy, but wish to make my mark on the system, i would propose they provide a decent pair of circa 600w 15 inch active cabs, then i come up with a supporting subwoofer system myself.

Im a fan of tapped horns having built 4 based on a volvotreter design a decade or so ago.

So, going in that direction, i have a few questions:

First, would i be better off with, say, a single 18, or a pair of 15"s? I imagine maybe the 18 would be cheaper, an easier build and set up, but a pain to shift

2x15s would have benefit of being a pair of sources, more flexible, easier to move, but more expensive and time consuming to build, and more fiddly to set up and put away.

Also, given the outdoor location, and neighbours to the property, maybe even 3x12" in a cardioid arrangement?



Im looking for punchy deep bass, something mobile enough to tip back onto wheels and drag indoors each night, and easy to set up in a few locations around the (flat but lawn and sand) site.


I did read somewhere about a sub with a smaller rear - firing driver on a delay, giving cardioid response in a single cabinet. Cant find it now.

A tapped horn with this feature would be nice, but i guess if the rear driver needs a seperate cabinet it would end up a very bulky speaker.

Looking forward to any suggestions!

Hello

Looking at the possibility to use the Seas W12CY003 as the midrange. Thinking about using a 6,4 litre-ish sealed cabinet for it. However I've seen some other mid range drivers with acoustic vents. Would there been a benefit to use a acoustic vent on the Seas? And would it affect the enclosure size?

Hello there

I need to replace the coil with a ferrite core with air core, due the distortion in high volumes.
The value of inductor is 4.7mH. Because of the high price I decided to try winding my own coil. I have checked fewer online calculators, but all they give a completely different results.

Here are three attached screenshots
the first one is taken from Shevano website
the second one from Tesla institute
the third one from Coil32

I kept the same former size and induction in the all of the simulators.
I don't have LCR meter and I'm unable to check the wonded coils.

Would you recommend some good and reliable calculator, which is closest to the measured results? I think 5% deviation is OK in my case.

Thank you in advance

Regards
Georgi

It's a real beginner's DIY project so i don't want or need anything that is priced more than £50. They'll be running off of a Hypex DS1.2 plate amp

Has to be available in the U.K - no U.S stores please.

Any suggestions?

I have a Garrard 401 that I cannot get to hold a steady speed. Even after 30 minutes warm-up, the speed will vary +/- 0.01 RPM on each rotation. I am measuring with an accurate tachometer that does not average.

The main bearing has been cleaned and polished, and oiled properly. The platter rotates smoothly and rundown is over 30 seconds. The motor has been disassembled and the bearings replaced. It spins freely.

I know that these tables do have some inconsistency but it seems that this one is too variable.

The only thing I can think of is that there might be some problem with the motor windings. I will appreciate any suggestions. Thank you.

Hi guys, been a while (thankfully? lol)


A friend of mine is trying to figure out a strange issue that's going on with his JTM45 clone by mojotone (schematic link below). He bought it pre-built online, second-hand. I've linked to an audio file which he provided, the problem definitely disappears with lower tones being played.



Here's his take:

Right away I noticed some prominent, not so nice harmonics/overtones on certain notes. They become noticeable with the volume around half, and present themselves more as I turn up the volume from there. I've attached a short clip (volume at 10) demonstrating what I mean. The higher notes at the beginning are the ones with the stronger overtones. As I come back down the neck, the overtones (to my ears) disappear. Also, I only really notice it if I'm doing single note stuff, which could still be problematic if I'm getting a G# overtone ruining my E-minor solo.


I've asked him to run the amp head removed from the cabinet to rule out sympathetic vibrations, no go. Lastly, when it comes to odd noises my first go-to is swapping out the tubes, as I've found them to have the highest likelihood of microphonics. Also no go. The company has written to him and mentioned lead-dress as the major factor for 'ghost notes' - but as far as I can tell (photo attached), this amp was built by someone with a fair bit of experience.



I'm stumped. I'm now suspecting those carbon-comp resistors but I feel that's grasping at straws. Hopefully someone knows what this is all about...



Audio file link


Schematic link


Thanks!

