Hi

I have an Audiolab 8000C pre- amp (older UK model) which has no output from the RH channel. It was fine a few months ago when I last used it and there were no pops bangs etc when I turned it on. The relay clicks as usual and LH channel is fine.

I have had a look at both sides of the board and could see no sign of shorts or components failing.

I note this one is fitted with an sds relais tq2-24v. Anyone know if these cause problems or aware of other common problems ?

Any help would be greatly appreciated

Ale M reviewed the ETracer on his website, EML 20-AM DHT curves and model – Bartola(R) Valves

The fellow who designed the Etracer, Chris Chang, has several videos on how it operates:

Video

Quick question for you guys. I was wondering if anyone knows if there are any DAC chips with the same (or similar) pinout / size as the Burr Brown PCM58P?

I've been looking around for a while now, but the chip seems old enough that most of the information has disappeared.

I'd like to replace this chip in a piece of equipment and perhaps get something more modern, perhaps up to 24/192.

Is this something anyone has done or am I being a dumbass?

Hi

someone can help me to find the manual of 118A?
I have a service manual but not the user.

Thanks

Walter

I am arm wrestling with a stubborn hiss (5mVac measured at speaker terminal). When the driver tube is removed, the hiss is eliminated. I have tried several grid stoppers (1K thru 330K) and none seem to have any effect.

I have tried shielding the tube without any success. Hiss.

I tried replacing the IT with a plate choke Cap/resistor coupling. Still, hiss.

Hiss is certainly coming from the Aa tube. And yes, I am aware that the Aa is not a good match with the 5K IT, but I am just trying to get the feel for the Aa.

Any thoughts?

The resistor came out of a Vandersteen 3A crossover (see attached pictures). I got the color code off it, but I don't know what value it is. It's bigger than the 3W resistors I have, but 2Mohm 5W resistor turns up no axial parts on Mouser, so I wondered if maybe I was barking up the wrong tree. I've posted on the Vandersteen forums, but if they don't come back with an answer, is there any way to figure out the appropriate value?

Hello all,

I'm looking for National Panasonic/Technics rotary selector knobs, the ones seen at the rightmost part of the amplifier...

This is a barn find, it was missing those two knobs and sincerely it doesn't look as good with different knobs ar all...

Who knows, maybe someone has this in a box of parts and would be willing to sell/exchange them

Thanks in advance!

Hi everyone! My first time posting here. I believe no one has ever posted about the difference between the stock output transformer of the TU-8900 and the Lundahl LL2785B, so I thought posting a thread about it could help someone in the market looking to get his first 300B amp and having a dilemma.

About a month ago, I was about to order the TU-8900 with Lundahls already from Victor and we've been exchanging emails about it. I know, most of you won't believe this, but the next day, a package arrived on my porch. It was a TU-8900! My wife just started her new job about two months ago and she asked me what do I want her to get me when she receives her first pay check. I said, a 300B would be nice! She wasn't kidding! I was so excited, but she didn't know about the Lundahl output transformers. And that's fine.

I proceeded and built the amp. It was my first Elekit, but I'm not new to diy stuff. It came with EH 300B tubes and Clear Top 12AU7s. Also ordered VCaps for it as well. I knew it requires a lot of time to burn in before I can really judge it, but I had to get the Cossor WE300B from Victor. They came in quick and replaced the EH. Right off the bat, the sound is more pleasing to me.

I gave it about 80 hours and I just couldn't stop thinking about the Lundahls. I emailed Victor and ordered the Lundahl LL2785B. Oh boy, it came so fast! He shipped it Monday and I received it Tuesday at 3:30 PM. Installed them and I was speechless, literally, on what I heard. The LL2785Bs are just next level in performance. And yes, I know it's too early to judge them still (I have only about 20 hours on them), but it's very good sounding. I'm not saying that the stock transformers are bad, especially if this is your first 300B amp (the case for me), but the Lundahls are more musical than the stock. Almost more of everything. The three biggest differences for me are wider soundstage, more 3D sounding (I can hear some instruments like they were coming from the back of my seat), more detailed, and the bass is so much better!

