I have just turned on my central heating, and each year it becomes more and more difficult.

It is a relatively old (1996) natural gas boiler, but it is from a good maker, good quality, and it is efficient, safe and reliable.
However, restarting it at the end of autumn becomes more and more difficult, and I have decided to investigate.

The problem is that the gas pilot doesn't hold: as soon as I release the starting knob, the flame goes away, even if I keep pushing it for tens of seconds.
This boiler has an originality: the safety loop is completely autonomous and independent from the rest; it has no external supply.
The safety thermocouple is not directly connected to the gas inlet control, but it is daisy-chained with various safety switches before: overtemperature, overpressure, etc.
The voltage delivered by the thermocouple is tiny: in the 10 to 20mV range, thus any drop along the safety loop would cause problems.

I first thought that the switches were the culprits, but they only drop 1 or 2mV. I then checked the wiring, and discovered significant drops: up to 6~7mV.
The cables themselves cannot be the cause: they are good 1mm² copper, and they have always been in a clean and dry environment.
The connectors are Faston type, regular 6.35mm and the smaller size. When I measure the drop between the male spade and the metal of the female receptacle, I only see a negligible, sub-mV drop, thus the only remaining possibility is the contact between the cable and the receptacle. They are professionally crimped, and look in good condition, yet there is a drop of several mV. I have always been taught that properly crimped connections are airtight and very reliable, but it seems that exceptions exist.
The same kind of issue could affect speaker connections for example, and cause tiny sound degradations: I didn't verify it, but I imagine that this contact resistance is non-linear too, and could add some distortion

Brand new unused pair of F-2013 opt. In factory boxes with tags yet to be fixed to transformers.

Transformers are in Australia from where they will be shipped.

Price for the pair is AUD$1800 (approx USD$1215) and excludes shipping.

Since I have completed miro1360 AD1862, AD1865 DACs and they are working perfectly now I am left with few extra boards which I don’t need any more, and I am putting them up for sales.

• AD1865 Bare PCB x 3, 5$ a piece, please understand that while JLCPCB makes 5 pcbs of 100mmx100mm for $2, but there is hefty shipping and customs included, that is why the PCB cost is roughly 5$ a piece, same for other PCBs.
• AD1865 Complete PCBs with shift registers and all components excluding AD1865 and the operational amplifiers, 40$ per PCB. All thru hole components are mounted on top layer for 1 PCB, exception are supply, audio connectors and the ICs and for rest of the PCB the components are mounted on bottom layer so that one could play around with IV stage.
• AD1865 complete DAC with AD1865-NK and OPA627, just 1 DAC for $120.
• AD1862 Complete PCBs with shift registers and all components excluding AD1862 and the operational amplifiers, 40$ per PCB. All thru hole components are mounted on top layer for 1 PCB exception are supply, audio connectors and the ICs and for rest of the PCB the components are mounted on bottom layer so that one could play around with IV stage.
• Power Supply PS1 partially completed 1 PCB for $45, LT3015, etc mounted, diodes mounted.
• Power Supply PS2, partially completed or bare PCB diodes mounted, $15 per PCB, I only have 2 extra.
• Signal switching PCBs 3 PCB in total, semi finished means with the exception of logic ICs all components, connectors have been soldered. $25 per PCB.

Shipment worldwide is flat $15 for upto 1KG.

Payment is to be made to my skrill account, sorry paypal doesn’t offer service in my country.

Shipping will be through snail mail and tracking number will be shared via PM.

Hi, I'm a longtime lurker, first time poster. I've searched the forums on this subject but haven't found what I need.

My old NAD 2600 has been having the typical problem of spotty sound on one or both channels at low volume. When the volume is turned up, the sound punches through. I've reflowed the solder joints throughout, and opened and cleaned the relays with DeoxIt and a brush. That cured the problem for about 5 months, but it's back now. Reapplied DeoxIt and a repeat cleaning isn't working anymore.

I can temporarily fix the problem by turning the amp off and turning it back on, so that the relays click off and back on. A day or two later, it will start having problems again.

I want to replace the relays, but don't know where to begin to source a part. The original part is listed as PXS-2405U, which is now unavailable. There doesn't seem to be a datasheet available for the part, and there are no markings on the relay itself to indicate its specs.

The service manual I'm working from is available here:
http://user.faktiskt.se/phon/misc/2600.pdf

I've attached an image of the relevant part of the circuit.

Can anyone help me find a substitute relay? Preferably a good sealed one, that won't be susceptible to these kinds of problems? I understand how relays work, but am not familiar with their parameters and how to choose some for this application.

I know there are repair places that work on these amps specifically and replace the relays, and I'm wondering what they're using. I'm not really willing to pay $150 to find out.

Thanks!

I was hoping to get a little insight into making a speaker cabinet for a project I’m considering. My thoughts are, when looking at a ‘high end Radio Shack or Bose’ speaker or a Wilson Audio/Focal/Magico speaker, when it comes down to it all you really have is a driver mounted in one side of a 6 sided rectangular solid box. One ends up with a stack of boxes with drivers on one side of their respective boxes. With all due respect to those willing to share ideas and opinions, it’s a given that a lot more than what I said has gone on to get that driver mounted in the box. I’m not interested in construction details of the box or anything regarding crossovers. I’m curious about what one does to optimize the box to the particular driver.

I am considering a MTMWW array, all sealed enclosures, using Scan-Speak drivers. D3004 tweeter, 12MU upper mids, 18WU lower mids, and a powered sub, probably a Rythmik servo sub, tbd. A Marchand 4 channel active tube crossover will be used feeding a stack of amps, again, tbd. We don’t need to talk about driver selection or crossovers or amplifiers. The upper mids and lower mids will either be in separate enclosures or each driver type/size will have both drivers in one box. THE QUESTION: with a driver(s) in a box, with minimal baffle area around the driver, attempting to not have parallel sides of the box, with a mic 1 meter directly in front of the driver, what does one test for when optimizing box volume? On their data sheets, Scan-Speak recommends a box volume for sealed enclosures. Madisound also recommends a box volume for sealed enclosures. I’ve built the Klang&Ton NADA kit which uses the 18WU driver and am happy with how it sounds. Its volume does not come close to either Scan-Speak or Madisound’s recommendations. These numbers are far enough apart to not quite know what’s ‘right’. Does one build box volume so the driver and box plays as loud as possible? Does one build the box volume to increase frequency response? When building a speaker cabinet, not considering materials or bracing or resonance, I think you have only two variables to consider – shape and volume of the cabinet. In this case, the shape is more or less given. The box will be a rectangular or trapezoidal solid shape. I think I’m left with volume to evaluate. Each driver will have its own discrete amp channel driving it, and each amp will have a restricted frequency range to limit sending too low of a frequency to a driver that might be damaged by too low/too much power/bottoming out concerns. I’d like to know what to test for when optimizing a driver to box volume.