Hello, i'm searching schematics for zapco z300c2 and orion 2150SX

thank you

Hi,

A thread to know how to implement : volume control, filter, casing, shielding, powersupply, etc for the discrete R2R DAC made by Soekris:

Feel free to ask and answer. Regards, Eldam
*********************
Original Vendor thread (DAM 1021) http://www.diyaudio.com/forums/vendors-bazaar/259488-reference-dac-module-discrete-r-2r-sign-magnitude-24-bit-384-khz.html

OEM (DAM 1121) Building thread: Building with the Soekris dam1121

Currently available files for dam1021 (updates): Soekris Engineering ApS, Downloads

For a quick drawing with connections and more detailed descriptions + tweaks, : The Soekris R-2R DAC: Technical Details | H i F i D U I N O

Diyaudio WIKI : Soekris R2R DAC - diyAudio (usefull links, more to come)

Parts: some usefull parts ref and inputs given by members (thank you) :
PS traffos
62020 - 2x7AC 5VA - http://www.digikey.com/product-detai...108-ND/3881389
62030 - 2x7AC 7VA - http://www.digikey.com/product-detai...059-ND/3881371
2x7AC 10VA 70040K Talema Group LLC | 1295-1040-ND | DigiKey
2x7AC 7VA - MCFM70/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 7VA | element14 Australia
2x7AC 5VA - MCFM50/07 - MULTICOMP - TRANSFORMER, TOROIDAL, 2 X 7V, 5VA | element14 Australia
Netherlands : Toroidal transformers for 115V and 230V applications
France:transformateur torique 15va 2x7v
The links are to the Australian website but it's easy enough to change location using "Change Country" at the top right of the page. The 2x7AC 5VA is also available from a UK based seller on eBay (more than 10 in stock) MCFM50 07 Multicomp Mini Toroidal 5VA 2X 7V | eBay
US: AN-0107 - 10VA 7V Transformer - AnTek Products Corp good price !

For alternative DC feeding possibility, some informations below & elswhere in the original thread: some mention noticeable difference. A simple torroid is a good enough starting point.

Pulse transformers if input Spidf (SE) choosed (Soekris's input post 41): PE-65612NL Pulse Electronics Corporation | 553-1580-5-ND | DigiKey or better (?) S22083 Newava Technology Inc | 470-1003-ND | DigiKey ; DA101C - MURATA POWER SOLUTIONS - TRANSFORMER, 1:1, 0.01H - 0.0206H, DIL | element14 Australia. Notice here than the first PE would have the best inter-windding capacitance which is the interisting point for chosing it- Dac itself has a the best jitter rejection possible due to the fifo, so jitter perf of the others pulse transformer do not matter with this DAC, so quietest noise is prefered over the best jitter perf for the input pulse transformer! Abraxalito input : read the thread)

SPIDF (AES) : Audio Note or Tribute traffos (sorry no cheaper refs yet 🙂 ! but here surely sota noise rejection... cobalt core, etc)
TOSLINK: Toshiba RX modules advised for good quality: TORX177 for 5V and TORX147 for 3.3V

Connection shematics for the SPIDF; http://www.diyaudio.com/forums/vend...magnitude-24-bit-384-khz-111.html#post4202602

Volume control (if the pot way is choosed) : "Any mono linear one from 1K to 10K, preferable high quality conductive plastic to avoid noise" (so just one mono linear pot control the two chanels) http://www.diyaudio.com/forums/digi...ris-s-dac-implementations-17.html#post4194108 : I.E. : 3851A-282-103BL - BOURNS - POT, COND PLASTIC, 10KOHM, 20%, 1W | element14 Australia or P231-QC20BR10K - BI TECHNOLOGIES / TT ELECTRONICS - POTENTIOMETRE POUR PANNEAU 10K | Farnell France

DIY H.Q connectors (to avoid shorts) J3 : 2-87456-1 - TE CONNECTIVITY / AMP - WIRE-BOARD CONNECTOR RECEPTICLE 26 POSITION, 2.54MM | element14 Australia ; J10 : 1-87499-7 - TE CONNECTIVITY / AMP - CRIMP HOUSING, 1 ROW, 10WAY | element14 Australia or :
Inputs & front panel switch board GB (for USB Amareno+ SPIDF): Input and switch boards for Soekris DAM1021 DAC

USB to Serie RS232 interface to update the DAC via a laptop: 1 Port RS232 USB to Serial Adapter - US-101 - Brainboxes - RS422/485 RS232 Serial Cards , Digitus USB auf Seriell DB9 Adapter schwarz: Amazon.de: Computer & Zubehör (PLL throughpass chip inside) / USB-to-Serial Converter - UC232A, ATEN USB Converters ;Trendnet - Convertisseur USB vers Série, TU-S9: Amazon.fr: Informatique etc ! (take care with the compatibility with W 7/8 when you buy one)

Debuging your USB to Serie interface DimDim member blog : R2R | Dimdim's Blog

Working Thread about the Digital filter improvementof the FGPA chip: http://www.diyaudio.com/forums/digital-line-level/269776-filter-brewing-soekris-r2r.html#post4224106

Output-stage Thtread: http://www.diyaudio.com/forums/digital-line-level/270014-output-stage-soekris-r2r.html#post4228899

Mother board control kit: http://www.diyaudio.com/forums/vend...soekris-dam1021-1121-control.html#post5071729

Hi,

First time poster so bear with me please.