I will continue to burn them in as the Vcaps requires about 300-400 hours (based on what I've read) and I will post my impressions here later.

I believe that I need a LF transformer for my 1+1s, would prefer MK-121-C Red Medallion but am willing to use what I can get.

I've managed to blow (or break the flyout leads) of one so looking to replace. Scan-speak 18W-8546-01

Really annoying as they are in a wilmslow kit speaker with Scan 9300 tweeter and a load of Hovland crossover caps and after many crossover tweaks I really like them.



There's no Uk stock anywhere new and the only place I know that winds voicecoils in the UK has now stopped repairs and closed its doors.



Alternatievly does anybody repair/rebuild in UK/europe?

I have a pair of these that are used and I’m unlikely to ever build a 300B PSE now as I've gone down the path of big power hungry speakers. I’ve had them sat in a cupboard for 8 years since being bought used!
I don’t post much on hi-fi forums recently but have been a member here for years.

Datasheet here: - SE12 SINGLE ENDED OUTPUT TRANSFORMER 8

They’re BIG! Pint Glass for scale in pic. And Jolly heavy at 6.2KG each. I’m not sure about posting them TBH.

Current RRP is £737 delivered.

I’d like £350 + delivery or collection from UK surrey/hampshire border.


http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE6.jpg
http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE5.jpg
http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE4-rotated.jpg
http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE3-rotated.jpg
http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE2-rotated.jpg
http://www.gt400.co.uk/wp-content/uploads/2021/04/Sowter-SE12S-300b-PSE1-rotated.jpg

Hi,

I know its not exactly HiFi, but I am considering using a professional AV switcher as a way of increasing amplifier inputs.

In particular an Extron MPS112 - this will give me 12 additional inputs and the specs don't seem too awful (0.08%THD+N at 1kHz, 90dB S/N), compared to the cassette decks and 8-tracks that will be plugged in to it.

These are cheap on ebay and a lot cheaper than the diy solution I was planning.

It seems like a pretty good solution to me, but I haven't found much online about anyone using these for audio, which could be a bad sign.

Has anyone else used something like this? What was your experience?

Thanks, Jon

Anyone know idle power consumption of the various class D modules?

The only number I've seen is for this one

http://www.ebay.com/itm/2pcs-L20D-I...ltDomain_0&hash=item2c5dafb004#ht_7538wt_1258

"Total Idle Power Consumption 7W No input signal".

Doesn't sound like much but it adds up with 14 ch.

Question is, do they actually do anything useful aside from protect the dome.. In other words is it all a snake oil description for a dome cover. I have read in various places now that removing them can be beneficial..?

Hi All. I'm going to ship these in a USPS Priority mail flat rate box. This is all I have time for - therefore it's to the US only.

You can stumble upon these on Ebay (I see ONE now for $250!) or you can get them from Mouser (at least $500 each - hard to tell). Made in Andover MA.

These are 28V DC SMPS that have isolated outputs. You can run them in series for +/- 28v. They are trimmable to reduce output voltage if desired. Look to the Vicor website. You do lose efficiency when you trim them. I run a similar pair in an external chassis to my Pass M2 clone. The results please ME These Flatpacs seem to not mind capacitance on the output terminals, although you probably don't need much.

Pictured they are in series, with ~14ohm between the ~0v and +56v. They are doing ~4A with them in series. Another meter sits at ~28V at the output on one of them.

They are highly regulated and in my reading I gather that the switching frequency increases with load <this is from memory.

Of course these are not made for audio, but for industrial applications so really it's a chance, but if you've been looking to try them here you go.

Not sure what I paid for them, but let's go with $75 (from $120) shipped for them both. Paypal friends and family would be great.

Hi There!

I'm looking at making some desktop monitors for my office and have been considering one of these seemingly great full range plans: the .53 Karlsonator, the XKI and the folded TABAQ (have I missed any others??).

