diyAudio

studeb · 2022-09-10 3:09 am

I have a P300 that blew the main supply caps. Does anyone have a schematic for this beast? I am trying to figure what grade caps to replace them with.

Thanks for any pointers.

BadgerMcBadger · 2022-09-10 6:14 pm

starting price of 140eu. willing to negotiate

Bigman80 · 2022-09-10 6:09 pm

Hi all,

I bought this case a few months back with the intention of building a preamp into it, however, i ended up going in a different direction. I have just got it out of storage to measure up for another build but it doesn't fit in, or on my rack lol.

I paid around £150 for this at the time, and checking today they are still around the same money.

It is immaculate, never used and 100% complete. All knobs and fixtures are included. The AliExpress listing is here:

https://www.aliexpress.com/item/100...00015850022162!sea&curPageLogUid=szucoTFThnQ9

Dimensions:L480*W358*H80 MM

Internal dimensions: L468*347*H74MM

Thickness of each part: the first 8 and the last 3 or so 4mm

I'll accept £85 delivered in the UK

kcin · 2020-03-09 3:01 am

Hello

I read some inspiration here about some Counterpoint SA 3.1 and 5.1 mods and repairs.

I had a chance to pick up a 3.1 and although I did not need it, it reminded me of some of the Counterpoint gear I had in the 80s. I love the form factor.

The object was to totally mod the power supply. Isolate the stock B+ and filament supply and replace it with a tube rectified , series pass with voltage reference and a separated heater supply.

The size comparison of the old transformer box to the new reg is comical.

This was meant to be an all out assault with no practical sense as all it took was money and time.

5AR4 rectifier, OB3 voltage reference, 12au7 error amp and el84 pass

After a few months of collecting parts and working part time at it ... It finally came together and is testing well

I added a pair of sowter step ups as well for MC and it is switchable for 1:10 and 1;20

Everything is totally reversible. Sounds Sweet ... better than the 5.1 I had .

New coupling caps, audio note sockets, TKD pot and balance, RCAs, solens for decoupling etc..

Hopefully this will inspire some one else. I don't usually take on projects like this but I thought the SA 3.1 would benefit and I would have some fun-- time to burn it in and have some fun with it.

mbrennwa · 2022-09-09 8:03 pm

A few days (weeks?) ago, the display of the list of posts has changed. Instead of showing only the titles and authors of the posts, there is now also a preview of the posts showing text and maybe even some graphical stuff.

Questions (and rants) about this:

Why was this introduced? I don't like it.
The previews take up a lot of space, so I typically only see about one or two posts on my screen, and I have to scroll a lot to see more posts in the list. Before the change, the screen area was used much more efficiently to show about 10 posts, so much less scrolling was needed.
The previews are not always there. For example, I do get the previews here, but not here. Why?
I looked in the settings / preferences of my user account, but could not find anything to change this back to how it worked before. How on earth can I turn off the previews?

Michael Marmaras · 2022-09-10 3:03 am

New post wanted info about Dayton PS 95 3.5" driver for a horn application. I bought one to try in a small 3.5 foot Voigt homebuilt. Had B3N Hi Vi. They were from another project and they livened up in the transmission design.really open airy for puny speakers. Bass was of course not low but pretty accurate.top end was not there but cheap super tweeter would fill in with out any problems. Sorry back to the ps They are THE BANG FOR THE BUCK driver. Perfect for bedroom or small den. Inexpensive too. What more do you want. No phase issues x-overs cost and complications.

mrjayviper · 2022-09-10 4:08 pm

I need .200 ohms to be placed at the output of a power opamp(lm3886)

I'm thinking of paralleling 5x 1ohm 0.6w metal film to get the desired resistance. Thoughts?

Thanks for the help.

Edit: forgot to mention that all the resistors are of 1% tolerance.

This is a sample schematic of the amp.

Ian527890 · 2022-07-06 4:45 pm

So . ...

I have built a little stereo pcl82 amp simple open ended.

It's running off a 240ac to 24dc converter with a buck up converter to obtain 170dc smoothed by a 20w 380ohm resistor and two 100uf capacitors.

I have added a 910M resistor and 1.8uf capacitor in high pass config in place of the volume pot to avoid amplifying anything below 100hz

I am hearing a hum.

Using my phone and an app it seems to be 183hz

Is there anything obvious I should look for?

io · 2022-09-08 4:54 pm

Hi
I need some help with identification.
Short plate, frame grid, three mica,
a27 on the lower glass,
Balanced within 1%
Sure original rare siemens E83Cc?

io

andyjevans · 2022-09-08 9:00 pm

I have several aluminium chassis top plates for amplifier projects where I've drilled holes in the wrong place and want to fill them up to give an aluminium finish and disguise the hole. Ideally I just want a tube of something that looks kind of silver so I don't have the bother of mixing epoxy. These are just 3mm or 4mm holes. No strength required. Like equivalent of plastic wood, but with a metal finish.

So what cheap and easy products can I use? I'm in UK so should be available here - e.g. well-known brands should be widely available.

I found some CTI sealant in a silver colour - something like that?

https://www.ebay.co.uk/itm/29511895...KPoBJ9kIizYOQpCtGrZtv2RViW5R|tkp:BFBMyoCi6-Ng

.

Fabianmu · 2022-08-09 1:57 pm

Hi everyone,

I'm looking for a DAC IC that is easy to integrate into a new USB DSP board design.
I would choose the IC based on the following criteria:

Easy to integrate: keeping the external components at a minimum.
1. If possible include Opamps and Filter in the package
2. preferably SOP or QFP package
Robust design
I2S and/or SPI interface
2 or 4 channel design. planned is 2xBTL input at the Amp.
moderate price: I don't want to spend more than 30 € for the DAC including external components.
It should support 16-bit 44.1 Khz minimum.

Any recommendations?

Best Fabian

pantoro · 2022-09-10 2:28 pm

Hi! i have purchased an AMCRON PSA-2 with the balanced input card.

