Are there space-saving solutions for a waveguide? And how do I know how big my waveguide should be. Can someone explain all this to me? 🙂

I want to use 1st order crossover, 2nd order only if its a MUST.

For the tweeter i selected planar GRS PT6816-8 8" open back , which plays down to 400Hz and from there roll-off starts. However, at 400Hz there is about +6dB peak comparing to 500Hz- 3,000 Hz range when it plays at 90dB.
At 300Hz, it outputs 87dB, but at 250Hz only 80dB
From 3,000hz it rises steadily up to 100dB........ Driver is rated at 94dB

My question is, can I cross it to woofer at 1,000 Hz? With first order?
Books say, the driver must play 2 octaves outside of such X-over.

I dont intend to play music very loud or even loud. Room is of avg size for a living room.

By the way, if I match it with 15 inch bass-mid woofer, is it OK with cross @ 1,000Hz? 15inch is rather large.....
But, I've seen speakers with 18inch woofer crossed at 700Hz, so i guess its ok?

Thanks
Any suggestions welcome.

Hello! Soon I'll be moving out from my house so I need a pair of speakers that I can carry with me. They have to be active because I don't want to carry around an amplifier when I move. It also has to be extremely compact, 4 liters is the absolute maximum but I'd like to stay below that. It won't have to play loud, but I'd like something with a bit of headroom and decent bass extension. It also has to be very cheap.
For this reason, my driver choice for the woofer has fallen onto the Dayton Audio TCP115-4. I want to use the 4 ohm version because it's more efficient.
It goes pretty low in a 2,5liter PR (or BR) enclosure tuned to 60Hz. It's also very cheap.
I think I will use a 5" chinese passive radiator. I will have to measure the tuning afterwards but it should work ok, if it has enough excursion. The SB acoustics models cost more than the woofer!

But I need to find a tweeter. I could either get a new tweeter when I purchase the woofers, which will have to be cheap and of at least 19mm (3/4") in diameter since the TCP can't cross very high, or also a used one. I also want it to have a compact faceplate to keep the two emission centers as close as possible.

After taking a quick glance on Soundimports, it seems that those models are the cheapest.
HiVi T20-8
Dayton TD20F-4
Dayton ND25FA-4 (slightly more expensive)

I don't trust HiVI too much, I've read stories of out of specs drivers, I don't know it true so that's part of the reason why I'm asking.

If I want to get a used one, I could opt out for a pair of Ciare CT190 which cost as much as a pair of T20-8 or a pair of Hertz HT20 (which cost way less). These are also great because they have a metal mesh so they don't get damaged when moving the speakers! Can't find much info about the Hertz, and I'm not too sure about how well the Ciare will tolerate a 3500Hz crossover point. It also has a poly dome and they don't sound nor measure as well as paper cones or silk domes, at least according to my very limited experience.

For the amplifier, I couldn't find anything. The Lepai LP40PA is perfect, however is too expensive given the nature of the speaker. I could just buy an amplifier board and place it inside the speaker, but then cooling would become an issue because the speaker doesn't have a single hole. Do you have any ideas on recommendations on this?

I'm attaching the simulated response (+0,5ohm series resistance)

I have re-tubed my TT presignature with all ne matched el84 valves and need to set bias. Thesere are two trimmers inside.
I can only find information on the signature model and wonder if anyone has a service sheet or any information on how to set the bias properly?

Hello all,

I'm designing my first subwoofer around a 300 euro budget. It will run in a stereo 2.1 setup for music, in a small room. So my preference would be an f3 just below 30hz, keeping it small, and a focus on SQ rather than SPL.

I landed on the following components, but i'm open for suggestions:

• sb acoustics sb23mfcl45-4 (I assume the 4Ohm version is preferable) - 140 euro
• Dayton SPA-100D (or monacor SAM-200D for double the power if necessary, same price) - 145 euro

The maximum box size I am willing to place is 30x30x50cm, which amounts to a volume around 34L.
Setting FS at 29Hz gives me the following TF in WinISD:



Adding filters:



Now, my question is is it safe to assume that the SPA-100D will HP roll-off around 23Hz? Because if I go below 22Hz we will hit Xmax at 100W. I will probably never use this amount of power, but it would be great to know my design can handle the full output available.

I have read a review of the monacor sam-200D, where the roll-off is desirable. So would I benefit from the 8Ohm version of the driver (Which has slightly worse properties?) and running the 200W amp to get a safe roll-off?

Excursion at 100W:



I designed a slot port for the full lenth of the cabinet, which means 2cm x 26,4cm and a lenth of 50cm. 2cm seems oddly small, but I assume it won't be a problem? Port resonance at 350Hz.
Air velocity at 100W:



Which is right around the recommended maximum.

So for fun I went to designing in fusion 360. The big cutout is for the plate amp. Is this the correct way to design a slot vent? I will add some bracing later.



As this is my first attempt, all general feedback is welcome. Regardless of the previous questions, would you think it is worth to design this sub for SQ music application instead of buying an entry level 300 euro sub or saving up for something like a rel t5x or svs sb1000? Please keep in mind that i don't have any way to measure and I dont have any way to EQ outside of APO.

Thanks in advance.

I am think of building a couple of subwoofers for both music and home theater. I am currently running a single 12" powered sealed sub from the sub output of my receiver, crossed at 80 Hz. I also run a dedicated 2 channels power amp to my front speakers which are Magnepan MMGs, which are dipole panel speakers having very detailed sound down to about 100Hz. The sub helps for the very low frequencies, but tends to have the monotone boomy sound, even if I try to adjust the crossover. In other words, it does not integrate with Maggies very well for music.
Rather than building powered subs with a control panel on each, I thought of hooking a mini-dsp 2x4 to the front speakers pre-out and using it as a crossover between the Maggies and the subs. I would have to add 2 channels to my power amp for the subs, which is easy because it is modular and VTV can add a 2x500W hypex module for a very reasonable price. The DSP would also allow me to apply room correction to both sets of speakers. Another advantage is that I could experiment with the sub design without messing with the amps. Of course I would have to build more "musical" subs, thinking of ripoles now. Do you think this would be a sound design? Are there any downsides?