I look forward to any help you guys can offer. Thank you.

Hey all!
Looking to part with my KSL-M77 clone kit with all nine tubes included! All the 12AY7 tube sockets have tube savers + silicon rings as well

Ended up being a project I didn't have the time or energy to finish 🙁

Only things that need to be purchased still are the chassis + power transformer.

Willing to part with just the tubes as well if anyone is after those.

Let me know if you're interested! Hoping to get $375 + shipping for everything (shipped from Calgary, Alberta, Canada)

Willing to part with just the tubes for $250 + shipping

Orchard Audio equipment will be in 3 rooms at CAF2023 -- Nov 11th to 13th, 2023

Room 708 -- Hollis Audio Labs
You can read more about what Rich is doing here: https://www.audionervosa.com/index.php?topic=8962.0

Rooms 857 & 859 -- Endow Audio (www.endowaudio.com)
One room will have Bravura 7.2 speakers with a Starkrimson Duo (150Wpc Gan stereo amp)
The other room will have Bravura 12.2 speakers with a Starkrimson Stereo Ultra 2.0 (500Wpc GaN stereo Amp)

I will also be present at the show on Saturday and Sunday and will most likely be in any of the 3 rooms listed above at any given time.

For those of you that use FB, please RSVP on the event page.
https://www.facebook.com/events/1202368380943195/

Regards;
Leo

Hello All,

Finally getting to wiring up my Pascal Modules - purchased two Pascal T-PRO2 II modules from fellow DIYAudio member here a whle back... and just purchased two Eval modules for buffered input (XLR CH1 CH2)

But only now realized its the Eval Unit for the S-PRO2... are they interchangable? I know these S-PRO2 Eval modules have switches for BTL, but the T-PRO2 modules are 150W / 500W, and cannot / should not be bridged.... Also two jumpers - one for TEMP/VAC and one for 4 Ohm BTL...

Any help out there?

And Datasheet refers to T-PRO2 II Application Manual...where is the Application Manual for these T-PRO2 II units? Cannot find anywhere...

LM , TDA chip amps very weak bass, but best mids and highs, very weakly produce low frequency.

lot of experiment doing improve bass, but not good result

finally understand usa europe people not like low frequency sound 🤣

Hi,
I am trying to help a friend to fix the Luxman L-560 unit he owns, for that we need Schematics.
Any chance someone here can put his/her hand on it?

Cheers,
Shay

For sale is a pair of ScanSpeak 18W/8545K00 woofers. These have been lightly used and are in great condition. No cracks or splits on the cones or surrounds.

Asking $220. I will cover shipping within the US and PayPal fees at my asking price.

Please let me know if there are any questions.

Thanks for looking.

DaveJ

For this automatic direct drive record player model (sometimes only mentioned "RP-2626" or "RP2626") I don't find both a repair-kit and some repair instructions on the web. Main issue is the fact, that the tonarm don't go to the record after press the "START" knob. Basically the same reason than on several DUAL models - go to the first image under
https://www.dual-board.de/index.php?thread/83881-was-ist-ein-pimpel/
Go also to post #27 under
https://www.diyaudio.com/community/threads/dual-721-question.313998/page-2
and
https://www.diyaudio.com/community/threads/dual-turntable-steuerpimpel-sub.239593/
Maybe one of the member know, which parts are to be replace - thank you very much.

Hi all,

I know this is the loudspeaker forum but this is directly related to my B&W 802s3 speakers.

I bought a Bass Alignment Filter from a fellow DIYaudio member. He is a very nice guy and I am happy with the parts he sent, the price for them and the promptness of the transaction.

However none of it came with documentation of any sort. I am piecing it together as best I can.

The reason for the post is...

1. Anyone recognize this PCB and have a link to ANY documentation?

2. The signal lead pads (in and out) on the PCB are not marked for positive or negative. Ground is center. The outside pads are one circular and one square. Any guesses as to which is positive?

3. The transformer is labeled as dual primary and dual secondary. With secondary as 0-15vac / 0-15vac. However I am getting 22.5vac off both secondaries. Rechecked the jumpers on the primaries to make sure I didn't series the primaries but it doesn't appear so. The rectified DC side is 29.5vdc. Added an LED for some type of load on the DC side but the output of the secondaries didn't change. Kit type PCB's, anything else I can check?

Any help would be appreciated.

My amps are balanced in so the factory BAF I have from B&W doesn't work in this scenario.

Hi!

I'm trying to get rid of oscillations in the MC part of the phono stage of the Cyrus Two Issue 07 amp, but to no avail. The amp belongs to a friend, he complained about no sound on left channel over phono (MM). It was "overhauled" years ago, but only C43/C44 were changed back then. I found almost all caps were dry and the RIAA opamp (A5) was oscillating.

I changed all electrolytic caps except main filter caps and renewed the regulators. After that, the amp seems to work fine, but now I have oscillations on both MC opamps. I added 100n to the C67/C68 and C72/C71, I tried even to add some capacitance directly to the opamp leads - no change. C3/C4 were not populated on the board, but they are not marked as "deleted" in the part list. Added them, but still no change. Any other steps I could do, before I disable MC section completely?

Thank you!

I want to know crossover frequency what should be it ?