Decided to purchase a random cheap power amp to play around with after purchasing a tube Buffer/Pre amp.

Didn't really know about the whole DIY thing till after the purchase, which lead me down this rabbit hole..

New Finished TDA7293 Stereo Amplifier 100W Class AB HIFI Big Power AMP|power amp|amplifier 100wstereo amplifier - AliExpress

That"s the amp i purchased. Hasn't arrived yet so kinda looking forward to it.

Wanting people's opinion on the layout and design/performance when compared to my current main amp- Yamaha AX490.

I've just sorta grasped what a bridge rectifier is and through my readings has lead me to believe the design isn't very well implemented?

I have no real electronics knowledge but have done some minor tinkering in that department. Really curious on the topic at the moment.

I would like to build Frank's Ultimate Preamp using the 6sn7 tubes, but it would have too much gain. In researching this site, I found a thread started by Merlin el Mago: https://www.diyaudio.com/forums/tubes-valves/227387-lundahl-ll1660-opt-franks-6sn7-linestage.html
With the help of Thomas Mayer, he came up with the attached circuit for a headphone amp.

In trying to spec the output transformer, Thomas told him to double the plate current if the two tubes were in parallel and not double it if the tubes were in series. It is not clear to me what the current through the transformer will be. Mago posited that it would be 8ma, but I am not sure.

Could someone point out how to calculate the current through the transformer? Also, any thoughts on whether this circuit would be a good one for getting lower gain out of a 6sn7 would be appreciated.

By the way, I would like between 6 and 12 db or so for my line stage.

Thanks for any help anyone can give me.
Jazzzman

Hi,

Could you please suggest how to approach to solve the issue of "getting low voice / dialog volume and high back ground volume" from TV.
Getting similar issue when i am watching movies from USB drive connected to TV or from laptop connected to TV via HDMI cable.
Most of the time need to adjust the volume with remote when dialogs starts in a movie, and reduce it once background music is on.

Currently building an amplifier. So looking to fix this problem also with this external amplifier.
Do we need to go for:
1. tone controls (bass/treble controls)
2. analog filters
3. dsp based option.
or any other way to fix this problem.

I have a preamp/poweramp combo. The 702 is a 100W stereo power amp MOSFET pushpull unit. It works great and is in very good cosmetic condition. The 602 is fully discrete complimentary push pull bipolar preamp with MM and MC inputs. I would love to sell the pair as a set for $800+ just to keep the family together. Or, I'll sell them separately for $495+.








I can also send the service manual containing the schematics . I will take Pay Pal and ship to the registered address ONLY. Shipping is the actual rate, insured, with adult signature required. PM for any additional details.

I got this organ for free and would like to know if I can make a good audio amp out of this thing, it has the 606913 tube transformers . Please look at the pics and help me work it out

The forum just had some downtime, we're now back up, it is being investigated.

Pearl hum, I bought already built. Any advise where to try to reduce hum. First I thought it was Grado ref sonota 1, there known to hum so tried MI Soundsmith did same thing. Strange thing it changes when you bring tonearm towards spindle at beginning of record it's louder in right speaker. Go towards spindle hum fades louder to left speaker. Sounds like a non shielded cartridge having problems with motor but both cartridges do it. They have never done that on other preamps. It increases with volume. It's not bad at low volumes. Looks like ground mounted on Back for turntable ground is maybe not grounded in the best place will try that first. Are there some common places to look for hum, thanks for any direction.

I haven't been able to find any impressions of this little subwoofer driver. I'm looking at it to build a small 22 litre sub for music only down to around 35Hz to carry the lower half octave or so. I've used plenty of SB Acoustics mid woofers but not any of their woofers. In the past I have used a Vifa M22WR for this purpose and it excelled with music.

I don't need it for HT as I have a Peerless 830452 that's great for that use but it's so so on music.

Hi
Until about 2 - 3 Years back I was able to Order Dale Resistors almost any kind I wanted.

Before that until 1992 there where Resista Resistors from Germany if I remember right. Then there was the announcement that Resista would stop to produce Resistors and the the company would be sold to Vishay..



After that Resista dissapered as well as the resistors.