My start/stop button does not work and the switch is always is in on -position. It looks like the switch uses red LED (considering the age of the device it can be also a bulb) which does light up because it is likely dead. I can’t see a detector on the panel so I’m not sure how it actually works. I wander if anybody has an experience of repairing the switch or got the circuit diagram.

Hello!

I have two khadas toneboard 1 for sale. Got one when was working on my soekris dac chassis to keep music playing. Was very impressed with the quality and sound of that little dac so got the second one. Now when my dam1021 is finished I am rarely using it. Slowly cleaning my gear I don’t use often so these two are for sale. One has maybe like a month of use and the other probably a couple of hours when I was checking that everything is ok upon arrival.
Price is $70/per board shipped in CONUS, PayPal friend or family or please include fees. Thank you for looking!

Hi. Newbie poster here so be gentle.
My new project is converting an old (1940s?) wooden radio into a mono, three way, 24v, bluetooth capable speaker for camping etc. but i have run into a modelling issue that I cannot find a previous example of. The bass is being handled by a ported dvc visaton W 130 X driver which will be powered by two separate channels of a 4 channel dsp amp. (zoudio AIO4CH)
My main issue is how to model this in winisd for the port? values are given for the driver according to how the voice coils are wired but there is nothing suggested for this situation where each voice coil has a separate amp channel powering it. my apologies if i have missed this question elsewhere.
Thanks for any advice including why this whole project is misconceived.
NB. no antique radios were harmed in the making of this speaker. It's a 1980s reproduction which didn't work.

No longer needed

Does anyone have a quick tutorial of proper bias procedure for Nakamichi PA-5 available? I have the owner's manual and it says to use shorting pins on inputs. Does this mean just run a small rca from red-to-black on left channel and then do the same on the right channel?

For sell
Speaker stands.
Couple,
Totally six column
High 38,5 cm without base
The mutual distance between columns is decided by who buys.
They are (if you want) air spring (instruction comes with it but, for information the weight supported is given by spring gasket's thikness )
Come without basement.
You could glue on rocks, , marble, Wood, as you prefer.

Price is € 600 included shipping in EUROPE

I bought a second hand aikido octal kit. The preamp is just finished. In the kit there was an a3 stepped attenuator. There where no instructions but all resistors where in marked bass, so I solder it togheter. When finnished I wanted to check that everything is rigt.
But I only got same Reading (around 100k) when messuring between input and output regardless off switch posisjon.
Shouldent the value change? Not much to do wrong with that pcb.

a few pairs (4 at least) would be highly appreciated
pls. genuine only
cheers
zs.

Lundahl LL1671 Transformer 1:2 Step Up.

Are there any disadvantage to use the Lundahl IT LL1671 in 1: 2 configuration over 1: 1 configuration ?

Maybe some less bandwidth ?

http://www.lundahl.se/wp-content/uploads/datasheets/1671.pdf

Hi, I'm putting together a TDA2822m amp but I've noticed in the datasheet schematic that the Boucherot cell is placed after the output coupling capacitor as opposed to right at the output pin like many other IC's recommend.

For example this is from the datasheet of the TDA2822m



Where as this is from the LM386 datasheet



As you can see the output RC zobel networks are in different places, is the placement on the TDA2822m datasheet a mistake or does it not matter where I place it? I've taken apart a commercial clock radio with a TDA2822m and the zobel network was placed right at the output of the IC before the coupling capacitor.

tl;dr is it better to place the zobel network before or after the output coupling capacitor?

Thanks! 🙂

I'm looking for data for ITT diodes type Z3B560, if someone could point me in the right direction - thanks in advance!

Just got rid of my home made 8" subwoofer and bought a low cost 12" active subwoofer. So far so good....however

I have it hooked up via spliced speaker cables in parallel to my power amp output that go into the high level input connectors on the subwoofer amp.

In trying to adjust it to a level that blends into my system I'm finding that I have to have the low level cutoff right at the bottom lowest frequency and the total output level turned right down to near zero.

This causes a problem because the pot adjusters are the click type, not continuously smooth, so when I'm almost at the right spot I'm finding one click is too quiet and one click up is too loud.

What I need to do is rescale a little so I'm nearer the mid point and have more adjustment control.

I used a voltmeter on the input resistance on the high level input and its around 650 ohms.

I opened up the subwoofer amp and the level adjuster pot is a 50k unit.

I'm stumped at an easy way to re-scale this thing so the level has more adjustability.....is there an easy way?

I am necessery to repair this micro seiki ... please some of you have service, no user, manual?
thank and a nice day

GP Italy Treviso

I'm debating on whether to push the tweeter and mid back to time align with the woofers in my 4-way system. The problem is that I am building this in a cabinet so there will essentially be a shelf very close to the tweeter, I am going to be using felt to soften the baffle diffraction all the way across the baffle, at least that is my plan for now, so I can add felt to the top.

The question is this, is it better to have some damped reflection and no time alignment or is it better to have time alignment and some reflection?

I hope this is OK to post in Pass Labs... Talking about the old Adcom 555, but it is a Pass design!

I've been selling replacement boards for the GFA-555 for some time now, and I am about to design new versions with some subtle improvements.

I have a question about thermal tracking. I read somewhere you were describing the thermal design of the 555, and what I gathered, was that Q617 and Q619 provide some measure of tracking with temperature... But I wonder if this is one of those cases where the physical layout doesn't match the designer's intentions. Should these transistors be mounted on the output module heatsinks, and not on the input board?? The 555 MK1—as manufactured—actually has quite a pronounced positive thermal coefficient. At idle, each output runs about 50mA, but when hot, this can rise to as much as 150mA, and it takes the amp longer to cool down because of this.

Was the thermistor TH601 in your original design? Maybe it's not even necessary if Q617 and Q619 are mounted to the heatsink?

If this is the case, I can design new output module boards to include these transistors.

Thanks for your consideration, and the excellent designs that I continue to learn new things from.
-Chris

Does anyone know which mosfets to use for the outputs? Since the irf3710z are not available where I live and Originally it had rfp40n10 outputs but the amplifier is protected at 1ohm and said to be stable at 1ohm the amplifier uses hip4080ipz

Because I found it to make the most sense engineering wise. What do you think of it? Will I be able to successfully power it with a 12v wall wart (acceptable sound)?