This is my subwoofer specs Bass Enhancer, Flat Cap. 5,25 Inch Low frequency (40Hz to 160Hz) driver with Amplifier sub out/Low pass filter connection. Full Range Driver with 15W direct Car Head output. 6.5cm depth required to use in car door pad. Best for home theatre stock driver


Tweeter/satelite speaker is 4 ohms 2.5inch

I'm almost done my first build, and getting ready to enter the testing phase. I've never built a set of speakers before, so it's been a learning process, that's for sure. Lots of little things I'll do better next time, and lots of small defects that likely only I'll ever see, but so far I'm happy with how they turned out. I don't have a real workshop, so I had to relay on our equivalent of Home Depot to do the cutting, the routing in my buddy's backward, and I finished with most of the assembly and painting in my hallway. But I purposefully wanted a white faced speaker with wood back and sides to match my flooring and my entertainment unit.

Main driver is the Dayton Reference RS180-8 and the tweeter is the SDC26ADC-C0001. The veneer was a white oak. I still have to clean the front face up a bit more and I'll likely put on a light coat of furniture wax. But I couldn't wait to set it up and take a look at least.

Thanks for all the inspiration and help here so far!

Tested on a Hickok TV7 where 38 is low.
71 and 75 test And thoriated tungsten fillaments
120$ and shipping
thanks rick

Hi, I'm trying to take a 1.5v audio signal and split it to 2 outputs, one with the phase inverted at 1.5v and one non inverted at 1.5v



I currently know two ways of doing this, the first is using a opamp chip with two comparators to make the circuit below. I have tested this and it works OK.

Vin is where audio signal comes in. A dual opamp is used as it has the two comparators needed to make this circuit. I used 10k on each resistor and it worked ok, a little background noise
Note that load is taking one inverted input and one non inverted input (from output of each comparator)

The other way which I have not tested is by using a single transistor and a resistor network to split phase, would this work as well as an op amp?

with pcm1704 there is invert pin, now need to invert for older dac chips and not sure how to do this properly.

I have a Neutrik 12-pin DC cable but it's too short, so I will need to make one (or pay someone to make one). 12 pins of 22awg, times two.
I am not terrible at soldering but it's sort of a twice a year thing for me, and these pins are little. I couldn't hold a candle to someone like my father, who was godlike at my age.
My questions are threefold:
1. Can someone who is barely skilled do this or is it simply a bad idea?
2. What's the best way to strip 22awg wire?
3. Any other tips or tricks?
(details here: https://www.neutrik.com/en/product/mscm12)

Hi

I have two pairs of Seas FU10RB 8 ohm version (unused) for sale.

$75/pair + shipping, or $140 + shipping for both pairs.

Items are located in California, and can be picked up in either Sacramento or SF

S

Hi,

I just bought two line filters. Each enclusure holds 2 TDK filters, a ZAC2220-00U and a ZAG2220-11P, cross wired.
I guess this is for better filtering.

Which filter should be on the side of the wall plug?

Regards, Gerrit

if anyone has this board let me know the diode code, mosfet code, and if there is any equivalent resistor to replace the 2k4 ohm 1/4watt 5% resistor.

Hi, I have a Yamaha cassette k960 and the problem it has is that between songs or without playing a tape with play on it has a lot of background noise.
I have checked all the components and I don't see anything abnormal .You might think they are the Fet K 150A .
thanks in advance if anyone can help me.

The transformer is undersized (I've seen recommendation of 1.5x expected output power) but what does "undersize" actually mean?

Is it undersized on high volume only or undersized for any volume level? (I believed if the amp is class A then I would expect to have problems)

Thank you.

eDIT1: or when there's a low frequency tune (lots of bass), it'll be undersized even at low volume?

EDit2: 2x 4A 25VAC (for a transformer rated 100VA) for the secondaries and using unregulated supply. (just a rectifier bridge + some capacitors)

https://www.diyaudio.com/community/threads/drive-current-distortion-measurement.402566/

Greetings all,

It's been while since I been on DIYA...
I've run a couple of Pioneer repair threads over on AK.

I just purchased an 80's Pioneer pre-Elite A-77X (S/G multi voltage model) as a backup to the one I purchased in Europe when I was in the Army in Berlin.

The first thing I noticed was that the voltage line selector switch on the back of the unit was broken

The part number is AKX-507. That part seems to be "unobtainium" here in the States. This place in England apparently has the part but is unwilling to ship to the U.S.
https://fixpart.co.uk/en/product/pioneer-akx-507-selector-switch

Can anybody lend a hand?

Thanks for looking.
S~

Hello,
Can some simulation software expert simulate this electrical diagram that I found among my notes in the drawer?

Just finished one BPA300 mono block and used RMAA to do some measurement.



RMAA result :



More photos and details can be found at my site :

http://www.shine7.com/audio/bpa300.htm

Hello,



I have a broken Mark Levinson 333 that I want to repair for myself. It's working so far, but I have a problem on the Volage Gain board, which is why I can't figure it out at the moment.



The following were defective so far:



Q37,Q39 and the CR55 had passage.



After I replaced the parts, the Q36 gets around 100°C, but in the other functioning channel it only gets around 40°C



I had measured all the transistors so far and didn't find anything unusual. What could that be?

trying to figure out where is the correct way to go about wiring in a power indicator lamp on my project Bell Air amp.

Has anyone tested what's the difference between e.g. a BMS 4540, Eminence n151m and B&C DE360?
Or how about other small CDs that can play up to 20kHz like the Celestion CDX1-1425 and CDX1-1412?
Which can play the lowest, highest and has the least distortion etc?
My goal is to play at least close to 20kHz flat at up to 125dB/1m, so not that much for a CD and it will go in a constant directivity waveguide.
I have 40-90W per channel and fully parametric DSP to correct the output.

Here are some tests I've found, but they don't use the same waveguides so I don't know how comparable the results are:

n151M test

DE360 test

CDX1-1412 test

Does anybody know who makes those push-down poke-in ribbon cable connectors used in Onkyo hifi equipment? I can't seem to find anyone selling anything similar...

Hi All

So a friend accidently blew this amp up due to a short in his speaker cabling, Upon inspection it uses BUZ900P and BUZ905P outputs, this amp had been worked on before because the transistors had been changed before and they did not look original.

Finding a schematic for this amp is near impossible, although i managed to find a shcematic for the A2 which is similar.