Signal are eletronically balanced, and i would balanced them with audio transformer (es. LUNDAHL LL1539)

I can take the signal, make it pass through the transformers and then insert it directly into the circuit, Bypassing the board.
Is there another way?
I hope you can help me

NickKUK · 2022-09-10 9:50 am

Login to view embedded media
Well worth watching. It shows the best concept for low noise power supply without letting noise through.

ajmartin · 2022-09-09 1:19 pm

I am wondering if anyone can recommend a good assortment of resistor values to start stocking a workbench for tube experiments. Looking for info such as 1R to 10M 1/2W or will I need an assortment of 1W also? I already have pretty much every value 1/4 W both 5% and 1% . I also have an assortment of Caps, but most are low voltage as I am mostly a Micro-controller designer. I do own a Dynaco ST70 and a Supper PAS3 for a long time , so am a tube lover.

Alan

merlin el mago · 2012-12-08 2:00 pm

I want to build The Optimized Morgan Jones Amplifier but I have question about output cap beacuse I want to use film instead lytic: the schematic uses 470uF 350V, really is necessary so big or I can use a small film cap like 27uf or 10uF or less?

An externally hosted image should be here but it was not working when we last tested it.

limono · 2022-08-25 5:05 pm

They can be older "magnetic" types as well, as long as they are 1W or two wats

680 Ohm-8
1K -6
2.7k-2
15k-2

If you less , then required quantity I will take what you have. Resistors can be used but have to measure OK and the leads should be still long enough to mount on PCB. TIA. L

saptemari · 2022-09-10 12:26 pm

Hello everyone,

Please help me with at least one noval tube socket like the one in the pictures; I've got only three and I need four.

Thank you!

rwij · 2022-09-10 4:46 am

Can anyone identify this preamp?
Rhyme on the front panel is the only label.
It uses 6J1 and 6P1 tubes.
I purchased this years ago, and I’m curious what it’s worth.

BallastBoy · 2022-09-10 9:33 am

Does anyone have these available for shipping to UK?
I have seen a couple of previous posts but they look like they have closed.
Thank you.

emtor · 2022-01-29 8:25 am

It's been decades since I fiddled around with tube amp building.
In those days polyprop caps in a PSU was unheard of and beyond anyone's imagination unless you wanted to use a million of them in paralell.
In today's day and age high voltage/capacitance polyprop caps are common and I've managed to find 47uF/630 volt Solen caps at thetubestore.com.
But,-are there other places (preferably in Europe or the UK) where these can be found?

bungonokami · 2022-08-06 12:22 am

Hi, sorry for posting a newbie question...

I'm buying a used portable PA system package (Fender Passport PD-150 - similar to the one shown in this video), but it's missing the two accessory speaker cables.

I've soldered a couple of guitar cables before, so I'm thinking I could buy speaker cable wires and connectors on Amazon and try to make replacement speaker cables for the PA system myself.

So I've found connectors like these and speaker wires like this one. Will these work for the above-mentioned PA system?

I'm assuming TS is the connection type, not TRS, correct?

Is a speaker patch cable soldered the same way as a guitar cable?

I see that the wires have "AWG" ratings, I don't know what this means, but should I go for above certain rating for live sound use?
Perhaps home audio systems use different ratings?

These are probably very basic questions to you, but if anyone would be kind enough to enlighten me, I'd appreciate it! 🙂

jororaitchev · 2016-08-31 11:48 am

Hello,
A model of my DIY loudspeakers i have served Ti6k- JBL. My first contact with
them, was in distant 2005.
I started working with them in 2009 and finished in 2012.
The loudspeakers are "SEAS"- Excel / Tw-1”, Mw-5”for center 2х 5.5”,Bass-8,5”/ and cross-over parts- "Intertechnik".
Have are some pictures, if there is interest, i will continue.
Regards!
Joro

doofdoof · 2022-09-10 8:12 am

Good day,

I’m looking at rebuilding a REL subwoofer with busted driver and amplifier.
My plan is to rebuild the sub with similar or better spec as original.
Comparing the specs, it looks like I can achieve 33.6Hz at -6dB vs factory 21Hz at -6dB, and still 60W short on power...
https://rel.net/shop/powered-subwoofers/s3/

I have the subwoofer enclosure with 12” Passive Radiator.

I’ve purchased a 10” Peerless subwoofer rated at 300W at 6 ohms.

Now I’m checking if the driver will fit the box and contemplating on which plate amplifier to purchase in Australia.

Subwoofer Box size

40 x 35 x 38 cm OR

15.74 x 13.78 x 14.86 inches

Thickness: 3.5cm OR 1.38 inch

Volume: 31.55 litres

Peerless 10” Subwoofer: See attached specifications

12” Carbon Passive radiator: Spec unknown

Power amplifier calculator using Dayton Audio SPA500DSP plate (not purchased yet)

4 ohm – 500W

6 ohm – estimated 333W

I’ll need to put a blanking plate on the rear of the subwoofer before I mount any plate amplifier.
I've attach some screenshot of the results from WinISD as well as the project.

Any advice on the choice of amplifier or the suitability of the driver will be much appreciated.

Thanks in advance.

Tom

lecriquet · 2022-09-02 9:12 pm

Hello everyone 🙂,
I have a pair of DIY column whose design is attributed to Mr. Troels Gravesen and the realization to myself.
The project: CA18RNX floorstander
The measurement :

I will take the measurements at home when I have a UMIK, but we can think that they go down to 150Hz or even 100Hz in the range +/- 5db
I want to add a sub to have an extension in the bass (20Hz would be cool).
I mainly use my system in HiFi, no nightclub. I enjoy listening to music, but not at unreasonable levels. I am nevertheless in a house without adjoining neighbor, so I can push the level if I want to.
The installation is in a living room of +/-130m3, and my couch is approximately at 2.5m from speakers.
I have space for a 150L box (minus wood, speaker, etc... the box can be 60*50*50cm outside).
It will be powered by a Behringer a800, measured by Amir
Nevertheless, if the amp is limiting, it could be swapped.
I played around a bit with Dominique Pétoin website and loudspeakerdatabase. One particuar subwoofer hold my attention: the DAYTON RSS315HFA-8
Surprisingly, Dominique's website gives me a simulation, but only with events that are much too long...
Wininsd does better.

These simulations give me, if I do not misinterpret, an f3 at 19Hz and SPL at 3m/100W of 95db up to 30Hz.
That would be just perfect for my needs.
But ...
I think it's too good to be true, so I'm coming to see what you think?