10 Days ago I ordered Resistors using FARNELL Distributor. There were no DALE anymore.. ONLY Mulitcomp.! When I got them a few days back, half of them were RESISTA.. I don't get that anymore.

I would like to buy DALE RESISTORS, cmf55Series. Does anyone of you know some place to buy them?


Thanks in advance..
Chris

Does anyone know when Onkyo started making non portable players that played CDs or (burned) MP3s. I've got a TEAC CD-1260 that will play MP3s but I think I got ripped off on that. The quality just isn't there. Thanks ... Best 2 ya 🙂

Hello all,
looking for help from someone who has a lot of experience in designing reverb drive circuits. I found many variations of the classic TL072/74 circuits. I decided to take one and modify it for my purpose. I got it up and running. Reverberation works fine! However as soon as i increase the wet/dry pot (R4), i get horrible 60hz hum!
The signals from U1A and U1d are fine, and clean. but when the tank circuit is introduced into the mix, the hum happens. I have put bypass caps all over the place! the spec for the IC states to use .1uf as close to the power pins. Which I did.

So what could be wrong here?
see my attached schematic.

Hi, I’m looking for info for the 11V5501-4 (9909008) 10” woofer, also know as the Focal 27F.
I’m wondering if I can use them in sealed 8cf. boxes and knowing the upper limit might help too.
Thanks for looking

I've been meaning to start a thread on mono vinyl playback for a while, but delay projects meant a lack of anything concrete to discuss. Still nothing concrete, but as a couple of members mentioned it would be useful to have somewhere to discuss this here we go.



I've got a fairly modest collection of mono vinyl (under 100 LPs) and I know that others have a lot more. I am saying this as the amount of effort to expend is related to the size of the collection. Having been collecting little bits an pieces for a couple of years, for my first semi-serious foray into mono playback I had an old ortofon MC10 converted by rotating the coils 45 degrees, making right channel lateral and left vertical. I had a good reason for this which I will explain another time but so far it works well. So I'll use this as the reference point to beat by other methods as time allows. Prior to this I had a stopgap preamplifier with a resistive combiner in for mono which worked but I was never happy with as it was a 5 min lash up to keep me running.



By my reckoning there are 4 main ways of getting to mono playback to discuss/experiment with.

1. Mono cartridge with no vertical output
2. Parallel strapped cartridge
3. series strapped cartridge
4. Summing in the preamp/phonostage/DSP


All are worthy of discussion and consideration, even if some end up being considered non optimal. I'll admit to not being a fan of parallel strapping even if that is how most if not all current mono MM cartridges are setup.



I'll add some more when I get time, but at least the thread is started. Oh and I fully expect there to be a stylus size/profile argument at some point 🙂

Just wondering, for systems with not a lot of low end performance, I know manufacturers boost upper bass to make it sound like it has more than it really does. How much boost is acceptable to you guys? For example, with my boombox I don't have much low end, so I eqed it a bit and boosted the lower end. It looks like this: frqrsp.jpg - Google Drive

I can't decide if this is too much or good enough, would this be enough to muddy up other frequencies? I've heard not to boost midbass because you lose low end detail, so I stayed away from that, but how much boost is acceptable that doesn't sacrifice detail or definition?

visco elastic polymer Aka goo 😉

Whats the difference in effect from:

Speaker cabinet with Hard mounted baffle and drivers mounted on it, then adding goo and the extra baffle.

Speaker Cabinet with hard mounted baffle on it - goo. - baffle with drivers on it.

Im sure there are more options but i hope the people answer Will Take into consideration that i dont understand what specificly “we” are trying to gain from constrained later dampening of baffles!

Hi all. I'm hoping to build a WAW with my Alpair 7ms once some plans are released. I'm a bit confused about how to do the crossover as I've seen a few options such as using mini dsp, hypex plate amps, and a PLLXO (which I'm not sure how to implement). I have very little knowledge on this kind of thing and I've been trying to find out more but I haven't had much luck.

I currently only have a couple of integrated stereo amps so I was thinking of going with a minidsp 2x4 HD, but I've read conflicting reviews on it, some people saying it's great and some people saying it sounds no good. So then my other thought was to use a couple of plate amps (if I'm able to return my recently purchased amp), but I've not seen much info on how good these actually are, especially the cheapest ones which are about £280 per amp (for the hypex ones).

I'd appreciate it if anyone could give me their opinions on any of these things or any other suitable alternatives. I was also wondering how to actually implement a PLLXO if I were to go down that route. My apologies in advance if there have already been some similar topics, but I've not been able to find them and I think I'm just about inside my returns window for my amp still if I need to do that, so I can't waste too much time trying to figre out what's best 🙂

Hello all,

I ordered Edcor WSM600/15k which is a tube preamp input transformer by mistake instead of WSM15k/600 for a DI box project.