Anyway i gave the amp a good going over, all new electrolytics, new emmiters (as one had been taken out). I luckily had some spare buz900ps to test the amp.

Now with the original 900P/905P It worked with no issues, i could adjust the idle current/bias to 60mv (across the emmiters) and above i had it playing for hours. My friend decided he wanted all new outputs as the original ones were a mismatch and had been replaced in the past.

I decided based on research to use Exicon ECX10P20R/10N20R outputs. I used a device to measure them and match them best i could.

To make sure they were fine i did one channel at a time, here is my issue. With one channel running 10P20R/10N20R and the other with BUZ900/905 it worked without issues.

As soon as i replaced all the outputs on both channels to exicons i get a low level hum from the speakers and output if i try and adjust the idle current over 40mv?

The only way to stop the hum is to have it running at say 35-40mv, if i got higher i get an annoying hum from the speakers. At first i thought i had damaged something so checking voltages showed nothing bad.

I replaced the outputs back to the buz900/905s and no issues or hum.

So my question is what is going on? i have a few ideas.

1. Could have an issue with the new mosfets? maybe one or two are faulty
2. They are not matched for the amp and not a good replacement choice?
3. Perhaps the gate voltages are different and the driver transistors need to be updated to match the new outputs?

I could leave it at 40mv but then its not running at class A and i really want to get this running as it should. Any advice or tips would be appreciated.

Thanks

Hi,

I’m hoping someone may be able to correctly identify the pictured transformer.

It’s fitted to a 20 year old Croft Vitale valve preamplifier which is showing short circuit across one of the secondaries and blows the 500ma internal fuse.

The part number shown on the front returns zero in Google search and unfortunately the genius and ever helpful Glenn Croft is no longer with us. The closest in size and value I’m able to find is a vintage RS components 207-144 available on EBay for around £20. Would this be a suitable replacement ?

Any advice gratefully received.

David.

What is better Sound improve led or diode ?

I know there is very little for the subjective on this forum but I am experiencing a strange phenomenon. I operate a 2.1 desktop system. Over time I have replaced the satellites with increasingly large bookshelf speakers. The intention was to make the 8" sub optional (I live in an apartment. I have neighbours).

Long story short . . . my latest satellites are 2-way with 6.5" woofers. They sounded awful, boxy and shallow . . . until today. Today they came to life. For the first time ever the neighbours banged on the wall when the sub was off.

I can only consider 2 variables. 1: (Me), but my neighbours have acknowledged the change in bass response. 2: Atmospheric conditions, temperatures are 10 centigrade lower than 3 days ago.

Was buying passive probe for an old LeCroy oscilloscope I acquired.
Going through the manuals I narrowed down 2 probe models that seems to be default setup to the oscilloscope model.
One thing I am confused is regarding a tip right next to the BNC connector on the probe. Is this tip auto-retracting and would just slip into probe when connected to channel input, some sort of ground pin? Or is it pin specific to newer models? Or is it designed to just touch the oscilloscope case when probe attached for maybe reference ground or something, but I think that should be done by the cable shield in the BNC cable?

The pin is highlighted in the picture below.

Tried contacting LeCroy but I have to make an account first, and the account has not been processed by their sales after few days.

P3A is my favourite amplifier of this class ... i have designed my own pcb ... did a few things on it ... and this become my favourite amplifier and a standard to listen for almost 3 years now together with a diy nearfield monitors 6.5" visaton +vifa ...

I repair give or take around 200 amplifiers per year so i thought since except scopes loads and generators i also want to listen to the amps i repair i normally hook them up to my system and listen from them a few hours

Since i have a few standards created from my setup while listening most of the time my amplifier from the same tuner ( same radio station ) the same cd player and for reference always the same music for more than three years now. In this post i would like to provide some information about the amplifiers i repair may be start some questions about them and listen to others opinions but as a base i will use my listening expirience from the P3...always regarding sound qualities and never power

P3A construction and set up
dual mono 250W trafo per channel 2x28AC
psu caps 2x10.000 mfd on board
MKT input cap 4.7 mfd bypassed with 100nf mika
350 pf silver mica input filter
LTP matched pair +thermal junction
VBE attached in pos driver
82pf styroflex miller cap for VAS
100 PF multileyer cap on the driver
multiturn
120ma biass
BD139-140 family for drivers +VAS ( philps )
outpouts are MJL1302A 3281A motorola originall ( zeck replacement sets )


i normally listen from a passive shunt relay source selector with Alps blue line 47K so most of my tests do not include crosstalk issues since this configuration is almost unbeatable and since i am in the comercial bussines and most of the amplifiers i repair are comercial Japanese amplifiers there is actually no point to try to compaire the one with the other ....

Questions are about sonics, colourations ,ends , how deep , how clear , how crisp, and goes on and on

Most of the amplifiers i repair include tone controls so still comparsion is not that fair but lets thing of defeat switches where ever they exist...

here is a few things i have to say for my amplifier as made that will be followed of a few scope readings and then i will start posting the things i have seen in the amplifiers i repair ...

I will try to post as many details possible about these amplifiers and feel free to email me i f you have any questions or schematic requests

the P3A as is together with the Visaton/ Vifa near filed monitors become a bit endy ...means that this set has absolutelly no problem to deliver low frequencies or high frequencies....Bass is plenty extending often to very low frequency without any problems without anything excecive , punchy and tight but delicate... midle and soundstage are very very present but extremelly balanced and vocals or strings are very pleasent with the slightest sign of distortion and with a lot of depth .... sound stage is so perfect that can provide the placing of the vocals on stage easilly ... now high is one of the most nice since no matter how many remain crystal clean and extremelly detailed at various types of music ...

i t seems that the particular setup will deliver exactly what the producer had in mind ...negatives are that the all system performance has slight U eq performance meaning that midle is a click lower ...but just a clik...

then again it seems that if you play a terrible production the amplifier will make it even worst ...that i cannot explain if right or wrong ...The impression i have is that the amplifier is way too free with no llimmitations of any kind and under this ...sounds logic

thanks for listening ...here we go ...scope readings

Hi guys, we refurbished an amplifier built by Audio Note kit 1 with 300b end tubes and by measuring the primary/secondary voltage ratio resulted for the 4 ohm output a ratio of 25 and for 8 ohm a ratio of 17.5 both corresponding to a Z=2.5K but THD>5% for 6.5w. Replacing the load resistor with 8 Ohm and 16 Ohm respectively yields Z=5K and THD<3% also at 6.5W. Did Audio Note erroneously show that the outputs are on 4-8 ohm, what do you think?