HIFI Philips Little Giant TDA1387 decoder

KiCad 6 "Update PCB From Schematic" produces PCB footprints nets, pads .. but no vias to connect them. I only wish to gerber a simple 2-layer PCB and have some confidence that a fab will accept it. Please tell me how I can complete update.

I am actively putting together two systems:
System 1 - 5.1 for our home which serves as home cinema and home studio and used for studio tasks usually about once a week. This is an open plan type home that contains the kitchen and adults bedding in one room. Another same sized room is attached, with an amenities' room separating the two. A full length room run alongside the two main rooms and serves as my workshop, large double sliding doors from main room to workshop. These areas are contained in a square house structure

System 2 - 2.1 mobile box with 3 aux amplifier channels outputs, for a portable setup, which can supply extra amplification on demand with extra speakers. This will be installed in the workshop in a manner that allows easy removal. Mainly for listening to music while I am working, as well as for testing stuff without having to rip into the home system (I hope the logic for common device models is now apparent)

Request
The living room is not a place for a PA system, neither is the sound quality and ability of most of this sized PA systems out there for portable use acceptable. System 1 will be in operation here virtually 24/7. Think of these as being in the same category as the high-end Japanese audiophile disc players that feature mic inputs. I do not believe that anyone would be upset about such a disc player being discussed in a Hi-fi forum, so please may I request that discussion on an amplifier with the same feature doesn't upset anyone's sensibilities
Please regard these as a Hi-fi want to be setup. Both will be used for audio and video reproduction and appreciation and when liquid courage hits the spot, these systems should invite one to grab something and let loose

Desired feature:

• An ability to keep electronic hardware and speaker driver models common to both systems
• Emphasis is on quality quite nighttime sound reproduction and ample headroom without loosing composure for other times
• Switch power supplies (desire to stay away from "ring cows")
• Tubey audio signature (prefer the sound of the 300b amp for audio)
• Engineered with the ability to input a live performer or two on demand (In other words, beautiful reproduction of prerecorded material, containing the "studio to mastering" process internally for a seamless jamalong)
• Low pass channels to be either about; 400 clean watts into 8 ohms - 400 clean watts into 2 ohms - 2 x 200 clean watts into 4 ohms each
• High pass channels to be about 100 watts clean into 4 ohms

This thread is for the class d amps that will be contained within

I have been saving for this project for a while, and in the meantime pouring over catalogues and specs and pestering folks with uneducated questions and ideas. Time to get to work on these, so I have ordered these items:

Signal IO
This unit will get fitted inside the amplifier case and provide most of the signal IO and act as the brains and system overall volume (has remote) as well as individual channel adjustment
4K@60Hz HDMI 2.0 Audio Extractor Converter DTS AC3 5.1CH Digital Audio Decoder ARC SPDIF Coaxial PC-USB Bluetooth Audio Input

Amplification
To be trailed as the low frequency amp
AIYIMA 500Wx2 Digital Power Amplifier (PSU on the board) x 1

To be trailed as the main channels amp and low frequency amp
HIFI Power IRS2092 500W Mono channel Digital power amplifier x 5
+ Lusya Dual DC 36V Output LLC Soft Switch 500W Switching Power Supply x 1

To be trailed as the main channels amp and bench amp
TDA7492 Amp Class D High-Power Digital Amplifier Board 2x50W (to run in bridge mode as a mono amp) x 1
+ 24V switching power supply board 4A 100W x 1

Speaker drivers
Low frequency
Dayton Audio RSS265HO-44 10" Reference Series HO DVC (delivered) x 1

Main channels
Already have a number of various pairs of bookshelf types on hand. Working on an interesting 6" coaxial speaker alongside this project, I am using some very interesting sounding drivers that I auditioned and bought, but I fear derision on my choice here

Reason to post thread
I am getting some promising looking kit that might help me acquired the desired sound system. Please guys, help me with peer review of my choices and suggestions to gear that I may not have noticed. I know create folks out there will have some great ideas too. Please help with mod suggestions as well as education pointers in anything I may be lacking. This will also be a log for me to help keep track of my project

Thanks and regards
Randy

Hello
I have tried to post in the section, pc based. Daphile thread but cant find how to reply to the thread without adding to an existing reply. Any ideas.
Thanks
thyristor44

I am looking to buy four pieces of 2SJ79.

I was looking at the Seas A26 kit and was intrigued by its "naked" use of the 10" woofer. I seem to recall that Reference 3A favored the same methodology -- i.e., running a woofer "naked" without a crossover while using a tweeter to fill the top.

My question is whether there is a similar, two-way design using a 10" or 12" woofer for cabinets (sealed or vented) that are much larger, say 85L or 3 cubic feet. The goal here is to hopefully obtain the same level of midrange purity while also getting a bit more bass.

Thanks!

I am looking arround to commercial products like studio monitor devices, where is inside PHL Audio transducers.
Thanks for advices.

Now that payments are being made and production is starting for the 2012 Shigaclone

http://www.diyaudio.com/forums/digi...affordable-cd-transport-shigaclone-story.html

I thought we should start a new thread with recommendations for how to turn this latest version into a giant killer of a transport. First of course, great thanks needs to go out to our friends in Poland, Peter Daniel, Tvicol, Jazz35, and anyone else I forgot to mention. None of this would have been possible without this team's collective work.

With Tibi's okay it seemed like a new thread would be a good place to start this phase of discussion for the 2012 Shiga. My proposal is that we work on creating a transport that can go up against the likes of the ML 31.5, CEC TL0, Linn CD12, Wadias etc. I know there is no one "best transport in the world", just as there is no single best of anything in high end audio, but the plan is to try and get to a level where a tweaked Shiga can stand on its own against the most highly regarded transports of the past and present.

I’m not suggesting the new Shiga won’t sound good at the start – I suspect it will sound pretty darn good. The hope is to take it to the best it can be.

I further propose the following as a baseline definition:

• Use the 2012 Shiga design currently in production as the starting point
• Post (or link) the latest production schematics, BOM, PCB drawings etc
• Use this thread to identify from the original Shiga thread(s), and any others, the key posts made to date which discuss advancing the design. I know this sounds vague, but rather than everyone searching through 600+ pages of one thread, plus any other related threads, I'm hoping those who were part of some of those original tweak discussions can provide links here so we can have one place where this information has been filtered.