Thanks for the help
Alex

escksu · 2022-09-07 3:36 am

I saw a few brands like vtv selling it but it's completely missing from purifi's website. I did manage to find data sheets on it but not from purifi.

So I am puzzled what happened to it.

Dr Zeus · 2022-09-10 3:38 am

25 year old Class D amp. Love the sync design.

Output transistors are precisely IRF530N & IRF9530-nonN. So a MIX of N and Non-N outputs. I dont have any 530/9530 anything. I DO have IRF540N/9540N and also IRF540/9540 Non-N. I also have IRF3710/N, and IRF640/9640 in N and non-N.

Are any of these decent subs for the IRF530N/9530 factory mismatched outputs?

Thank you

crowmo · 2022-05-26 2:39 pm

Hello everybody,

I read in an old google groups thread that it is possible to use, say, 2 taps from the OT at the same time (ask if you want the link). For instance, a OT with 16 and 8 ohm taps can be safely and correctly used if a 32 ohm speaker is connected to the 16 ohm tap, and 16 ohm speaker connected to the 8 ohm tap.

I'm not 100% convinced that it is safe and correct because of some qualifying remarks in the thread but generally it seems to suggest it is ok. So, is it safe and correct usage?

If yes, is it possible to implement a simple attenuator by replacing the 32 ohm speaker in the above example with a, say, 50w 50 ohm rheostat set at approx 40 ohms? This would be a simple way to get attenuation but would it also avoid all the tonal changes (ie "tone suck" but not the SPL psychoacoustics) associated with attenuators?

Thanks in advance for any all comments.

squarewave · 2022-09-10 2:44 am

I'm upgrading a class ab amp ( from active 2 way monitors- event opals) that has some caps in the signal path

* see attached schematic- output goes to input of first stage of amp

1.0uf 63v film cap for tweeter

100uf 25v non polar/ bi polar electrolytic cap for woofer

and also, in parallel with the 100uf, a 0.1uf 250v film cap for woofer

the oem caps are all around 10 years old, and all no name/ low grade

with a small budget, and very limited physical space to mount caps, what caps should i consider that may provide smooth and
clear highs (metal dome seas), and smooth and clear mids and lows ?

in my inventory, that im considering using, i have some 1.0 uf multicaps ( ppfxs, ppmfx, ppmf), nichicon fg 100uf (polar), nichicon 100uf es (bipolar),
and 0.1 uf film caps ( small blue cubes, * possibly mkp 1837 vishay ?)

tizman · 2022-09-07 4:51 am

Hi All! I’m in the final stages of an Aleph J build and have a question about the mosfets I purchased (a very long time ago) from Jim’s Audio on eBay. I have attached some photos of the eBay ad text and of the actual mosfets for your consideration. Are these mosfets well enough matched for my build, or should I buy a new set from the DIY Audio store? I’m mostly a tube guy, and I don’t understand how the Jim’s Audio ones I have compare to the DIY Audio store’s sets. I have also attached a photo of the DIY Audio store’s description of their mosfets for your consideration. Any guidance and advice would be much appreciated.

Jim’s Audio description

Jim’s Audio mosfets

From the DIY Audio Store

My Aleph J

eightdigitword · 2020-04-30 9:05 pm

hey,

I have a load of 'NAIM' NA009 transistors I say 'Naim' cos they are marked with this but there is no way they made them. I have 24 PNP and only 2 NPN. I bought an electronics factory job lot off ebay a while back and these were in there.

obvs know a bit about electronics but not enough to know this!

question is, what can i do with them (other than sell them)? I like messing with electronics and learning as i go. I thought id throw this out here to see what comes back.

am i right in saying class A is possible with NPN only, but a waste of time these days?

one or two amps using the pairs for A/B?

next question, can the specs be measured or determined? 80A and 350W is mentioned in naim pamphlets of the time. nothing else.

would this all be a waste of time and using known chips would make more sense anyway for an in-audible difference???

can these be retro fitted to Niam NAP models of same rail voltages as the NAP 300 / 500. provided the voltages are the same, pin outs changed to suit and adequate heatsink could these be used as drop in on other amps?

any/all thoughts most welcome

Ta

elwood625 · 2022-09-09 2:16 am

I have a 0 -30 vdc lab power supply which will produce +- 15 vdc as a Bi-polar supply. It is nice as a beginner tool, now I would like to buy a Lab Supply that will give a +- 24 vdc as a minimum and +- 36 vdc would be nice, just not sure how often I would need that much voltage. I can find 0 - 60 vdc models of my current supply, but I would like a better quality supply. Something I can trust to work and be accurate and somewhat clean of noise. I'm willing to spend up to $300 for a quality tool.

Any suggestions?

kd4ylq · 2022-09-10 12:20 am

Want to buy (or trade for) a Pass/Sony VFET amplifier. Unbuilt with black chassis preferred. I use a First Watt SIT3 in my main system with Spatial M3s and it's a great match. The Pass Sony VFET should have similar sound quality albeit at a much lower power level but that's OK with me. Have an excellent condition pair of Marantz Ma-5s to trade (230 VAC). I used them back when I had electrostatics and needed a lot of low Z power. They are still in my second system, but now I use high efficiency Lii speakers and even with the MA-5's set for Class A operation 30 watts is ~20X more power than I need! (they do make a lot of heat in Class A, but a lot less in AB, which is what I normally use). Have the owner and service manual, but not the original boxes or packing materials. Let me know if you have changed you mind on the Pass VFET amp for any reason and are considering letting it go. Maybe we can both come out ahead. Thanks for reading and happy listening!

Jim de kd4ylq

Stlhooper · 2022-09-09 3:11 pm

My circa 1994 Klipsch CF1 floorstanding speakers have crossover boards which contain a couple of electrolytic caps which have values that I’m unable to find replacements for.
Specifically:
Markings show T.I. Which I believe is Tecante. Mmmm beer.
28MFD +/- 5% 100v
40MFD +/- 5% 100v
I suspect these were custom made for Klipsch. (Sigh)

I’m out of my realm as it concerns electronic circuit behavior so please forgive if I’m being naive but I’ve read that as electrolytics age they morph and introduce an unintended amount of resistance. Is that a quality that can be measured with a modern Fluke dvm?
I do not have a schematic.