I have doubts:

here the temperature varies 33-35C

1) I have AA NI-MH 2600mah batteries from Toshiba, I contacted the manufacturer and he said that there is no problem with the battery life if you store 0% or 100% the reduction in battery life only occurs when recharging

2) the original Toshiba charger does not have a percentage display so I charged all AA Ni-MH 2600mah Toshiba batteries to 100% and I stored them at the temperature I mentioned, I would need to recharge them after how many days or months without harming life battery usage?

3) I have Chinese Nokia BP-5L and original Xiaomi BM20 batteries, I charged them all to 3.8v and stored them at this temperature of 33-35C, after 6 months I saw that their charge dropped a little to 3.78v, which Would it be a longer and safer period of time to charge all of them without compromising their useful life?

I won't lie, most of the time when i built DIY audio stuff, i'm blindly following ready made schematics. So i did 20 years ago when building my 2sk170 PrePre and the following RIAA stage. Now, over the years i have gathered crates full of electronic components stuff, often MIL spec parts, which i wanted to use some day to rebuild things that actually work, but have some flaws, maybe only optical, sometimes it was just me modifying into a wrong direction because i didn't have parts at hand, no money or whatsoever.

Now the time has come, the amount of parts in my garage is getting annoying. So i decided to "build it away" and get my final stereo setup done.
One of the DIY devices that has a flaw is the PSU of my phono amp. It humms a little bit. It is basically only LM7824/LM7812 with some filtering caps. So i thought to myself i had to go look into the crates what i have.
What i found is a nice little Collins choke with 2,5H/100R at 0,11A. I thought it could be a good idea to use it with a decent 30V toroid, some 4,7mF caps and two LM317 regulators for creating a dual power supply. The needed voltages are +12V@40mA and +24V@60mA.

I turned on PSU designer to simulate that and... wow... i'm getting 30V @ 1,4mV of ripple only? Can that be correct? I mean plus the additional rejection of the LM317s which should be around 60dB for each stage that should make a very quiet phono PSU in the nanoVolts region right?
Now what i would do is adding a LM317 stage to regulate for 24V for the MM stage (approx 60mA) and behind it another LM317 to regulate for 12V for the MC stage (approx 40mA). Maybe add another RC in front of the second LM 317. Should take off some heat from the reg's shoulders and should reduce ripple even more. Maybe something like 20R with 4,7mF or so.



Ok, so i'm not the smartest guy when it comes to designing circuits (and living with women). So i have some basic questions.
Everyone is building shunt regulated PSUs etc. No doubt they work good, but for me they are hard to understand and build. If i interpret PSU designer correctly, i wouldn't need more than these few parts plus etching a little PCB for regulators etc to get away with it? Does that mean all the effort put in shunts, low noise regs, huge filter caps etc is only for cost reasons because of rather expensive chokes? I mean actually you can get a choke with these values around USD 10 to 20 used or so. Can this be true?

Also another basic question: I would like to build a test setup. Do i have to worry inrush current could destroy the choke? Maybe should i add a current limiting resistor?

Thanks for your help!

OMG I have so much crap in boxes. Projects, projects, dreams and failures and more projects..
somehow never the exact part.. hello Mouser. Goodbye $$.
I cannot live long enough to use or learn how to use it all up!!
oh well. better to join up here and learn and see what others actually accomplish 🙂
43 Years as a Tech. About 35 of those years suxed, lol. Should have stayed in the New England area,

73's AE5ZN

DYI Audio folks

I have built a point-to-point version of Tubelab's SPP amp and had some difficulty understanding how the bias of the phase splitter section of the 12AT7 works. When first built, using the specified value 75K resistor as R106, the grid voltage on pin 2 was a couple of volts higher than the Cathode voltage on pin 3. For example, 72.2v on pin 2 and 70.6v on pin 3, when B+ is around 280v. I changed R106 to 150K ohms, which nicely turned this difference around. This approach was a suggestion by rknize on the SPP thread in the Vendor's forum. FWIW, I'm using new reissue Mullard 12AT7s

Is there a simple explanation for how this splitter is biased that anyone can offer, or refer me to, that would explain how the tube is biased and why changing the 75K resistor to 150K worked, and whether that's the best resolution of my bias issue? Thanks in advance for any assistance on this.

Simon

Hello I’m looking for the schematics of my Nu- Vista M3. Could you please share it with me?

Hello everybody!

I am a new member in this forum, and newbie in DIY Audio too. I just started learning about hardware, audio components 5 months ago, and this forum is a very big school for me 🙂.
I am a fan of Nelson Pass and now trying to complete Aleph-M amplifier. Sorry about using your schematic @@.

Thanks you.

Hi everyone,

I will start this off by saying I found this forum via a bit of googling but everything y'all are talking about is well above my pay grade. It's like reading a foreign language. That said, this seems like the place to ask, so I figure I'll do so - I am basically trying to see if the modifications/build I am thinking of is even possible - not "affordable," "optimal," or even "sensible," but possible.

I have a 1970s Peavey bass amp. I love the tone I get from Channel A to death. I don't necessarily care about Channel B or the combined two channels. There is a pedal manufacturer who makes a pedal replicating Channel A, and I may buy one at some point in the future. However, these amps are currently a dime a dozen, I think I paid a hundred dollars for mine and less functional ones that have been stripped for parts are even cheaper.

Being a 1970s Peavey, it has a number of drawbacks - it's 2 feet long by 1 foot high by 8 inches deep, it weighs about forty pounds, and even at that size it's 130W RMS. It has 1/4" jacks rather than Speakon outputs, and it has no balanced/XLR output to run to a board or front of house.

Now, the sensible thing to do here is to get a small class D amp that has these features and run it through the effects loop, and indeed I have done this with some success in the past. But I don't like carrying around multiple amps and having to hook things up. I want it to be in one package, and having something totally different than everyone else appeals to me.