Once we start getting these units and have had a chance to understand what they can do, perhaps then we can identify the areas where tweaking may prove beneficial… areas like

• Power supplies (parts swap, or going further like considering a Bobken)
• Clocks (although Peter has some interesting things to say about this)
• Output stage
• Specific component changes
• Chassis and mounting options
• Ferrites and shielding

A lot of discussion has occurred in most of these areas. Many may be a good starting point for the 2012 Shigaclone. Those with test equipment who can help quantify any improvements would be a great asset. (I'm neither a complete subjectivist nor a card-carrying DBT'er. A combination of listening impressions and data would be a great thing to have.) Does this sound like a good plan?

Hello to everyone,
I am quite new in the field of DIY audio! Like a technical draughtsman is not an architect, I am not an engineer either. I have quite good soldering skills and I can handle with (most) technical specifications but I am far from being able to develop or improve anything by myself. But as it is, like most men I am always looking for a new project! Besides my studies (25 years ago) I earned my pocket money in a high-end studio and fell in love with an e-something (maybe E-305?) Accuphase at the time. Now I have discovered the following DIY kit on Alibaba: Accuphase E405
My search on this wonderful forum has unfortunately yielded no results, has anyone already made experience with this clone - Try it or is that a no go?

best regards
Henning

Good day guys, can is use complimentary 1A and 2A smd transistors to replace 1GM and 2GM on this power supply drive board?

2SC4883 and 2SA1859 are excellent part for VAS stage unfortunately they are hitting EOL



2SA1859 ｜Sanken Electric


Very Linear and very low COB value.
Most importantly very fast!!



Well it seems not many good VAS transistor are left.

Dean Slindee started in 1977 with Rabco SL-8E mod, see page 21.
http://www.bostonaudiosociety.org/pdf/bass/BASS-05-05-7702.pdf

Dean Slindee replaced Rabco SL-8E with Stealth One tonearm.
https://radialaudio.godaddysites.com

First I apologize for my ignorance on this matter and for perhaps asking a question that for this forum is obvious. I'm trying to make my first headphone amp using tubes. I have seen some circuits on the internet using tubes, 6k4, 6J9, 6N2, 6N2, 12AU7, 12AX7 etc. but all of them with supply voltage of 12 volts. In my limited experience (Ham radio) I have never used such small voltages... and according to the dynamic plate curves ( ib as a function of Eb with Eg as parameter) and my limited knowledge, with those voltage levels, the valve is very far from working in its linear zone, and consequently its distortion should be high. But supposedly these amplifiers have very low distortion, which seems contradictory to me. My question is: really with 12 volts is it possible to get a low distortion amplifier (and what is the applied concept), or in these amplifiers are the valves just "for decoration"?
Tks in advance

I was tired to solder divider diy patches every time I needed to measure power amplifiers with a soundcard, and also by investigating how to avoid groundloops and mains related interference spectral lines. So I decided to design and build a fully balanced universal analog interface that would change a soundcard to something that resembles an audio analyser like AP, or maybe rather like QA401. I started with using such thing a year and half ago and after getting good results, I decided to make a stand-alone instrument like this. The interface, called MSYS, has 2 channels, one for low level signals up to 4Vrms, second for high level signals up to 40Vrms (at least). The gain and sensitivity is controlled by DACT stepped attenuator. Block diagram is attached, circuit diagram is attached as well, and a photo of the instrument and its rear panel. The circuit uses OPA314, AD797, OPA627 and ADA4898 chips. Dynamic range is high, distortion very low and it makes a useful tool from a conventional soundcard. Balanced input is a must if we measure a power amplifier.

Want to Buy BAD power tubes for research - filaments required to work.

Will pay for shipping too.

Cj

The majority of headphones have quite simply awful high-frequency performance. However, by using either a single ribbon or a combination of ribbons, it should be possible to build a driver that works very well even to high frequencies with minimal energy storage. Also, according to another DIYaudio thread, the ribbon could reproduce an acceptable amount of bass, too - the short length would apparently keep it from "flapping" at low impedances.

Transmissionaudio.com has a picture of a prototype on their page, too.

http://www.transmissionaudio.com/ourribbons.html

The obvious problems with this setup would be weight (enormous) and impedance (tiny.) However, these would likely never leave my desk, and if I can get some metallized Kapton film, it should be possible to etch fine enough traces to get the impedance to an acceptable (1-ohm?) level.

Update. In light of new information about the amp being counterfeit I have removed the link. The question around the preamp conundrum is still relevant regardless, so I don’t want to just delete the entire thread.

Hey guys

I'm building out my first DIY speaker system and hoping for some advice. These will be speakers for my workstation. I will be doing crossover and DSP on my Mac, using the Motu M4 hardware interface and CamillaDSP software.

One thing I am having a bit of trouble with is amplification. Im interested in one of the Purifi 1ET400A based amps (link removed) from China. It comes in 2 versions: one without a volume pot and one with (for a small premium). The no volume pot version was tested and the results were phenomenal. As I understand it though, poorly implemented volume control could negatively affect the sound quality, and I haven't found any test results for the version with the volume pot.

The problem is that right now I don't have a preamp in the signal path. Since the system is being run on software, with volume controlled digitally. I feel it would be foolish to just hook the speakers up to a pure amp - risking hurting them (along with eardrums) should something iffy happen with software volume control.

So how likely is it that the volume pot version of these amps is going to suck?

If I was sure it would just be fine, then that's perfect, my problem is solved. But if it's actually a dicey situation, should I instead find some preamps and opt for the pot-less variant? (I don't really want to add much more to the bill)

—>make speakers for family and suddenly they are going on the ‘base’ of the fireplace instead of actual ‘floor’ … (Well over a foot higher than planned and putting the listening position ear heights and Tweeters at that ~mismatch?

any reason I can’t just flip this over and put the tweeter underneath the rs180 and leave everything as it is?(just need to cut a hole for them in the plywood)

Hi,

I have friends Yamaha M-4 on my desk for repair with burned driver and output transistors on one channel. Of course, all of them are now obsolete. I managed to acquire some replacements for the output transistors but have nothing for the driver pair 2SA968/2SA2238.
I have RS and Farnell distributors in a place where I live, but I didn't manage to find anything on their stock that could be useful in my case.
Found some that are sold on ebay though, but I I think there is a great chance of them being chinese fakes, so I would like to avoid those and find some source that is more reliable.