Can I connect it backwards as an output device?

If so do I need to do some compensations?

Thank you

Glass Painter

Constructed an electrical first order high pass filter on both a midrange and tweeter. The two components used were a series capacitor to resistor. The electrodynamic drivers in this study are balanced armatures.

I cannot figure out what the inherent difference is between the two capacitors used (SMD vs. Thru-hole).

SMD capacitor example
TAJB226K010RNJ AVX Corporation | Capacitors | DigiKey

Thru-hole capacitor example
TAP226K016CCS AVX Corporation | Capacitors | DigiKey

The lower curve in both the frequency response measurements are from the SMD components in the crossover. Everything else remained the same. There can't possibly be inductance in the SMD parts, can there? I

Any lessons to teach this guy?

MIDRANGE


TWEETER

Hello everyone. I have three-way loudspeakers with a second order filter. The mids phase is reversed. Would it be possible to use a first order only for the tweeter without causing any phase issues between the tweeter and the mids speaker?

BR

Toni

Hi all,

A few years back I built a MLTL speaker based on the Jordon JX92S and Vifa XT19TD00
Tweeter to match JX92S

Jordan JX92S Fullrange Loudspeaker Driver / Transducer

XT19TD00-04 – Tymphany

I’ve always been curious as to whether a dsp crossover would improve the sound.

What with a bit of time on my hands and a couple of hundred quid I decided to take the plunge....

Anyone know where I can buy a 4 position terminal block for the larger amps like the Korean board style block where they accept 10 or 8 gauge wire ?

Hi , i have this power supply with a suspect transformer , i have searched the info on it but cant find anything , are these available or is it a new board job ?
Its from a dell monitor ..

I have a Carlsbro gdx-7 300 watt amplifier
The problem is when i connect a mono signal into channel 1 with 1/4 jack
it works fine. But the gain is only turned up to about 1
& the master is not even at 1 & its so loud...whats the problem?
Any help would be appreciated.

Douk Audio Hifi Valve Stereo 6J4 6P6P Class A Tube Preamplifier DIY KIT Full SET | eBay

Looks really interesting, and it's quite inexpensive. It'd be neat to drive my Phase Linear 200 with this... although I'd want to add tone controls.


Charles.

Hi guys, I have some questions about my Zeus Gen X rev. B. The amplifier plays fine, but I think that rail voltage is a bit low. In the past I had a similar Zeus, but it was a rev.A and the rail voltage was +/-58 V. My actual rev. B, instead, measures +/- 49.2 V, no matter the input voltage from 9.5V to 13.7V (so, regulation works).

I made a quick measurement without load: since the distortion at the output start to rise exactly at 34 Vrms without load (theoretically 289W/4ohm @ 0.01 % THD), I thinked that the rated output power cannot be reached (325W/4ohm @ 0.01% THD), ending that the rail voltages are too low to produce full power.

With 13.74V input, these are the TL494 readings:
1: 1.86V
2: 1.86V
3: 3.08V
4: 0.426V
5: 1.413V
6: 3.37V
7: 0.0024V
8: 13.74V
9: 0.914V
10: 0.830V
11: 13.74V
12: 13.74V
13: 4.87V
14: 4.87V
15: 4.87V
16: 0.027V

Attachments:
PSU fet, gate and drain waveforms with 13.74V input

Hi, new to this forum. Hope someone can help me out. I am looking for the tray cog assembly for a Mission DAD7000. Hopefully someone has a parts machine lying around. You can reach me at lawaudio@gmail.com Thanks in advance.

for the gurus:
As stated above,
Is anyone aware of a PCIe (4x 16x, etc.) audio card
solely with S/PDIF out? (i.e. sans surround snik-snak, etc.)
this has nothing to do with cheap (saving money), but pure, dedicated quality.
jus' wonderin'...

So I rescued this kit guitar from a kid in another city who’d not realized that he would have to wire it up. Not a problem. I thought. Anyway, I wound a pair of humbuckers, and I build a test guitar so I know that they are functional, wired up the controls as per a 50s wiring diagram and YouTube tutorial, painstakingly and frustratingly loaded all into the guitar cavity and nothing. It’s fair to say that I am very much disappointed. I am including a picture of the controls circuit and if anyone has a few minutes, could you kindly check my work. I am more than willing to post more, detailed pics if necessary. When I touch the metal housing on the cord, dead quiet, natural state is slight hum and no noise, no switching noise, no pot scratching, when I touch the metal housing on the switch, all kinds of ungrounded noise. That’s all I got right now. Thanks to any responders...