Much obliged.

east electronics · 2022-09-08 4:04 pm

Got acouple of those bins are imitasion local made
i will attemtp to use them with a lavoce woofer

LAVOCE WAF153.00 15" WOOFER

woofer specs ar here http://www.loudspeakerdatabase.com/LaVoce/WAF153.00

do you think that i can make a usable result out of them ?

limono · 2022-09-09 11:23 pm

Leads need to be fairly long.

LectroMoto · 2022-09-09 1:56 am

Selling a pristine Weston 686-10A for $1650 + shipping
and RCA WT-100A series 3 for $1200 + shipping

codyt · 2022-09-09 9:18 pm

I purchased an ACF rev.2 board from John, but the manual he included is for a different product. I’ve not had a lot of luck with emailing him, so wonder if someone has a schematic or manual PDF they could share with me?

codewritinfool · 2022-08-03 6:20 pm

For sale is one (1) Hammond 276X power transformer, NEW, with full-length leads.

$100.00 plus shipping. Located in St. Louis, Missouri, USA.

markrozen · 2022-09-09 8:29 pm

So I've just started this hobby several months ago and completed my first project which was the FW F6 and it sounds fantastic driving Klipsch Forte IV's so I am going to get rid of my Schiit Ragnarok 2 (PM if interested)... which brings me to the next project, a Pass pre-amp.

During the last few months I've stockpiled many components and have several Pass amp boards (F4, M2x) and pre-amps (Waynes LS, BA-1 & 3 gain stages). I am planning to be able to switch out the boards in the amp and build a pre-amp where I can switch out the gain stages.

Requirements for pre-amp:

Singe input (RCA's)
Support 64 step khozmo stepped attenuator (it takes a 5V/1A supply, I have a regular board from tubecad for this https://glass-ware.stores.yahoo.net/dulv.html)
Support any of the Pass gain stages with a +/-24V supply- I plan on using either a regulator board from tubecad or the super reg which I bought form the diyaudiostore
Two RCA outputs- one to go to the Pass amp and another pair that will go to a powered subwoofer (ideally after the volume attenuation)

My question is in regards to splitting the audio signal in this setup.

I have been trying to research a few different scenarios for accomplishing this:

A) tap the volume pot, isolate and buffer the split signal in some kind of simple opamp buffer. I tried searching for a pcb board that would make this possible and I found this buffer board https://phonoclone.com/diy-bb.html - it doesn't seem to be in production but I may have some luck contacting RJM directly. I imagine I would have to split the line from the volume pot to a board like this and also to the gain stage.

B) tap the output of the gain stage and add 100R and 220kR resistors to isolate the second output, like the Noir headphone amp

C) have one output RCA and use a y-splitter... I am skeptical of this solution, but I'm a dummy when it comes to all of this right now and I would not want to over-engineer a solution

Any comments on the project as well as how to go about the dual output is appreciated, thank you in advance!

audiostar · 2022-09-09 9:32 am

I don't have subscription to Voice Coil. Many of you know of Mike Klasco, his article on new thin film technologies for coatings and treatments by Oerlikon and Integran. Are these any good?

Thomasha · 2022-04-30 6:18 pm

Hi, just finished an amplifier with the OR120 preamp and a 12AU7 PP power stage:

The output stage uses a line transformer, with the 0, 2.5W and 0.625W taps and a 8 ohms speaker connected to the 4 ohm tap to get a primary impedance of 32k.
Plate voltage is at 240V, biased at roughly -12V, which should give roughly 0.9W in output power.

I added the 6dB feedback, as in the original amplifier.

The enclosure is a 1590N1 box with the tubes aligned.

PTP style build, since it is a prototype.

It uses a SMPS I got some time ago from ebay:
https://www.ebay.com/itm/133882043567
Much easier to install (and silent) than my own designs.
I think it proves the point, that one can use tubes and get 1W of power without a heavy transformer. The SMPS could be cheaper though...on the other hand, the parts are also quite expensive (mosfet, inductor and IC)

The final thing:

The FAC control is the switch at the back of the amp. It only has 3 settings: 4.7nF, 1nF, 470pF or, as I call it: too much bass, ok, lots of treble.

Cheers

wwwill · 2022-09-09 1:52 am

Hello everyone,
I am a very beginner in the world of audio, but this forum is a fantastic source of knowledge, so I first need to all diyAudio users for sharing that much info with the rest of the world.
So for my question, it is actually pretty simple.
I am looking for a solution to power the little (no Hifi) equipment I have at home that was given to me.
My goal is to use a pair of 6 ohms 40W speakers and a 1.5 ohm 20cm subwoofer to just get a better sound when watching TV, and listen to music via bluetooth from time to time.
My question is around the subwoofer.
Most 2.1 amp I found on Taobao (as I live in Taiwan) mention an allowed impedance of 4 to 8 ohms. (I have my eyes on this amp, but I am open to other recommendations)
What does that mean in my case ?
What happens if I plug my 1.5 ohm ?

It is probably a stupid question, but I can't find any clear explanation online.
Thank you every one

DaveFred · 2022-08-23 12:19 pm

Hello,

I seem to spend more time than I should looking around the net for different amplifier chassis and "good deals".

Recently I came across Hiendchina.com and their chassis prices/shipping look very good, but I am wondering if they are too good?

Link to Hiendchina Chassis Options

Has anyone bought from them?

They look to be the same people as Queensway from Aliexpress

Thank you,

David.

tufi979 · 2015-04-16 12:29 pm

Hello to you all. I have been browsing for a couple of days now about my problem but i was unable to find solution so i will try here 🙂
I bought used Denon avr 2802 faulty. Receiver turns on like it should relay cliks it responds on all commands ( volume change on lcd, switching between sources , mode selector... ) but there is no sound , i downloaded service manual , i checked all voltages on supply rails and everything looks normal and as it should. I traced input signal from dvd input and signal is lost on TC9459N , there is input signal present on pin 5 and 24 , but no signal is getting out from it od pin 3 and 26. so i assume that this chip is faulty??? But this is present only on DIRECT and STEREO mode on every other mode there is no signal present on input pin of TC9459N. Yesterday when i powered it up i have noticed that there is slight sound on speaker but very very faint and this only happens when you powered it up as soon as you change input source and return it to DVD again there is no signal. I have checked all big amp chips, there is no short on any of them . I ran out of ideas where to check so any help will be appreciated.
Thanks in advance.