Does anyone have an idea on this ?

Ive been saying this for a few years now. Decided to do a search on my smart phone 😉.

https://www.nbcnews.com/think/opini...-developed-countries-doesn-t-bode-ncna1008576

https://www.forbes.com/sites/forbes...e-while-iq-is-on-the-decline/?sh=6b8dc2a1b103

Anyone else noticing this? Remember when you had to memorize stuff, do simple arithmetic, read a map, estimate the time, take something apart and put it back together without a video, etc. Soon you will not have to think at all. Are we already seeing the results?

Login to view embedded media

Hi All

Long shot but worth a try.......
I've been fixing up a battered 8000A for a mate. Looks as though the thing was dropped at some point in the past as the volume pot shaft was sheared and the balance pot was missing altogether. I found a good 100K dual MN taper alternative balance pot that fit perfectly and stripped / refurbished the volume pot, re-pinned the shaft (fiddly job) and re-mounted - works great. Only thing is the flat lock nut is missing. I've gone through every spare pot in my stash and none of them fit. Does anyone happen to know what size/thread it is before I go buying replacements? I could be that the threads are goosed and nothing will go on. Other than that, after 2 power transistors, 2 drivers, 1 x DC servo IC, and a heap of caps and resistors, she's up and running and sounding a million bucks.

Hello,

I was wondering what would be the best way to wire a house to avoid ground loops.
I always got a ground loop over my balanced speaker cables.
Earth >Power Calbe> PC >HDMI> TV >HDMI> AV-Reciever >XLR> Amplifier >Power Cable> Earth
I just added a capcitor to the ground of my PC to mostly get rid of the noise but not 100%.
Or maybe decouple the amplifiers ground somehow?

Now I am thinking of rewiring my house what would be the best way to avoid this.
Seperate Ground connection for the amplifiers?

Also I was wondering, should I use the same phase for all amplifiers or is it better to use different phases?

Hello,

does somebody have one of these schematics:

Audio Note DAC KIT 1.1

Audio Note DAC KIT 1.2

Audio Note 2.1

Audio Note 4.1


Thank you

Pascal.

Greetings audiofolk,

I have 2 woofers. The left sounds "weaker" than the right one. Lower volume, less vivid. No crossover. Exact same woofers, brand new.

I have checked everything from internal wiring (cabinet), external wiring (audio cables), the DAC, the AMP and all the cables in between. I switched the speaker from left to right, the right speaker sounds weaker. The "weaker" woofer needs 50% more volume to stay at the same level as the good one.

So... is it the woofer/driver itself that's messed up or am I missing something?

UPDATE
AMP:
Denon AVR-4306
WOOFER:
SB15NAC30-4 (4 ohm, I checked both with a multimeter).
No crossover, no schematic.

Hello All,

I am in need of a new replacement motor and speed controller to replace the stock motor/spc on a vintage Thorens TD125. Premotec and Maxon were both motors I have heard good things about but I have no idea which model would be most suitable and how to go about purchasing/building a speed controller and power supply. I am not interested in the Origin Live motor option as I feel there may be a better solution through purchasing separate high quality parts directly from the mfg. I do not wish to simply replace the stock TD125 motor with another vintage unit as I feel the table is worthy of a much higher quality motor. Ideally, the motor would rest in the same location as the original one within the subchassis with the belt riding on the outside of the inner sub platter. I was not sure if this also played a factor when trying to find a suitable motor but thought I would mention it anyway. My thoughts were the power supply and speed controller would be outboard placement wise, so would not have to worry about fitting inside the chassis or plinth frame.

It would be ideal not to have to mess with the original power supply or internal electrolytic caps, ect. I would much rather go new all the way. 🙂

Thanks,
Chris

Hello all, I'm interested in the quadrupole design from Mark Audio site:

https://www.markaudio.com/wp-content/uploads/2022/08/Alpair-11MS-linear-quadrupole.png

I'm thinking of making them bipole (two front / two back) instead of four-sided mounting. Please share your thought about this. Thanks 🙂

I renamed bluetooth 3031 with qcc tool it crashed and then I power on bluetooth the phone doesn't see it anymore. I need some help. thanks a lot. I also tried using MDE to deloy fw and when connected no sound source came out.

Anyone tried this?

A friend who runs an independent gift shop in my town has shown some interest in selling some speakers I've made as a hobby. The first thing I thought was I wouldn't sell enough to justify the costs for lab testing for EC compliance so it is a non-starter. I've been googling but can not find an answer to what directive passive speakers fall under if any. Does anyone have any information on this?

Best SVS Subwoofer for music?

According to attached TL alignment regarding tapered transmission line Figure 1 : Classic Transmission Line Geometries first option where is SO>SL.
What is suggested SO ratio compare to Sd (surface driver).

Hi folks!

Hoping somebody can help me to fix up my Akai AA-1020 which has been (hopefully temporarily) put out of action due to my own stupidity!

The amp had been recapped recently, adjusted, and was working beautifully. Sounded lovely. The only problem was the old headphone socket was cracked and resulted in intermittent connection with the jack inserted. Fortunately I sourced another that was an extremely close match. Did a test fit of the new socket to make sure… and forgot I'd left it there... loose! Yep (slaps forehead!).

Had just turned off the power (thankfully, or it might have been worse) after a listening session, and the socket decided to fall into the internals at that point, creating a spark and there was a loud pop. As I said the power was off, so it was either residual charge left in the reservoir cap, or from touching the live terminals of the on/off switch (probably the most likely). Obviously there must have been some short. The spark was large enough to burn off a corner of one of the solder tags on the new headphone socket as it fell to the chassis base!

Whenever the amp is turned on now, R16b (150R) starts smoking almost immediately. Replaced it with a new one and the same result, so obviously I've really screwed something up. This is alas out of my league really, so was hoping somebody might be able to look at the circuit diagram's below, and the PCB layout (smoking resistor circled in green) and spot a potential component to check and change. I'm hoping the transistors haven't blown from that short, but sod's law being what it is I'm guessing that's what's happened.