So - is it possible to build a single, elegant solution, combining the preamp from Channel A with a lighter, louder, class D power amp (ICEPower or the like)? Can this be done for a price that does not rival that of a used car? Is this just insanely stupid and not at all worth pursuing? Assuming the answer to the last question is "no," who, if anyone does this kind of work? I mean, in theory I could, but given that I don't even know how to read a schematic I'm not sure it's a project I'd like to tackle.

Cheers!

Aim; I want to have more capacitance

Some info

1. Only board1 has a rectifier bridge. This means AC is only going Too this board.
2. board2 (± V and ground pins on the missing rectifier) is connected to the corresponding locations in board1 immediately after the bridged rectifier
3. The boards are on top on each other using hex spacers.
4. This is what the input looks like.




Would it work? I thought of having rectifiers on both boards and then they share the transformer secondaries but I read that's bad idea.

Thanks for the help.

Acquired a Technics 1200 MK2 that won't turn on. I took the platter and plastic cover off to take a look. Right away noticed there was what I assume to be magic juice residue in the well that that the power transformer sits in. No external evidence of liquid spill or anything of the like.

I plugged in to see if I could do some basic testing as far as I might understand. I measured where the power cable leads plug in and got 120V AC, then again the two red wires that run into the transformer case. Again got 120V AC. Then measured the two yellow wires that plug into the mainboard, got 0V AC. Would this indicate a dead transformer?

Just want to be somewhat sure before I go ahead with an order for a replacement transformer assembly, which comes with power cord, power input board, and transformer..

I have been a reader / lurker for a long time and have not posted before. Lately I have been consuming all the content I can read on dipole and open baffles. I have never listened to a set of open baffle dipoles, and enjoy the thought of building my own this year.

Hello, I'm enjoying the speaker diy in Korea
I set my nationality to South Korea in my personal information, but the flag does not appear next to my nickname
Is there no Korean flag on the diy audio site?

Okay, I am about to buy my first ever rack crossover and am torn between two Behringer models, the CX2310 V2 or the CX3400 V2

https://www.behringer.com/product.html?modelCode=P0CCS
https://www.thomann.de/gb/behringer_cx2310_v2.htm

https://www.behringer.com/product.html?modelCode=P0CCT
https://www.thomann.de/ie/behringer_cx3400_super_x_pro_v2.htm

I plan to split it in 2 only, running 2 18" subwoofers and 2 full range 15" + tweeters. Low and high respectively.
I do like the extra features on the 3400 but it does seem a little more complex to set up and "tune" than the 2310.

Which one would you pick.... And why......?



/DATABASS

Anyone have a cross reference for these? Saw original power supply devices were 3205. Can I use the same mosfet with 47 ohm gate resistors?

Hey guys here with an another project. Rockford fosgate punch power 50x2. Problem no audio from left right channel. Right channel has audio but is muffled and weak. There’s a few discolored resistors near mpsa06 & mpsa56. I’m not to familiar with this design. Any pointers?

How does this look:

Tweeter: Moreli 308
Mid 4: SB Acoustics SB12MNRX2-25-04
Woofer 8: SB Acoustics SB23MFCL45-8, 8

Design goal: 3/4 way tower (sub below 60hz) towers for $600 ish.
Active XO Sealed Towers.
Thanks!

I was hoping I could get some opinions on this Adcom 5800 restoration kit. Cost is stated at 295.00 (make an offer).

https://www.ebay.com/itm/1656357443...jyrKVaT2T3usOX53luZLTpFOsQ==|tkp:BFBMpJL6v-pi

It does not seem a super far-fetched price for everything that is included, just in my opinion, and of course it would be a timesaver in-regards to having everything in one package instead of researching everything myself, and searching out all of the part numbers, parts, etc.

The one thing that I do question is the kit has 22000uF capacitors instead of the 24000uF is that came stock in the unit. I also inquired if the transistors are hand matched, and the seller stated they were not. I had looked up for a replacement 24000uF capacitor, and I could not find any around that appear that they would work and the seller said that is one of the reasons he dropped the capacitor, micro farad range down to the 22.

I have placed the description from the seller of the kit below in case people rather read it here than searching through the eBay ad itself.

Any opinions, thoughts, etc. on if this kit seems to be worthwhile would be greatly appreciated. Thank you very much for your time.

Description from eBay item:
The scarcity of good, honest techs who can do good and reasonably priced restoration/rebuild of audio equipment inspired me to create this restoration kit. In today's day and age, it is difficult to find a knowledgeable technician who can service your audio gear properly. I have seen many poor quality restorations of equipment that cost way too much for their owners. In 99% of the cases, only a few parts were replaced, instead of a full and proper restoration job.

A proper restoration must replace all electrolytic capacitors on all boards. Do not fall for partial kits that restore just one PCB (power supply, power amp, etc.). This is not a good or proper way to restore your audio equipment. It is the same as with car tires; one should never replace just one tire and keep the other worn-out tires on. A proper rebuild requires a full recap of all PCBs.

On the other hand, if one succeeds in finding a good tech, the wait time is usually 6-12 months for the unit to be serviced, and costs are sky-high. I have been servicing audio equipment for many years and have developed deep respect for all good equipment. Knowing how amazing and warm these units can sound, I decided to put together this kit. It includes very good upgrades and improvements that must be done to the unit. This restoration kit will make a huge difference in the sound quality. All the parts are of high-quality Japanese Nichicon / Rubycon / IC / United Chemi capacitors.

I am extremely particular about the quality of the parts provided in this kit. Knowing how many bogus/fake caps, diodes, resistors, etc. are out there, I source all the parts from reputable wholesalers and buy them in bulk.

Vintage audio equipment has the potential to deliver rich and authentic sound when it is properly restored. Not only can it enhance your listening experience, but it can also evoke memories and bring joy to your life. Let's work together to bring your vintage gear back to its full potential, and make sure you have the music you deserve.