AlexPPP · 2022-07-24 6:24 am

Hi all!

Please help me to identify the problem with my CD transport based on CDM9 Pro.
The bottom line is that recently my CD transport stopped reading discs, when I insert a disc, the motor spins up, no errors are written on the screen, while the swing arm slowly moves from the center to the edge of the disc and as soon as the laser head reaches the end of the edge , the disk starts to rotate in the opposite direction, while there are no errors on the screen.
The CDM9 block itself is working, since I move it to another of my same CD transport and it works without problems there, the same thing is proved by the fact that if I rearrange the entire CDM9 block from a normally functioning CD transport to this non-working transport, then the reaction is the same, i.e. the swing arm moves slowly from the center to the edge of the disc. It turns out that the problem is in the main board of the CD transport, but in which direction to look? Also, if you start the self-test with the STOP + << TRACK >> + POWER buttons, the focus test passes, the swing arm moves, the disk spins up, but when you exit the self-test with the PLAY button, ERROR 34 is briefly displayed on the screen. Unfortunately, I did not find a description of this error. Version of the microcontroller program on the screen when starting the self-test P133. The connecting cable between the CDM9 block and the main board was also changed to a known good one. The voltage after the voltage regulators is also normal.

Please help me identify the problem?

Thank you for your attention.

CosItsOneLouder · 2022-09-08 10:47 pm

I'm looking to Mod-Podge a pair of Faital.Pro 3" drivers (3FE22s in 4ohm). My intention is to use these as a wide-angle driver in a car, so I'm hoping this will improve their resilience to moisture and temperature changes. Due to their cost I intend to buy a couple of pairs, treat one pair then the other, measuring and listening as I go. The point I start making things worse I'll stop and install the other pair in the car!

Where do I start with watering down the glue and what consistency am I aiming for, how many coats and how heavy etc? Is something like the Visaton LTS 50 a safer bet for beginners? Just looking for a safe start point here so I don't trash the drivers straight away.

Thanks!

planet10 · 2022-09-08 7:12 pm

No politics please.

dave

geoturbo · 2021-07-14 2:12 pm

Fancing some updates, now surplus to requirement are some bits from iancanada 😎 :

- fifopi q3 with std clocks

- receiverpi
- accu 45/49 clocks

Not sure yet, but probably I would be having later to sell my Allo Usbridge Signature too, as rough prices please calculate audiophonics.fr single prices minus 25%. Goods are "already" located in EU (Italy). Pls for pictures/questions send me your e-mail via pm (kindly consider my ), I'll try to get back to you asap, shipping at purchaser's expenses/risks :wave:

Grazie,
Matt.

Bryguy · 2022-08-18 8:45 pm

I have a number of speakers for sale. Mostly my dad's, but since his stroke he's been unable to make use of so much audio equipment. Here is what I have:

10/10 Selah Tanzanite with built in Whomp 12 subs: $1800 OBO
8/10 Tyler Acoustics D3MX: $950 OBO
10/10 Verity Fidelio minty with boxes and manual: $1800 OBO (pending)
8/10 Magnepan 3.6 without stands: $1500 OBO
8/10 Klipschorn with Crites drivers and crossovers, and original drivers separately: $3000 OBO
8/10 Dahlquist DQ-10 needs refoamed and no stands: $450 OBO
8/10 Ohm C2, recapped, refoamed, refinished, ferrofluid replaced: $375 OBO
7/10 MasterSource 20M: $475 OBO
6/10 Mistral LS3/5A: $375 OBO
5/10 Acoustic Research AR-11 refoamed and recapped: $350 OBO
5/10 KLH Model 6 recapped: $150 OBO
6/10 Linn Isobarik Sara: $475 OBO

If for some reason you want everything, I would take $9500 FIRM

Pinox67 · 2021-11-19 2:10 pm

I am a SW engineer with the hobby of audio reproduction.
I have no in-depth experience with regards to electronics, but in the group I attend I have a couple of friends who build amplifiers (both solid-state and tube) for the local market (I live in Italy). Having measuring instruments, computer skills, and an acoustically treated room for music listening, I help them fine-tune their creations. I was also lucky enough to measure and listen to dozens of preamps from many brands, so, after some years of experience, I ventured into the difficult task of better correlating measurements to listening tests, also considering psychoacoustic effects in the equation (yes, very challenger!). This is based on the great work done by people like GedLee, Nelson Pass and Bob Katz.

The study I'm conducting with personal resources is in this thread.
In this following post I explain the rationales better.
Finally, the state of the study (still ongoing) is here and additional explanations here.

Some aspects are very technical, but I hope they can be understood by people with not too much knowledge of acoustics and electronics.
I would like to have comments/suggestions on the subject.

crayoneater · 2022-08-26 5:48 am

Hello, I am planning on making a 3 way crossover for a tweeter, mid woofer, and woofer. I have imported all the FRD and ZMA into xsim and designed a crossover. i am very new and was wondering if anyone could see if this looks good. Thanks!

Jeffrey 01 · 2022-08-06 4:27 pm

Good morning everyone. So am looking for a Frequency generator to send through my speaker drivers and test them. I see a lot of knock offs on e bay and amazon? I can buy a used one but, am looking for one I can plug my speaker driver into and it does sweeps as well? Am looking more of a teaching and learning instead a click of a button by using my Woofer tester #2. I did see one on line from a science website about sound kit and Demonstration about sound and sand and patterns. How to It do with the earthquakes and other things. It only went up to 1Khz and I need it to go at least to 20khz or higher. Like the picture I posted? Thanks Jeff

harrylime6 · 2022-09-09 1:30 am

Offering $60 for a pair of unused M. Rothacher MOFO boards
Items found.
Offer withdrawn/cancelled
Thanks for looking
-Edward

SirPaulGerman · 2022-05-29 1:01 am

I was able to get a nice B&K ST-202, I think is time for a restoration, I noticed the mods by musical-design and they are expensive.
Can you guys reverse engineering those upgrades by musical-design ?
I think the same upgrades are applicable to the Hafler series of amps

https://www.musicaldesign.com/MC_BK_Amp_Mods.html

https://www.musicaldesign.com/Demo_Used.html

Or if you guys have a list for updates to the ST-202 that will work to

Earplay2020 · 2022-06-12 2:53 am

This query relates to a recent build of a SLOB, which uses 4x8" drivers per side, configured push-push. The speaker was my variation on XRKs XSD (a much more budget version!). I figured I'd post a separate query to avoid cluttering up his build thread.