I can’t take any voltage readings on the amp board at the moment as that resistor starts heating up immediately. Have checked for any obvious burn marks on all PCBs (there aren’t) and there’s no sign of any blown components, at least not visually.

Main PSU and Amp PCB circuit (rest of the circuit not shown is for tone control and RIAA boards):



Amplifier Board:



What it looks like for real:



Where to start?

Any help would be very gratefully received 🙂

Thanks.

- John

"B x l," also known as "Force Factor," is one of the canonical Thiele-Small Parameters.

As explained in the linked-to paper, Jim Tuomy and I believed that a new Parameter, complementary to and analogous to Force Factor, would be helpful. We call that new Parameter "Load Factor."

Then, when one expresses the relationship between Force Factor and Load Factor, we call that result the Agility Factor.

Load Factor and Agility Factor are “Quick and Dirty” methods to quantify what an experienced designer might in any case be able to intuit from scanning the data sheets on two different drivers.

No more; but certainly nothing less.

A comparison to the well-accepted parameter Force Factor (B x l) illuminates. Force Factor has no need of complexity. Force Factor has no need of calculus, the symbol Pi, or constants. It would be very difficult to have fewer “moving parts” than does Force Factor.

Force Factor relates a physical characteristic (voice-coil length) to an electromagnetic phenomenon (flux density) by the simple arithmetic operation of multiplication.

Load Factor is analogous and complementary to Force Factor. Load Factor is merely an expression of density rather than mass.

In much the same way as Force Factor is derived, Agility Factor relates a physical characteristic (cone density) to an electromagnetic phenomenon (Force Factor). Except, in this case, the simple arithmetic operation is division.

Looking at the Table of drivers under consideration, it is almost impossible to escape the conclusion that the woofer-mid with an Agility Factor of 71.96 is more Agile (or, more responsive; or, just plain better at starting and stopping) than the woofer-mid with an Agility Factor of 26.78.

We believe that the burden is on the naysayers to prove that the above conclusion is illusory.

https://positive-feedback.com/audio...proposed-additions-to-the-thiele-small-canon/

john

Dear All,

Did anybody use the new Muses 72323 ? I am testing a board, but I cannot get the chip to work.
I tested the controller with the Muses 72320 and it works perfectly. The Muses 72323 has the Clock in and I did not really understand what should I do with it.

Regards,

Davide

Many years ago I implemented John Swenson's voltage regulator in a tube amplifier. I saved the gerber files for the pcb on my laptop....which is long gone..
I need the gerber file to make a few new boards. Maybe someone has this file and is willing to share it ?

best regards Vegard

Hi all, I really didn't know whether to post this new thread or post this in the original thread I started from 9 years ago https://www.diyaudio.com/community/threads/gibson-ga-8t-tremolo-fault.239662/ (mods, if you feel it should be moved, please do so).

This will be lengthy and I sincerely apologize........

I built this circuit with parts I had on hand, As I didn't have a 5Y3 rectifier and PT at that time I installed a 6V4 rectifier & PT I pulled from an old radiogram.

Two nights ago, I pulled the amp out of long term storage and fired it up to discover no sound/nothing except for the heaters which were working fine, I checked the voltages at the rectifier B+ and discovered the first dropped resistor 250ohm 5watt had blown, I replaced the resistor, powered back on and all went well for a few minutes, I then noticed the 6V4 was glowing an unusual red colour and then I heard a small pop, The resistor I had replaced also blew.

So I made a decision to replace the 6V4 for a SS rectifier, 250ohm resistor changed to 330ohm 5watt (knowing I would slightly have higher B+ with the SS rectifier)

A careful voltage check after installing an SS rectifier is as follows,

B+ at rectifier surges to 374v then settles to 297v.

B+ after first dropper resistor surges to around 360v then settles to 270v


V1 pin 1 - 204v
2 - 0
3 - 2.6v
6 - 140v
7 - 0
8 - 1v
9 - 0

V2 6BM8 pin 1 - 31v
2 - 18v
3 - 0
6 - 262v
7 - 255v
8 - 51v
9 - 162v

V3 6BM8 pin 1 - 0
2- 18v
3 - 0
6 - 260v
7 - 257v
8 - 1.5v
9 - 108v

The voltages seem in the ball park, compared to the original circuit values here https://schematicheaven.net/m-gibson.html However, should be worried?

I also mentioned the 6BM8 in V2 socket/position was red plating, So I swapped that into V3 position and the red plating followed, I'm thinking this is possibly a bad tube?

The PT secondary HT for the circuit is 260-0-260vac.

I do appreciate the time taken to read this and hoping for advice.

cheers Ron

Looking for at least one THAT Corporation 1206 line receiver chip. I prefer the DIP-8 package but will consider SOIC as well. Thanks

Hi all, someone was kind enough to share this model with me and how to use it and being very new with the program, I am having trouble understanding the process

I have done the tutorial on introducing a new model, but cant see how to use this text data below in the tutorial steps. I would like to request someone show me how to use this information to enable a triode symbol on the LTspice work area in a mini tutorial please

Thanks and regards
Randy

*

• Generic triode model: 5670_AN
• Copyright 2003--2008 by Ayumi Nakabayashi, All rights reserved.
• Version 3.10, Generated on Wed Nov 29 08:47:18 2017
• Anode
• | Grid
• | | Cathode
• | | |

.SUBCKT 5670_AN A G K
.PARAM X1=-0.044770209 X2=0.032175849 X3=-2.2476294
.PARAM X4=0.40025303 X5=18.639663 X6=3.7476294
.PARAM X7=0.0040093865 X8=46.569699 X9=0.0099503146
.PARAM Y1=0.0020046932 Y2=0.0021345255
BK IK 0 V=U(V(G,K)+X1)X7*URAMP(V(G,K)+X1+URAMP(V(A,K))/X8)^1.5+(1-U(V(G,K)+X1))*X9(X2*URAMP(V(A,K)))^X3*(X4*URAMP(V(G,K)+X1+URAMP(V(A,K))/X5))^X6
BA A K I=URAMP((Y2*URAMP(V(A,K))^1.5)-URAMP((Y2*URAMP(V(A,K))^1.5)-V(IK)+Y1*URAMP(V(G,K))^1.5*(URAMP(V(G,K))/(URAMP(V(A,K))+URAMP(V(G,K)))*1.2+.4)))+1E-10*V(A,K)
BG G K I=Y1*URAMP(V(G,K))^1.5*(URAMP(V(G,K))/(URAMP(V(A,K))+URAMP(V(G,K)))*1.2+.4)
* CAPS
CGA G A 1.1p

How much volume do I need at least for 2x 12 inch drivers to get down to 10 Hz and how far can DSP help me?