Hello everyone.
I'm in the construction phase of the next speakers, I have already bought some components but I have doubts about the mid driver.
The driver for hi frequency is the FaitalPro HF108 compression tweeter using the B-52 PHRN as a horn. The driver who will cover the sub bass area will be the B&C 15PS100, and my doubts lie in which driver to use between the tweeter and the low driver.
With the mid driver I would like to cover a zone between 150HZ and 1200-1500Hz and I'm wondering which driver could be better to cover that frequency range. I have thought about FaitalPro 10PR300 or 12PR300 drivers, Which of the two drivers would perform their role better?
I wish I had a great sound with great punch
Regards.

I have this old tube line level preamp that someone built years ago and it sounds wonderful. I don't know who built - an audio friend of mine sold it to me claiming it was some prototype. I forget who he said did it. It uses 6 12AX7 tubes - 2 for the line level and 4 for the phono section.

Over the recent lockdown, I thought it would be fun to replicate the line level portion of the preamp so I could use it in an office system. I've built a few pieces of equipment over the years and this seemed simple enough.

It uses a 290V B+.

The schematic I drew in Kicad after carefully examining the existing circuit. I believe it is right. I've built the new circuit exactly the same as the existing circuit and yet I am running into a lack of gain. The preamp "works", there is very little noise, all the plate voltages test the same as the existing preamp. Anyone have any ideas? Thanks.

Apologies if this isn't the correct forum to post this in...

I'm a big fan of the sound of classic samplers - EMU, Akai, EPS, etc. I use them often in my music production. Unfortunately none of these samplers operate in a passthrough mode, allowing me to use them as an effect. I have to sample the audio (in short chunks) and record it back in to my audio recording software.

I've built some DIY audio gear in the past, and enjoyed it. I'm always looking for a new DIY project, and thought maybe building my own 12 bit effect unit could be my next one.

I've done enough research to know that it's more than just the converters that gave those samplers their sound. In addition to the AD/DA, I'd like the unit to have a high pass and low pass VCF, and possibly transformers on the input and output for additional coloration options (with input and output gain).

Any ideas, suggestions, or recommendations would be greatly appreciated!

Re the CDM1 (mk1) mechanism.

Does the spindle motor shaft come out from the top, or the bottom? Must I remove the disk turntable (how???), or the motor rotor to get it to come apart?
Thanks

Hello,

I'm looking for a vintage old school 2P3T ceramic single wafer rotary switch for a restoration project I'm working on. Something by Centralab or similar ?? I undertand there's modern variants available, but would like to replace with something more time-period appropriate to the original build.

NOS or used working, OK.

Will consider a quantity, if available. Prefer an exact 2P3T, but will consider maybe a 3P3T or ??

Shipping to San Francisco, CA.

Thanks in advance!!
Greg

10-12” midwoofer for 2-way with SEOS-10/12 that goes to 35Hz

Hello,

So I’m basically looking for what the title says. I want to build a 2-way with a SEOS-10 or 12 crossed at 1,000-1,500Hz. I need a 10-12” woofer that’s able to play from 30-40Hz to around that XO either ported or sealed in less than 85L (3 cu ft) and cost <$300.

Here are some suggestions I found myself. Not sure if all of them matches my criteria:

• 18Sound 12NLW9300
• Aurum Cantus AC250
• Beyma 10BR60 V2
• Beyma 12BR70
• BMS 12S305
• Dayton Audio DS315-8
• ETON 11-612C8/50RP
• Faital Pro 10RS350
• Faital Pro 12RS1066
• Peerless SLS-P830669
• SB Acoustics SATORI WO24P
• SB Acoustics SB34NRXL75
• Seas H1316-08 CA26RE4X
• Seas H1411-08 A26RE4
• Visaton TIW 250 XS
• Visaton TIW 300
• Volt BM2500.4

Any recommendations or suggestions?

Thanks,
Søren

I've been searching for examples of using Mosfets instead of BJTs for VI Limiters, but could not find any.

In some amp designs, the VI Limiters are having troubles robbing enough base drive current from the drivers, so they're unable to fully implement the calculated locus to keep things under control into the SOAR.

So despite having properly calculated values for a given locus, the limiter isn't capable of properly enforcing it.

I've tried using CFP combos instead of a single BJT, and that does bring some improvement, although not always quite enough to fully enforce a locus.

Using Schottky diodes in the BJT's collectors instead of regular ones also improves things slightly, but far from enough.