Greetings friends. I've put together a small power amplifier around a pair of PCBs sold as Dynaco 6V6 Push-Pull Amp:



This is my first Push-Pull build, and a bit of a Shoebox build, as I already had the power transformer. It has a pair of windings for HV and LV, so each channel has its own dedicated power supply:

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I got it all hooked up and the voltages looked good, they're written in red in the diagram above. Hooked up a pair of speakers, and got nothing. Well, a tiny, tiny bit of very distorted signal out of the left channel when I open the volume pot all the way. There is a 100k Log pot on the input as a volume control I forgot to draw in there. Is that 10k input resistor too big? Is this thing meant to be fed a much larger input signal from a Preamp or such? I've no experience with the floating paraphrase - is the cathode bypass cap meant to be polarized?

I'm getting no hum or buzz at all, just a tiny bit of signal coming thru. And when I touch the meter probe to pins 1 and 6 on the preamp tubes, I get very clear taps coming thru the speakers. Voltages look right - what am I missing? should I bypass that pot on the frond end and see what I get, then reduce that input resistor to 1k or less?

thanks!

will

Hi, theres is a chance to get the service manual for Sansui AU-X901 ? thanks

4 boxes for open baffle subwoofer. Cut for the Seas L26RO4Y driver (for adding subs to LxMini).

Two painted, two unpainted.

$30 for one, or $100 for all four.

Pickup in Sacramento (or in SF/on the way but that will be in a few weeks

Thanks

S

WTB 1steropair F3 pcb.

Hi

I have a 4x10 HD in good condition with original boxes and power cable, no remote. Available for local pickup in San Francisco, or Sacramento or anywhere in between.

$300 + Shipping.

Thanks

Shri

I used to use a Creative Sound Blaster X3 connected to a set of Logitech z607 5.1 speakers for my PC, which I converted into an all-in-one entertainment system in my lounge room including using it for TV and a home theater, and the bass redirection passed sound 80hz and lower from all 5 satellite speakers to my sub. I went to my onboard Realtek on my B550 MoBo because it has loudness equalization for gaming which my Sound Blaster X3 does not. The problem is its bass management only works for the front left and front right speakers and not for my center, rear left, and rear right. I hooked up my SB X3 again only to find a Windows update that happened in the meantime has broken bass redirection completely. Is there a program free or paid (as long as it's not a monthly or yearly subscription) that would allow me to have bass redirection from all 5 speakers globally with LFE gain included, so I can disable it in my Gigabyte Realtek audio panel and use said program? An example of my conundrum is the DOS game Exhumed, running through the Raze source port, that supports surround sound. When I open a door in front of me I hear the bass as the sound of grinding stone is heard in front of me, but when the door closes behind me the sound is flat and quiet, even when I set the front speakers to -10dB and the rear speakers to +10dB. My sub is set to +5dB.

To start, if you're aware of other threads/links on this subject please feel free to reference.

Backstory: Since joining this forum years ago and learning hornresp, I've played around with hundreds of combinations of subwoofer designs and speakers in hornresp and it has become one of my favorite ways to burn time. It's not uncommon for me to see a driver, lookup the T/S parameters, plug into hornresp and see if I can make a box with the flattest response curve between 40-100hz.

Example: Eminence Legend BP 102 in a ported box vs TH smoothed with a 2mh inductor in series



When I swap out the Eminence Legend driver with a JBL GT5-10D, everything goes crazy:



There doesn't seem to be much I can do with the TH dimensions in the GT5-10D to flatten it out. Therefore it seems this driver just isn't suitable for a TH unless I'm really doing something wrong here (I do want to know).

If this is not a mistake on my part, I'd really like to understand why this is happening.

I'd also like to hear any opinions on using the Legend BP 102 in a TH. These dimensions seem very reasonable and easy to build, especially if I build a TH with only one turn. I'm not concerned with maximum power (I see it will reach xmax with ~50 watts), just something with good response that is not too big and easy to build.

Settings for the Legend BP 102TH:


Bass reflex:



Settings for JBL GT5-10D TH:


Bass reflex:

Hi,

I found an old "Digitech AA0505" 75WRMS stereo amp in the garage.
I was gifted this years ago and recall it always suffered from distortion.

I'd like to have a go at repairing this but I have not been able to find a circuit diagram on the 'net.

Any assistance or hints where to start would be gratefully received.

Cheers
DMonds

Why the modern audio amplifiers, dont have Bass, Treble, balance
What is the alternative they are using?
Just like Onkyo M-5010

Equalizers are also vanished.

As I know, the main difference consist on the enclosure resp. cabinet version. But maybe there are additional differences on the electrical parts.
Because on the web I have found only information concerning the "LE" version I also think it is possible that this model "750" was only manufactured and thus only available as an "LE" version.
Thank you for clarify.
P.S.: A friend of me want to replace the drivers for bass-Midrange and dome tweeter because the voice coils don't longer work in the right manner.
Which currently available drivers are close to those from genuine used ?
Thank you for an advice.

Here a review from the "LE" version
https://www.tnt-audio.com/casse/miss750e.html

As per the title. Bought for a speaker project (pictured in my other for sale ads and below). Price is £300 including UK shipping.

I am having trouble making my first post, I was going to do so in the introductions section, but could not type in the body section only the title.

I hate smd, and found these in my stash. This is what is offered:
2SK209-gr jfet 100pc
2SK2145-gr dual jfet 10pc
BSH111 mos 8pc
BSP129 mos 37pc

How about $40 for all? Including shipping in cont US.

I've had some diy floor standing speakers hanging around for quite a while, something I had to buy to get something else and have now decided to do something about them.

They have 2X Seas P21REX drivers per speakers and an Audax 25DT tweeter installed between them, the crossover I'm sure isn't correct as it just has a coil and capacitor installed, nothing else!

I'm sure some design must have been followed when building them can anyone shine a light on possible crossover designs etc?

It's been a long time since I posted here and I hope I'm not breaking a rule.
I have some unpopulated boards I made with a friend back in 2008 that I thought maybe some could make use of. I need to actually get a count of how many I have but there's a small quantity. Maybe 10 or 20.

They're setup to biamp a single speaker so there's four LM3886's to drive a woofer and then a single LM3886 to drive a tweeter.
They also have an optional crossover which, I think is a linkwitz-riley style and there's both a 12dB and 24dB. If that's not wanted there's pads for an RCA input jack directly into each amp.