Power supply

Is there a way to drop the 260v output to 160v on the above linked power supply?

Thanks and regards
Randy

Hi,
everybody this is sekhar from INDIA (WB). This thread is dedicated to our great "Dr Bora" also known as "boraomega" in the forum .This thread is specifically dedicated to the great amps built by "Dr Bora".
It is a salute to his great contribution to the diyers . It is welcome note to all the people who has already built his amps or willing to built his amp .it will be a common platform for all the fans of Dr Bora & his amps.
I personally have made two of his amps
1. LEGEND STAGE MKII
2. STUDIO SE
Both of the amps r a master piece in it self .
Every body who has built Dr Bora's amps r requested to post their reviews and pictures .
their r many amps in this this forum that r liked and built by many diyers .Dr bora's amps does nt seem to be one of them as they r nt brought in light to the diyers . I will try my best to provide all the details of the amps built by dr bora of course with his due permission.
for a start I will provide the list of amps by dr bora.
1. CALOR- gold(CLASS A 40W)
2. Standard (50-60W RMS/8 ohm)
3. Lambda (100W RMS/8 ohm)
4. Legend(125W/8 ohm)
a.LEGEND-Stage Master(250W RMS/8 ohm )
b.LEGEND-Stage Master MK2(500W RMS/8 ohm)
c.LEGEND-QUASOR(1000W RMS/4 ohm)
5.Modus (aka Techno)
6.DOGC-MK3
7.Studio
8.STUDIO SE(80E RMS/8 ohm)
9.Epsilon(100-120W RMS/8 ohm)
10.Sigma
11.SubZero
12.CroSer( 100W RMS/8 ohm)
13.T-Reference
14.Goliath
15.Universal
16.Blaster

ALL OF THEM R VERY GOOD AMPS NO BODY HAS PUT SO MUCH EFFORT FOR DIYERS . HATS OF TO U DR BORA .
WILL PROVIDE MORE DETAIL LATER .....
DR BORA'S WEBSITE :- bas.elitesecurity.org

REGARDS
SEKHAR

SOME OF DR BORA'S AMPS BUILT BY ME :-

Anyone have any ideas for projects for these modules(9)I bought years ago from ApexJr? Just found them up in the attic, look like high quality but weird cross over freqs and power supply requirements for the different amp modules.

I'd be most grateful if anybody here could provide a copy of the 5AR4 power supply schematic for Poindexter's Musical Machine. The web is rife with the sand version, but the "new and improved" schematic seems to be lost to the sands of time (and yes, I've already searched this forum). The Wayback Machine has numerous references to his old site, but many of the schematics are missing - including that one.

And while I'm thinking of it: was there ever a specific schematic for the 6V6/6GK5 version of the MM, or was the builder just supposed to take the 6GK5 stage from the EL34 PP schematic?

Enquiring minds want to know... 😀

Hello,
I have a little question about port calculations.
I wanted to design a subwoofer box for two 12’’ speaker and wanted to make it look like the ks28 from L-acoustics but they use what they call “L-vents” (first picture) that are curved and I don’t know which measure to use for the vent surface in software like winISD.
Do I have to use 340mm or 140mm or something else (second picture) ?

Thanks for your help 🙂

I was going through a box of old parts and found two bags of (I think) TO-18 package transistors, one labeled "NPN", the other "PNP".

Looking at what's in the bags, I see the printing on the NPN transistors says SS5928-1 312, with the Motorola logo.

The PNP transistors say SS5929 7224, also with the Motorola logo.



I googled around for data sheets or specs and couldn't find anything. These devices must have gone obsolete before the internet happened. I found a 2N5929 and a C5929, but they're nothing like these.

Would anyone happen to know what these are?

Hello guys

Long story so I will cut it so you at least feel my pain..18 months ago a purchased 2 bk electronics monoliths and I wasn't overly impressed so after watching many YouTube videos I decided to build 2 subs. So I purchased 2 dayton um18 22 and 2 sa1000 amps.

The boxes I made are

600mm wide
700mm high
700mm deep
External measurements
18mm x2 mdf all round so each panel is
36mm
Furniture foam inside on all sides

When I set it all up they sounded and measured exactly the same as monoliths. I knew this was impossible and I must have an issue. After four exhausting days of fault finding I found a audio enhancement setting on the TV but not in TV settings!! This setting was only visible when I went into the TV through my lap top!! Now the monoliths sound awesome 👌 and I wish I purchased two more at £1400
I'm now £1700 in with the dayton build and they don't sound know where near as good as the bk monoliths! They are punchy and lack extension below 30hz. Infact they only sound good and really loud from 27-40hz But I think they could come good if I add two passive rads to each box

Il be £2400 in by then!! What do you think guys? Are passives the answer? Or new boxes? I was hoping to build monsters but all I've done is put put a monster hole in my bank account!! I'm gutted 😢 😞

I've just ordered a Cambridge 2 channel amp aswell. It's getting out of hand guys! I want to get it right so I just enjoy it instead of obsessing. Big room 4 subs 1 in each corner.

Hello,
I have a pair of Definitive Technology BP2000TLs that use 75ohm 15” subwoofer drivers and 500watt amps. The built in amps have finally died and the place I sent them too for repair said they can’t repair them. My guess is because of the 75ohm load. Anyways, I have a few question

1) I’d really like to fix the original amps. Does anyone know where I might be able to get them repaired. I’d really love to keep them as original as possible since I have always love how these speakers sound!