So I was thinking if possibly using MosFets instead of BJTs could make for a more forceful action and perhaps it would be able to better enforce the locus.

Has anyone thought of this and tried it?

Hello,

I'd like to build the best quality possible parabolic speaker as a prototype first and then for home offices.
I have made few designs, gathering the pieces to get the parabolic part done. What I miss is a partner to guide me on the electronics/acoustic parts. I'm capable of learning but it will take way more time than having a partner.
Ideally we'd share the design principles here so that anyone from the community can build his own one.

Here are the few first designs, any help or feedback would be much appreciated !



modele — ImgBB

cheers,


JLo

I have previously built two headphone amps (non kits-one each tube and solid state) this will be my first speaker amp build. I have my SSE board in hand, the parts to populate will be here Tuesday. The output transformers will be Edcor GXSE15-5K not yet ordered. I will be using a Triad 200mA choke in the power supply along with a motor run cap (all on order). The speakers I do not yet have. I will be ordering some small bookshelf style speakers hopefully 3way to be run by the amp build in question. The source will be a turntable with built in preamp. All is to live in a small dining room for dinner music and maybe later to a small living room. I have not decided on what output tubes I will settle on but plan on building for the standard choices of EL34, 6L6 or KT88.

The Hammond 374BX interests me in that it has a tapped primary (I am 120v nominal). Many seem to be happy with this though a few complained they run hot. Others have used the Edcor XPWR035. The Edcor does have a larger overall size which may add to longevity.

My question (finally) from a heat or quality or longevity standpoint ignoring cost, which would be the better choice ?

I also fix antique radios and we are sensitive to heat in 80 year old transformers.

Hello there,

Im jaap, living in Arnhem (Netherlands) and got recently intrerested in building speakers.

A friends dad used to build speakers, after his dad died they sold their house. while moving he found 2 broken speakers and asked if i wanted to have them. bought wrong parts, and started reading a lot about building speakers.

Now i've build 4 pairs and 2 subs.

Completed this build yesterday!

Hi! I have a mobile 2.1 PA speaker system which i used with a cheap chineese TAS5630 2.1 board. It was not not the best but it served me for almost 2 years, but it got faulty recently. I'm trying to research about the topic but I could use your opinions and suggestions.

I need for the stereo part at least 2 * 100-200 Watt and for the sub ~300 Watt @ 8 ohm(the very minimum). Furthermore for the sub it would need to be have a low pass filter.

I thought about the "plate amplifier design" too which is mostly used for the mobile 2.1 PA setups you can get.
Are there any shops for oem/diy with a selection of this plate amplifiers in europe ?

Like this for eg🙁bit overkill and it's in the US, but this kinda setupp)
B-52 Matrix-1500 BBE 3-Ch Plate Amplifier 1200W


The original board I've used:
UNISIAN TAS5630 2.1 Audio Amplifier Board 2X150W+300W Digtial 2.1 channels Class D High power Amplifier for Home theater system|Amplifier| - AliExpress

What would you recommend me to do ?

Hi
I finished my amp and the rectifier tube red plates after about 1 minute. Without the tube there is no problem, and all of the Heater/V test correctly, The Bias is -150. I took the choke out and the tube did not red plate for over 5 minutes so I put back the 150 ohm R and then it red plates.
I checked the fets for a short and there is none, there is no misplaced parts or solder bridges. I tried two tubes and it is the same. I sent George a private message but there is no response. I am staring to think that the board has a short in the tracings. Any help would be very much appreciated. Thanking you in advance.

Donald

Two players with the CDM-1 Transport, see pictures. The Marantz CD34 and the other Marantz CD74...The CD74 transport is the Japanese version if I'm not mistaken. can anyone tell what that large nut is there, as its not on the CD34. Also, seeing how they are almost identical players, The CD34 plays every cdr thrown at it, while the CD74 is temperamental with some home recordings. Now oddly enough, my Revox B225 has issues with the same identical disc's as well. I don't play cdr's often as I only have 12 home recordings, but I am curious about the why?

I've built a preamp, and it's not working, my amp/speakers do not want this thing in the circuit, bunch of popping, hissing, buzzing.

I have the input, output, DC wired the same as in my previous preamp, which works fine.


I used spare leads from resistors to make some connections in the circuit, could that be a problem? everything seems to be connected correctly.

I used BC547C instead of BC549, but they're basicaly interchangable, as far as i know.