I used a pair of these for many years until I finally gave them to a friend a few years ago. As far as I know, they're still working.
The board only has one modification which is I had to add a capacitor to the single LM3886 circuit, I think in the feedback loop to drop the DC offset as I was using it to directly drive a tweeter. The four LM3886's with the so called "servos" seemed to work beautifully on the two I built.

They were originally intended to be bolted onto the original rear panels of powdered advent speakers, but I also had plans to use them as stand alone amplifiers as well, it just never happened.

Anyone interested?

Hi All,

I’m looking to replace a .22R dual emitter resistor for a dynacord powermate 600 That has gone into protect mode.
1, 5w 0.22ohmn JX2

I’m Having bother finding one.

Is there a substitute I could use please?

I have confirmed 10 faulty components so far on one channel. The other channel is ok.

Thanks in advance

I am using my WiiM Pro in combination with other Linkplay products.
With the Linkplay modules (as implemented by Arylic/Up2Stream) , I am used to change the SSID naming by using UART passthrough software.

Question

1. Can I use the same software to change the default WiiM Pro SSID name into my own?
2. What command string should I use to do this?

Hi! Everybody knows Cirrus Logic DACs CS43131 and CS43198. Once I noticed a discrepancy between the sound of my CS43131 and its measurements. After some research, I came to the conclusion that its brilliant results are fake. I have not any source with CS43198, so it would be interesting if someone checked my findings with it.

Fake 1. 352kHz and 384kHz support
Both chips accept such streams, but few people noticed the fixed setting of digital filters for these modes: 0.263Fs. In other words, frequencies above 92.8/101kHz will not be played at all.

Fake 2. Noise I (THD+N)
The noise floor in wideband measurements, which is also rarely used, has a steep rise above 40 kHz.
On the FFT, the signal harmonic bases are more wide compared to, for example, es9038q2m.
I'm not an expert, just an advanced user. If this is not a consequence of active noise shaping, then at least it looks that way. That is, the real THD+N should be noticeably worse.

Fake 3. Noise II (DR)
According to the standard test, CS43131 shows a DR of at least 130dB(A), similar to good professional chips. It was unclear why I couldn't hear it. The following test was carried out. A 30kHz@0dB signal was mixed into the standard 1kHz@-60dB. 30kHz is far enough from the [20Hz-20000kHz] range so as not to interfere with the measurement too much.
Result DR=129.8dB(A)

The noise floor rose by almost 20dB!
Result DR=110.3dB(A)
This confirms the rumors about variable gain, I suppose.

I very briefly repeated this test on the ES9038Q2M to avoid an error.
Result DR=122.8dB(A)

Result DR=120.9dB(A)
In general, there is no difference of 20dB here.

Logic of Currus
Of course, I can't know it for sure. I believe the dynamic gain is needed for outstanding DR. The noise shaping helps to improve THD+N measurement. And the huge noise hump is reduced by a non-switchable filter. I don't want to blame the CS developers for anything. I just don't think the CS43131 is a high quality HiFi chip.


PS Many thanks to IVX for exellent equipment!

Hello.
I have theese dipped silver micas, 300v most are 1 % , there is 3 kilos, I would like to sell them as lot.
I have no idea about how many, but it's on the other side of 1000.
Was thinking 300 euro .
33pf 84.5pf 130pf 160pf 174pf 177pf 270pf 280pf 316pf 330pf 354pf 372pf 378pf 470pf 632pf 1120pf
1240pf 2920pf 1480pf 1500pf 4005pf 4008pf 4300pf 4340pf 4540pf 4860pf 4990pf 5500pf.

George's most recent advice is that the power transformer should be 700VCT (350-0-350). Looking at Hammond's potted offerings I see the 373XP rated at 700VCT @ 127mA:

• 5V/2A - this would tie me to the 5AR4 rectifier tube @1.9mA heater current but that's not a big deal to me.*
• 6.3V/4A - this should be sufficient: 2xKT88 =3.2A, 1x12AT7 =0.3A, Total 3.5A Other output tubes (EL34, KT66, etc) would need even less heater current.

Does anyone see a problem or caution with this?

Hammond 373XP

* Edit: Some other rectifier tubes run on 2A heater current but that would be right at the transformer max with no margin.

I would like to refurbish four subwoofers. Each was previously were outfitted with a class-AB plate amp, which unfortunately is terrible. I powered the plate amps from a 300VA transformer that has dual 45Vac secondaries, which translates to an unloaded DC secondary of about 63V, and I would like to re-use them (there is one in each subwoofer box). I would like to remove the remaining amp guts, re-build the power supply, retain that large heat sink from the old AB amp and mount the new amp module to it. I have lots of 100V can style caps that I can use to make a beefy linear power supply. I'm just looking for an amp module to work at this rail voltage. I would prefer not to add other DC driver voltages if possible, although I would consider that. The drivers will be 4R nominal 12" subwoofers.

I would like to keep the cost at or below $200 per amp module and am looking for at least 250W@4R. Perhaps there is an older ICEpower or UCD module (e.g. UCD400) that would be good when only used for subwoofer duty?

Other suggestions welcome!

Frist time trying replacing ferro fluid on old 1" soft dome tweeter and seek kind advice from experienced members.

When I google, there are several different ul (microliter) such as 100, 300, 650, 900ul. If I replace 1 inch dome tweeter, do I just need 100 microliter per each 1 inch dome tweeter? It looks like 300 ul is the most popular one from the number of units sold somehow.

And, how much filling the ferro fluid? My guess is that it is not to fill all the way up since voice coil needs to be going in then it will overflow.
Do I fill about half way and it is about right?

Thank you very much in advance and any advice would be hugely appreciated.

I purchased these with the intent of using them to restore an amplifier I no longer have.

Included in the sale:

20-2SC2326K-AA
20-2SA1016K
4-2SA1207
2-2SA1210
4-2SA970BL

Have a 1970's Quad Sanyo Receiver DC6100K with an early type 12 pin connector on the back -

Does anyone know more about the type of connector and what plug would have been used to marry them together.?!

By the way there is no manual (yet) ....still searching for one...must be one out there somewhere!

Thanks in advance