I'm getting a little lost though on which speaker I should be considering/choose. Part of me thinks I should try and find a driver that works in ALL of these designs and just give them all a go.

I'll be supporting whichever speaker I choose with a Wharfedale SW150 subwoofer for low end extension, so digging as deep as possible isn't really my goal. 60-70Hz f3 would be more than enough though if it doesn't affect mid/highs then going deeper isn't a problem either.

I'm hoping to only spend $150 USD or so on drivers as a maximum.
I'm in Australia so availability isn't a huge issue, but drivers can be pretty expensive here. For example Dayton PA130-8's are $40 USD each here. I'd probably prefer a 4" or 3" driver though for more high end extension. I might also be able to find an economical way to ship smaller drivers from overseas and get a lot more bang for my buck (stupid convict tax ~ it's an Aussie thing).

I'll be listening to these in the nearfield, maybe 80cm - 100cm away from my ears but 1.5m apart from each other. Max SPL is not a problem and I don't need to fill a large room. I will be placing them on my desk or on stands on my desk and they'll be about 15-20cm from a wall.

Bit of a comparison:

0.4x Karlsonator - Faital Pro 3FE25 Driver - 60Hz f3, 83dB SPL, 310mm H x 175mm D x 175mm W.
0.5x Karlsonator - Dayton PA130-8 Driver - 60Hz f3, 87-88dB SPL, 385mm H x 203.2mm D x 298.5mm W

XKi - W5-2143 - 60hz f3? - 91dB SPL - 320ish mm H x 274ish mm D x 223ish mm W (Apparently a very good driver).

3" Tabaq Folded - 65Hz f3 - 85 dB SPL - 272mm H x 226mm D x 144mm W

What I don't really have is a comparison of sound quality between the designs!
So if anyone has any ideas, driver selection advice, listening impressions or advice to chip in I'd love to hear it. If this thread turns into a great resource for desktop speakers I'd love to see that too. It's not a topic that seems to explicitly get a lot of attention and I feel these small full range designs, tuned for musicality and frequency response, rather than max SPL are perfect candidates for this use case.

Thanks everyone and I'd love to hear from you soon!

Hi all.
I wanted to pass on some trial results from playing around with a Scott 299B to see what is possible with the stock iron. I had done the usual mods to this type of integrated amp from the early 60s that is commonly advised: cap and pot replacements, etc, but was never very impressed with it sonically. This amp were clearly built to a price point and everything is pushed hard to minimize the parts count & cost. So I pulled out all the stops and changed almost everything except the output tube and iron.

I shoehorned a Hammond 159Q 7H/150ma choke in to run the PS as choke input. This got the B+ down to 310V nicely and allowed triode operation of the 7189s. I am running the 7189s at 35ma each as the power transformer is designed to supply ~140ma and I don't think they designed in much of any excess capacity. The stock fixed bias arrangement I kept as it works OK and I didn't want to lose 10-12V of B+ across a big bias resistor. No global feedback at this point.

The driver is a Schmidt cathode coupled type using a 12AX7. This is simple, works well enough and both channels only took an additional 4ma from the B+. All coupling caps, four per channel, are some old Tektronics 0.1uF/600V oilers I have been looking for a project for. Resistors are various wattages of Allen-Bradley carbon comps: nothing fancy.

I pulled the phono section out and all the various crazy filtration they used to put in pre-amps in those days. Volume pots are 100K Bornes. I replaced the tube sockets as well. So stripped to the minimum: 4 7189s, 2 12AX7s and a 5AR4.

This thing is really sweet and much better then I was expecting! For $120 of parts, its improvement has the best cost to performance gain of any mod I have done. If you are sitting on one of these 60s integrated amps(6BQ5, 7189, 7591, etc), the combination of triode strapping and choke input PS is very worthwhile IMO.

Cons? Sure, always are. Top and bottom frequency extension have been sacrificed a bit to get the super sweet midrange. And I don't know how long the PS choke is going to last running LC at 100%. Its started buzzing a good bit after only 50 hours, so it might not be up to this task. Oh yeah... and output power is down to the 5W range. I can get it to crunch on my 94dB speakers at a moderately loud level but it is not as harsh as the clipping was when it was running in pentode. Still very enjoyable to listen to within its power capabilities.