My question is about the merits of series vs parallel wiring for woofers that are configured as push push. I currently have them in series, as I originally had a passive xo and it helped with impedance. I now have a fully digital crossover using dsp.

When playing some bass heavy tracks I noticed that a woofer on one side appeared to be showing a much greater level of excursion than its opposing driver. Bearing in mind the drivers are cheap as chips - could this effect somehow be a result of series wiring? The obvious answer would be to wire them in parallel and compare, but I'm wanting to understand if there is any theoretical reason for what I observed?

hifisuran · 2022-09-08 10:37 am

Hi experts I have an Akai 1710 which I would like to use the amp section and external speakers. I’ve seen many YouTube videos showing this done and with 4wpc and my speakers at 96dB I should get some sweet sound. The tape deck itself doesn’t work that great anymore and no one around me is qualified or experienced in fixing.

Anyway I hooked up my streamer via coaxial to a DAC amp and then took the line out of the DAC and plugged into the line in of the Akai

There is absolutely not sound at all. When I switch the amp to record more then I can see the needles move which tells me the line in circuit is dependent on record mode being on ? But why no sound?

I then took the cables from line in and plugged them in to line out and lo and behold I had sound from the external speakers 1/4 inch jack albeit really low I’m taking maybe 20db.

Before I dismantle it and separate out the tape from the amp.

What do I need to do to activate the amp section when I plug in an input source like a streamer or CD player.

I am also aware that there is a black 4 pin connector plug that links the amp to the tape but not sure how to modify so that the amp itself can be powered.

But yeah if you have any advice on how I can get the amp to output sound that would be great.

Ps I had a valve amp it broke Cost of repair too much can’t afford new one yet so thought why not try this

Ps playback volume during tape play is loud and clear just that it has a tendency to get stuck sometimes and I have another deck now anyway technics rs1500

777funk · 2022-08-24 9:01 pm

I have one of these boards (a clone of the TI example) running from a guitar preamp and it sounds great to my ears. BUT... it hums when I have the guitar volume turned up (magnetic pickups). No hum with guitar volume at ZERO. I was initially thinking it was my cables, but I noticed that when I unplug the supply (24VDC switch mode brick) the hum goes away for a second and the signal comes through just fine until the filter caps discharge.

So I'm thinking PSU issue.

But... is there something I could be overlooking? Do I need to just add more filtering?

Bigman80 · 2022-09-08 7:41 pm

Hi all,

I was sent a BB3 that was exhibiting some noise on the MM setting, so we took it back and tested it for about 12 hours without issue.

However, back in the guys system it appeared his issue reappeared.

I've had it back and replaced it with a brand new one. It has not exhibited any issues here.

So, I'm not going to use it for anything and rather than dismantle it, I thought I'd offer it here on the understanding that MM may play up.

MC is absolutely faultless, so there we have it.

£125 will cover the PCB and delivery in the UK.

html multiple images

vrbbra · 2022-09-07 9:20 am

Any experience with help tweeter (5-10 kHz only with one capacitor) + Markaudio 12PW. Ceramic, aluminum or soft dome
https://sbacoustics.com/product/sb29rdac-c000-4/ ring radiator
https://www.morelhifi.com/product/cat-378/
https://sbacoustics.com/product/sb26adc-c000-4/ alu
https://sbacoustics.com/product/sb26cdc-c000-4/ ceramic

ANDYLASER · 2021-11-26 8:25 pm

2x60W/1x120W audio amplifier PCB & LM4780 Amplifier Chips

I have 2 sets of boards and chip amps that were purchased in this GB, but never got round to building. I am therefore offering them for sale.
I also have an additinal 2 chipamps without the boards that are available.

I would like £35 per board/chipamp combo. EDIT: £30 ~~SOLD~~
I would like £25 per chipamp on its own. EDIT: £25 ~~SOLD~~
Signed for and insured postage is £5 UK, £10 International.

EDIT: Both PCBs have been sold. The chip amps are still available.
Thanks.

ajvar · 2022-09-09 7:17 am

Hi,
Anyone got the original bare Parallel-86 boards from tomchr that are available for sale?
Need quad of them as I intend to make the Parallel 486
Thanks,
George

mrjayviper · 2022-09-08 5:28 pm

a picture paints a thousand words so... Thanks in advance. 🙂

Efaure · 2022-09-09 5:57 am

Bonjour

J'ai un Ampeg B15 2012 réédité, un modèle en série limitée, inspiré des Ampeg B15 historiques pour lesquels vous avez fabriqué les transfos (voir photos jointes)

Le transformateur (voir photos) a grillé et je recherche soit :

- pour le remplacer (avez-vous un modèle ?)

- soit pour le reconstruire ou le refabriquer ?

alimentation 220/230V

Pouvez-vous m'aider ?

Merci

OlegSh · 2016-12-24 2:24 pm

I've just got Focusrite Scarlett 2i2 (2nd gen) USB audio interface. The intended use is measurements of audio circuits. So far I've done basic loopback tests (posted here). Since it is the first time I measure audio signals I need some guidance where to start to make my results meaningful.

The first question is what kind of probes do I need? I have a couple of 1/4" TRS terminated cables to start with. Since the inputs/outputs of the 2i2 are balanced it probably makes sense to use balanced probes instead of single ended. Is there a recommended probe construction to start with? So far I plan to measure line level circuits and headphone amps. I may also measure power amps and speakers later which means I will need switchable probes with different ratios (1:1, 1:10 etc.). Also should I worry about proper probe's impedance termination?

Hope to have some pointers!