2) I completely understand that an amp is going to be putting out only a fraction of its rated power at 75ohms, but if I put enough power to them with they still perform. I kinda tested this theory using one of my Onkyo M-501s that are only 150w a channel. At a moderate volume and enough gain they do sound good. Anything beyond that and the amp just doesn’t have output to keep up. I was thinking of maybe using a D-class amp module, and modifying it to fix, but how big would I have to go for it to perform close to the original 500w amp?

3) if #2 is an unreasonable option, then I need to find a reasonably priced 15” 4 or 8ohm sub that will perform well in about 2.8 cft. enclosure with a port that’s 1.5” x 7”x 14”. I don’t have modeling software so any help here would be greatly appreciated!

Thank you in advance!

Hi all!

It seems a very interesting driver, so bought a pair of them in the 8ohm version.

Faital Pro 10RS350 10" Bass Speakers - Faital Pro 10RS350 10" speaker for bass guitar. - Faital Pro 10RS350 600 watt 10" bass guitar speaker for all high power bass applications. Faital Pro 10RS350

My plan is to put them in a pair of small vented boxes (around 1cubic feet/30 liters tuned to 40-42Hz)

What I didnt notice is the high Le (1mH) so Im not sure if it would work with a 1" comp driver. Crossed around 1-1,5k

I want to avoid the 3 way option.

Do you think guys it would work?

Thanks!

Hello,

You know, fungi like place without light and subwoofer enclosure is a very good place for this living organism. If we consider that at some sobwoofer we also add textile or metallic grill the environment became even better for then to grow.

It's also important to mention that some guys may live in a very humid country or place witch will make this issue even worse.

Due to the covid situation and having my loudspeakers stored for too long time and found is issue at my drivers, probably it happen not only to me, so, how do you guys handle mold/mould in the subwoofer driver?

Someone knows if they can generate permanent damage or if they can affect the drivers parameter in a significant way? mainly at the spider (driver suspension).

Rust is very common and will affect all the driver soon or later regarding the quality of the coating/paint used in the production process, but it's more visual issue, but mold I'm not much used to see it.

Note.: I made a gig yesterday as it's and the sound quality was not affected yet but today I clean up with lysoform Spray so I hope I was able to kill them for a good period of time and the product don't degrade the spider or the cone due to chemical interaction.

My build could benefit from a nice curved port! I didn't see any curved 3.5" 19.75" ports though, does anyone know of a good source for something like this or should I just make my own out of angled wood with 8 sections or something? Thoughts?

Hello,

I am packing up and moving.

There are too many speakers, some all original, others recones with OEM parts and others are Frankenstein speakers made with voice coils from one model cones from another model voice coil and frames from another. I have one set of 15 inch Frankenstein JBL’s that are near 2235’s maybe.

What I want to do in this thread is measure speaker stuff starting with Thiele Small parameters of the 15 inch Frankenstein JBL’s.

This is just for fun. I have the time and space plus new to me Audio Precision APx1701 speaker measuring tools.

I am going to start by attaching the Frankenstein drivers to a fiberglass ladder to measure the Thiele Small parameters. I am thinking of using the added weight method as opposed to the known volume box to do the measurements.

Anyone with thoughts to add?

Thanks DT

I have 1 lonely Altec 420a biflex. It’s got a low serial number (~1100) so it’s the 15” version. It’s in great shape.

I’m looking to acquire a sister early 420a (15”) but I would consider selling it if I can’t find a suitable match….. so any sellers, buyers or if you know where I might find one please let me know 🙂

But I'm not buying.
I just bought a NOS Behringer XO from eBay and I was looking at the sellers other items.
Among the stuff for sale were some speakers and this was amongst them. I'd never heard of them but others may have and care to comment on them.
One of the speakers for sale is from Phase Linear
Andromeda 3; a relatively large OB speaker with multiple drivers and multiple orientations.

"Coming soon" on the Infineon site. These look interesting for battery-powered applications.

Product brief:
https://www.infineon.com/cms/en/product/promopages/merus-multilevel-class-d-ma2304xn/

Chip:
https://www.infineon.com/cms/en/pro...grated-class-d-audio-amplifier-ics/ma2304dns/

Eval board:
https://www.infineon.com/cms/en/product/evaluation-boards/eval_audio_ma2304dns/

I stumbled across these while trying to work out whether I wanted to have a play with making something based on the MA12070P using an ESP32 for DSP, however the thing that appeals to me with the MA2304DNS (apart from low quiescent current) is the onboard DSP. Seems it might be a nice way to minimise part count while also allowing for fairly modular / flexible speaker configurations.

There's also a MA2304PNS version that drops the DSP, not sure whether there are any other differences between the two.

I haven't done any sums, but if I'm reading the data sheet correctly, the quoted efficiency improvements seem to be "at typical duty cycle for full range music" and probably wouldn't be quite as impressive if playing sub.

The "PCB as heatsink" approach described in the PDF for the eval board is interesting, but I think I'd want to go for a heatsink for my use case (portable boombox). The size/weight of the amp plus heatsink will be a drop in the ocean compared to the cabinet, driver and battery - and based on the thermals it looks like a heatsink would be useful if I end up with a 4ohm load.

Looking for at least one THAT Corporation 1206 line receiver chip. I prefer the DIP-8 package but will consider SOIC as well. Thanks

The maximum sustained power draw for the heater supply in my build is 2.16A, and for the B+ supply it's 90mA. What is an appropriate fuse value for these two? They are already factored above expected power draw by 1.8x. Would 2.25A and 100mA be appropriate?

Then my next question is, should they be slow or fast blow? I assume slow-blow since they are power supply and not line fuses?

I'm selling a pair of "open box" Lundahl LL1660S/10ma Tube Amplifier Phase Splitting Interstage Transformer.

They have been wired for ALT B. but I can remove the wires if desired.

They are in very good condition. They have not been powered on. I have bought them by mistake as they don't fit the amp build I'm working on. sigh...

I'm asking $150 plus shipping of a 4lbs. package from 11105

Thanks!

Looking at the datasheet for the CL series thermistors https://www.mouser.com/datasheet/2/18/AAS-920-325D-Thermometrics-NTC-Inrush-031814-web-1315885.pdf it shows the thermistor being placed between the rectifier and the filter cap. Is there any issue placing it in with the transformer primary?