Thats it. Happy soldering!

First of all, this is a project that is _way_ outside my skills, so I have a good dose of blissful ignorance. But sometimes that helps?

Behringer makes a P16 personal monitor system that uses 2 sets of 8 channel AES3-based digital audio over ethernet cable. They have a very capable and physical interface to create a personal mix of the audio. However, I have a couple of wishes:
1. I don't need 16 buttons and a variety of knobs; I want to have it controlled through a touchscreen wirelessly.

2. I want a smaller package.

3. I want it cheaper 😀.

It occurred to me that it _might_ be technically feasible to even use an ESP32 to read in AES 'frames' into a set of DMA FIFO buffers, do matrix operations from the software fader settings, and then pass the audio out through an I2S interface to a headphone.

Because this is for personal monitoring, latency is critical.
At this point, I legitimately don't know if the optimized ESP-DSP libraries are going to be able to keep up with 16 channels of 48khz audio being mixed down to a stereo stream.

Does anyone have any advice? Is there an easier way to do this?

I'm looking to convert an old bass reflex speaker to an infinite baffle box. The simplest way is for me to affix a new front baffle to it but if possible I'd like to be able to remove the new baffle. Would a screw on panel be sufficiently air tight? Could I use a gasket or similar to achieve air tight status? Thanks

Hello All,

I've come into possession of a Melos MA-333, which has a LDR potentiometer (from what I gather these sounded nice but had a ton of reliability issues).

Whomever had this before me took the audio signal from the LDR board and piped it through the Alps pot below the board which was originally used to adjust current to the LDRs and adjust the respective volume (pot was no originally in the audio path).

I've no intention of repairing the board as several PCB traces were cut and it's a bit of a mess. The Alps pot in there now is a 100k motorized Blue Velvet - been trying to find information on how to tear out this board and just replace the potentiometer with a better one (say a TKD for example). I can't quite seem to piece all the information together as some forum members are saying there are some resistor changes I'd have to make in order to switch the board out and run straight to potentiometer (impedance matching?) - doesn't look this was done in the current implementation. The balance pot is also very strange, moving it to either position gives me a distorted left or right channel, not sure what is happening here.

Here's a video of someone who's gone through a restoration of the original volume board and may help provide some guidance to those who's knowledge eclipses mine. It's tough as there are no public schematics for this preamp (or any other of their products). Happy to provide pictures if anyone would like.

Hopefully someone is able to shed some light on what's required to make this happen as the group here has been immeasurably helpful in all of my posts, can't thank everyone enough!

Does anyone have a real BC330 transistor datasheet? Apparently it's a 1970's transistor from Texas Instruments, but it could be that Telefunken also made them, as they are often found in Telefunken equipment.

I'm looking for a datasheet that has some measured data on noise performance - I know it's supposed to be a low noise transistor, but not how low. I have found lists with a few absolute maximum ratings, the h_FE range, sometimes an f_T or c_cb value and the remark that it's meant for low-noise audio stages on the Internet, but I haven't found anything that looks like a real datasheet.

Thanks in advance,
Marcel

I recently found my first esl's, Acoustat 1+1's, and it turns out one of the large low frequency transformers has been arcing for some time and has a burned spot on the windings. I tried using several layers of Corona Dope on it, to no avail. I guess my question is, does anyone know if there is a person who rewinds these if you send them the core? Or does anyone know how to go about getting a replacement? The other speaker sounds amazing and I'd love to get these going, together. Thanks for any leads in this direction

I have friend with a Carver M-500t which puts out what sounds like a dimmer buzz at idle.

After reading the Carver postings here, I've come to the conclusion that it's probably noise from the triac in the Magnetic Field PSU. This can apparently misfire under light load conditions.

Does this cause a buzz at the outputs?

Does anyone know how to fix this?