Merry Christmas!
Oleg

adambennette · 2022-09-06 1:23 pm

I have made a number of amps, PP and SE operating in Class A1. Now I am interested to push to Class A2. The reason would be to either get more power, or be able to operate at a slightly lower B+ (or a bit of both).
My target for now a type 50 or a 2A3. I have not found plots of grid current for either anywhere, nor for type 45. Is this because they are unsuitable for Class A2 or simply a common omission?
I know that A2 means you need a driver that can deliver current and also that the fixed bias source must be shunt regulated so that the bias voltage is not affected due to the rectifying effect of the grid current (G1 becomes a second 'anode'). What I don't know is, even approximately, how much current is required. For a 211 or 845 it can be a lot, maybe 100's of milliamps in the extreme.
My driver is a 45 or a VT25 (10Y) in SE into a 5k:5k interstage with a 30mA DC standing current rating. For bias I propose this:

I believe that most bias circuits such as by Pete Millet, Rod Coleman or Guido Tent can only sink a few milliamps. Is that right? If the driver has to deliver the meat and potatoes of grid current, what is the effect at the bias source of the rectified grid current?

BTW: I would like to use fixed bias so as to limit power loss and heat generation in a cathode resistor, however, with cathode bias this 'rectified G1 current' problem should go away since the grid would have a direct route to the low impedance 0V line through the interstage secondary winding. Yes, the interstage tolerates standing DC, although the rectified G1 current would in reality be a pulsating DC signal.

Also: The type 50 recommends no more than 10k ohms in the grid circuit, a low value.

Any comments gratefully received.

Randy Bassinga · 2022-09-07 3:08 am

Hi all
I lie, it's about another tube PSU 🙂

I am interested in making a PSU like this below. I am reaching out to see if anyone has experience of any schematics that are known to work well, or any past projects about this. I would prefer to come up with a thru hole type only design and no smd

Commercially made example - click this line to see

I am also very interested in any collaboration regarding design and PCB. If there is a usable PCB design, I will order 20 or so and only have use for a few, so will make the rest available for cost plus postage to anyone who contributes to this. Also, I will be ordering parts for this from the better brands in small bulk lots, so will include things like vishay resistors and wima or nichion or whatever is considered upper shelf parts. Again, will make my extras available at cost plus postage to anyone who collaborates on this.

355F1 · 2020-10-01 9:42 pm

Audio Research SP3

Hi,

I would like to replace the volume control and source switch of my SP3A-1 preamplifier. I am not an expert, just an old newbie. Any help, suggestions and recommendations will be greatly appreciated.

This is the list I was able to put together according to the suggestions I found on DIYaudio.

Goldpoint V47 [$246], TKD 2CP-2511 motorized [$114] this model is used in Kondo, Lamm and Audio Note, the Elma 2 pole 47 way switch [$231]. Switchable attenuators: ELMA 04-2264 [$101] and Seiden 32012 [$80].

There is a new ALPS HQPro but the price is out of the question, too expensive for me.

I do not know if I should get a 2 pole 6 way or a 4 pole 6 way switch. What's the degree of difficulty?

On another note, how about bypassing caps with Mundorfs or Jupiters, etc?

Thanks much in advance.

LectroMoto · 2022-08-17 5:55 am

Tested on my trusty low mileage TV-2 tester where a reading of 100 is considered NOS testing.
Strong Pair Ken Rad 6SN7GT alligned ladder black plates. Test 92,85/59 and 92,89/59. $75/pr
Batch Match Pair RCA 6SN7GT Grey Glass. Both have batch codes of 8-52. Strong balanced results at 95,96/59 and 94,93/59. $50/pr
Tung Sol USN CTL 6SN7WGTA with brown micanol base TV7 test 75,84/59 $20.
Sylvania tall 2 hole plate 6SN7GT TV7 test at 94,120/59 $20.
Sylvania JAN CHS 6SN7WGTA Chrome top 90,98 /59 $20.
+ shipping or make offer on all.

beeah · 2022-09-08 11:58 pm

I am selling a pair of Lundahl LL1620AM amorphous core, single-ended output transformers. They are gapped for 40mA and were used with 45 tubes exclusively. They were purchased from K&K Audio in November 2018 and took quite a while to arrive as they are built on demand in Sweden.

Included are the Lundahl covers as well as the K&K Audio boards that greatly simplify the configuration of primary and secondary. They are presently configured as 6K primary, which allows for 4, 8 and 16 ohm secondaries.

They sound fantastic, but I have recently taken a detour down the solid state path after 20 years of tube DIY and would like to fund other projects. Mostly, though, while I still fire up the amp from time to time, it's a shame to let such beautiful iron sit idle.

Asking $775 including US shipping. Payment via PP F&F, please; please see my 100% feedback on USAM (user name 'joesever'), eBay ('faitu'), and under username 'beeah' on still others.

davodavo · 2022-09-08 11:39 pm

Hi. I've got a Bogen DB240 receiver (transistor, around 1970) that's a real oddball....trying to bring it back to life. Don't ask why ;-)

If you have one, working or not...please reach out to me.

Thanks

pipestone · 2022-09-06 6:06 pm

Drivers are:
*8" Scan-Speak classic woofer 21W-8552. Foam is shot. may replace with interesting substitute as I like the beryllium copper look. Any suggestions of similar specs appreciated
* Specs attached in PDF

*4" Eton 4-203/25 HEX. Foam Shot. Same as above
* Specs

CONE TYPE: Hexacone
SIZE: 4in
SPL(2.83v): 89db
WATTS: 50
Z: 8ohms
FS: 63hz
RANGE: 63-4Khz
VAS: 5.3ltr
Qts: .24
Xmax: +/-1.1mm

I haven't pulled the tweeter yet. but something that would correspond to above idea of copper may be attractive.

cobretti · 2019-05-24 9:31 pm

Can someone post a schematic how the FX loop should be connected in Marshall amp? I would like to add FX loop to my EL34 50W. Thanks.

zintolo · 2020-08-02 9:50 am

Hi,

I've seen many DC/DC converters to get 6.3Vdc for heaters from 6.3Vac, but why have an e tra winding on the power transformer if it can be directly done through SMPS from the main supply? Less weight, less money, less heat.

But... I haven't found any available on the market.
Does someone know if there's someone producing them? Or if a 5V SMPS can be modified in the voltage divider to get the results?

Due to the initial overcurrent due to low temperature of the heaters, I would consider a safety factor of 4 for the needed current, in order to be on the safe side.

Thank you in advance for your answers.