As mentioned in the topic, I need a service manual for the IA60 - EM1051 rev. 1. I can find the schematics for the newer rev. 3/5 but not the rev. 1. Pcb and design in general are very different in these. Thanks a lot 🙂

Recently I stumbled across a circuit for push-pull 807's that directly drove a pair of electrostatics. Unfortunately I omitted to bookmark or download the data and now I can't find it. I believe it was in a 1940s magazine but that's about all I can remember. I've checked the RTV&H index but it wasn't there.

Anyone?

Hello everyone.

Long time lurker, first time poster.

I've spent the last six weeks chasing demons inside this amplifier and I'm running out of ideas. I'm a bit of a newbie when it comes to...well anything amplifier related really so I'd love any advice.

I purchased a G&W T2.6F a number of years ago which worked wonderfully for about 6 months. It then developed a strange flickering noise in the left channel which has since persisted. I haven't used it in a number of years due to this, however I've recently pulled it out of storage to use with the Audeze LCD2.

Its an excellent pairing and adds a lot of life to otherwise clinical planars so I'd like to save it if at all possible. My other amp is an audio gd which sounds excellent but is a little too 'reference'.

The noise can best be described as an intermittent static like flickering noise, but only in the left channel. Sometimes its there from the second I turn on the amp, at other times it appears after a few minutes of use. I can adjust the left channel trimpot low enough to a point where I don't hear the buzzing, however the music sounds terrible. Since beginning, I've:

- Isolated to left channel for the headphone out only. The line out does not seem to have this problem but it looks like the line out does not pass through the tubes. I've also used different sources.

- Switched tubes around as well as inputs. Left channel only.

- Changed thermal paste on heatsink connections.

- Resoldered and cleaned the alps pot.

- Removed solder and resoldered almost every joint on the board.

- Checked caps and resistors with a multimeter. Everything is within spec.

- Insulated the back of the board from the plate it is attached to just in case a joint was accidentally touching the plate.

- Changed the 50k trimpots to new ones.

Next up, I was thinking of soldering the tubes directly to the board with some extension wires in case the tube sockets are the issue.

I've included a photo below. Would appreciate any and all advice!

Hello guys,

I've posted to a dedicated topic in "Planar and exotics" ( https://www.diyaudio.com/forums/planars-and-exotics/352353-project-parabolic-speaker.html ) but I feel this could be part of a broader conversation.


Thanks to the help I received on this forum, I've mostly finished my prototype of a parabolic speaker for home:



It works really well and my kids are stuck to it.

So I'm launching a short questionnaire to test the appetite for a parabolic speaker on the market.

Spend it 5mn, it would really help me !

A parabolic speaker at home !


Have a great day !

Good morning all. Nuno, living in Braga. Not consider myself an audiophile, or at least a extreme audiophile, but like very much of vintage audio stuff. Currently, my audio stuff is simple...

Sanyo DCX6000 receiver
Technics M24 tape deck
Revox A77
Thorens TD166MkII
Sony MD
Sony 5 cd changer
Pioneer 6 cd changer (need for repair)
8 track player/recorder
A Philips compact system wich includes DCC91
A Yamaha 5.1 receiver (bought when I’m not in vintage moode yet lol)

Plans: buy a tefifon (just for fun)

Currently making an audio selector based on Arduino

Cheers, and keep safe!

Hi,

I bought this marantz 2216b dirt cheap for fixing up, one channel was blown, taking it's pre-driver, power transistor and fuse out with it along with Q706, I removed the 4 main power transistors and powered up using a current limiter, found a bad cap as well, these are all fixed up now, also issue on the other channel on the tone control board, which I have also rebuilt, new caps, and some new c1845 & ksa992 from farnell. The sound is great from the headphones, and I also checked the DC voltages on the output coil & at the base of Q701 & Q702 and its reading 20mA so looks good. Voltages also measure good. I am nearly ready to install the power transistors, I set the bias control resistors to full resistance, I have one question though the Lamps 0.6v VT01 & VT02 one has been replaced with a fuse on the other side of the PCB, I presume these are to limit current spikes and help protect the output transistor, is a fuse ok here? I have looked for suitable replacements in farnell, but 0.6v is impossible to find, what is the best to put in here, I have some fuseable 10ohm resistors, I presume the bulb acts as an inductance. Any advise? What do people use? Thanks.

STK4171V, Power Amplifier IC, incl. Profile Heatsink 160 x 70 x 50 mm


STK4171V, Verstarker Power Amplifier IC, incl. Kuhlkorper | eBay


You can also make a direct offer without eBay:
EMail me.

I have a strange, maybe simple, question. I was checking out the inside of my preamp the other day and noticed they used TL071CP op amps, but some were silver painted and some were regular black.

I'd love to know why!