Kind Regards
Roberto

Sjef · 2012-02-17 9:20 pm

Not really DIY but today I was at a demo of the new Kef Blade "50th aniversary" loudspeakers.
Boy what a bad loudspeakers these are. They sound like plastic, are very resonating in the lower mids. Bad definition in the low end. Mids and highs very polite plastic hifi sound. Shut in sound. In others words quite the opposite of what I'm used to at home. Oh man never been so happy to here my own DIY system again. Listening to them from outside the room was plain terrible. In fact that was what drew my attention in the first place. When I went over to see where this terrible sound came from they invited me in at the demo

Just googled the Kef's and found out they are asking 30.000 dollars for these. I guessed they would sell for 5000 dollars or so and even then they really needed some rewrk specially on the housing and the woofers. I allready read some forums where people try to copy some of the design without hearing it, please keep up your own ideas and design. The 'professionals' don,t do it any better in this case. I was pretty shocked to be honoust. (And very happy that I have followed my own ears and ideas in loudspeaker design)

schomosport · 2022-08-06 6:00 pm

Bought an Audiolab 8000A bout 20 years ago. The MM phono stage has never worked (tested with two known good turntables). I have never owned a MC turntable so I have no idea if that stage is functioning. I would now like to get at least the MM stage working so that I can route my turntable through the Audiolab instead of through a second Arcam amplifier that sits alongside. I have the 8000A service manual, a DVM and can read a circuit diagram and identify components. Beyond that my electronic equipment fault finding skills are very limited. Suggestions where to start fault finding would be appreciated. There is also some low volumes hiss on the left channel when using other inputs such as CD player and SlimDevices, not loud enough to be discernible at listening volumes but noticeable between tracks.

audiostar · 2022-09-06 2:36 am

https://patents.google.com/patent/US3246085A/en

00940 · 2022-09-08 8:02 pm

It's been a while but I've got some time on hand so I'm putting together a bunch of stuff I acquired over the years: some 12" vintage fullrange, a pair of Peerless XT25BG60 in WG300 waveguide and a zoudio dsp/amp. All that housed in 100 litres BR boxes (100*40*30 cm).

I'm not expecting wonders but it's a fun challenge. Big speakers are a pain in so many ways though.

A first picture, the front is valchromat mdf, I'm waiting on some walnut veneer for the plywood sides. I messed up the holes for the 12" so I had to improvise something to cover my inaccuracy.

birdyman · 2010-02-10 4:13 am

I am working on a Crown Power Tech 2.1 amp. One of NPN transistor is labeled "2961". Any one know specs of it or full name of it?
On Crown Power Tech 3.1 schematic it is used opposit side of 2n4125 as if "2961 " as a complimentary pair to 2n4125. But 2n4123 is complementary to 2n4125 and Crown power tech 3.1 uses 2n4123 on opposit side of 2n4125 then it uses "2961" npn's. 😕 Can anybody clear this up??
Thanks in advance.

Bryguy · 2022-09-06 9:28 pm

Howdy folks. I have a question for you all. I have been looking around at some of the various DIY power amp designs available to us, and I have really been thinking about maybe trying to build one for myself. It is not that I am unhappy with my current amplification, I really just would like some toys to play with, and I welcome any sonic improvements to my system that may come along with my tinkering 🙂

This being said, it has occurred to me that if improved sound is my ultimate goal, I might be better served (and I'm sure I'd have just as much fun) with taking a closer look at my current gear and seeing what I can do to improve it.

What I have right now is a pair of Classe DR-8 monoblocks from the 90's. My experience with modern amplification is pretty sparse, but compared to a lot of the sub $1,000 readymade commercial power amps I've heard, I have far preferred my Classe's. (I have heard some Emotiva power amps and a few other pieces which I have not cared for much at all)

So, my question, and since I don't reckon many of you have heard these amps I'm guessing it will be hard to answer... Should I move forward and start fresh with some well known modern designs? (I have been looking at ZM's Babelfish XA252 and the Alpha Nirvana SE power amp) or should I pull my aging Classe's apart and start tinkering around with replacing some parts with newer and better ones?

https://www.hifiengine.com/manual_library/classe-audio/dr-8.shtml

I am new to diy audio, so whatever I do will be very daunting to me. I am enthusiastic about facing whatever work lies ahead though!

JRKO · 2022-08-19 10:04 am

Please check this post for complete list of all parts still available

10x C2547 no idea why I purchased these - £5 the lot
6x Geree DC-DC Boost converter 10A 250W (https://www.diyaudio.com/community/threads/aksas-lender-preamp-with-40vpp-output.314563/post-5260733 post 316) - £8 each
2x Selectronic r-type transformers. 30v with dual 24v secondaries - £20 each
1x pair DLH amp boards (https://www.diyaudio.com/community/threads/dlh-amplifier-the-trilogy-with-plh-and-jlh-amps.311567/) - £10 the pair
1x pair of F3/F3J boards - £15
1x pair of LU!014D matched by mbrewennwa - £18 per pair
2x volume/selector knob bakelite long design including grub screws - £8 each
1x complete F3 Amp boards, power boards and transformer (see image for transformer details) - £100

Parts Just Added post 8:

1x Salas B1 Mezmerize board. Dusty as its been an age since I used it so sold as seen - £50
1x Academy Audio VCU board Rev 01 & remote - £45
2x ConnexElectronic SMPS300REh 230v version with 24V output (18v secondary output) for use with FirstWatt Amps - £60 each

Sensible offers on multiple items considered

I'm happy to help out (within reason) on postage on the heavy items

For Sale NEW TKD 2CP2500 MOTORIZED

For Sale Preamplifier Chassis - NEW

Attachments

Attachments

WTB 1W tantalum resistors

WTB Russian/Soviet noval tube base/socket

Attachments

Attachments

WTB 50 D3a NOS Pentodes

Attachments

Attachments

Attachments

LAVOCE WAF153.00 15" WOOFER​

woofer specs ar here http://www.loudspeakerdatabase.com/LaVoce/WAF153.00​

do you think that i can make a usable result out of them ?​

WTB Hammond 370BX power trans

For Sale Laboratory Tube Testers

Attachments

For Sale FS: NEW Hammond 276X power transformer

Attachments

Locked Elizabeth has died

For Sale Many speakers

Attachments

Attachments

WTB Pair of MOFO boards

LAVOCE WAF153.00 15" WOOFER

woofer specs ar here http://www.loudspeakerdatabase.com/LaVoce/WAF153.00

do you think that i can make a usable result out of them ?

Locked

Elizabeth has died