Hi folks.
Though I'm more into SE Tube amps, I have had lots of fun with the Gainclone, and since there seem fun to have with Class D as well, I thought that 50 bucks for this tiny amp (on Ebay) wasn't much.

It arrived today. Usually I use my 300B amp with Tannoy, but since I'm reworking it and as well building another tube amp, lately I just plugged an olf flea market Kenwood antique on a pair of .. flea market Klipsch KG4. Very pleasant. But back to the flea sized Indeed TA2021. Something is just .. "not right" All of a sudden, I'm in front of a 2 way set of speakers. Bass is articulated, but the treble seem uneven. Some shouting around 10khz I'd guess.

Is this amp supposed to mellow a bit with time?

Hi, im looking for 1 x ada4610-2arz-r7 to complete my Autoranger however it seems to be out of stock for the best part of a year! Does anyone have one they can part with?

Thanks

WTB (2) 4.7uF Jantzen Audio Superior Z-Cap or Audyn Cap PLUS 4.7uF

Looking to buy two (2) 4.7uF Jantzen Audio Superior Z-Cap's Or (2) Audyn Cap PLUS 4.7uF for a crossover mod I'm currently doing. Please send info and price with a PM directly

Also Jantzen 15.00 Ohm-10 Watt Superes Resistor, need (4) of them.

Located: US, CA

Thanks

Hi guys.
I have a CAD M179 condenser mic and I cannot figure out how to get the damn capsule out of the chassis. I guess it is glued in there.
Any ideas?

Thanks in advance.

Hi

For Sale: 1x Sound Master TA-377A Full Complementary symmetry FET stereo preamplifier kit, utilizing matched pair transistors on RIAA and line amp stages. Has transistor-based regulation on board. No power transformer.

Included: Main PCB with all components stuffed by factory, full instructions, two excellent Alps Black Beauty 100K pots (one for volume, one for balance), selector switch and wiring.

The Kit includes everything you will need to make a high quality pre amp, except a 2x 30v Transformer.

Price £35 plus postage.

Payment by paypal please.

I am struggling to attach photos for some reason (I have managed it before), but I will try and add some, otherwise PM me and I can send some direct.

Hi Everyone.

I have found this forum while looking for suitable speakers for my TV. I have been using an old Altec Lansing CS21 system and it sounded really good. Unfortunatly it as died, and the tv sound is pretty horrible in comparison. I used it for concerts on youtube ,spotify and netflix.
I do have some space restrictions,and while looking for speakers I came across the Fostex DYI kits. Not only they would fit in dimentions ,as i could finnish them to match the rest of the house (WAF is an issue..).
That being said,i have no way to demo them before buying ,and i am a bit afraid that they will sound worst than the Altec Lansing system .
I was thinking in one of this kits:

Fullrange loudspeaker kit Fostex FF85WK, with cabinet kit plywood 18 mm thick

Fullrange loudspeaker kit Fostex FF105WK, with cabinet kit plywood 18 mm thick

Do you guys think one of theese would suit my needs?

In my computer I use a single Ikea Eneby20 speaker and i am totally ok with the sound ,so i'm not super picky.

Thanks in advance for your atention,and congrats on a very nice forum.Really made me wanna get into this hobby!

Anyone interested in two pairs of these drivers? I have a pair of the ET-5 and a pair of the ET-5A monopole version of the Linaeum tweeter.

I picked them up a few months ago intending to use them for a DIY speaker project. I've never gotten around to that project and probably never will, so I figured someone else might be interested in these tweeters.

Hello Guys,

I have an odd one, 6080 OTL amplifier, I plugged in a new preamp and it blew all of the tubes (they exploded) on both channels.

So, changed the coupling caps, same thing, tested the cathode resistor, perfect on the money.

Checked all caps for leakage on the LCR, not an issue could be found.

Checked the loading resistors on the speakers, checked out...

B+ is as it should b, -75 rail is on the money bias, I just do not know.

I have NO schematic nor values, but I have the spec sheets for the tubes (EEC82 Driver 6080 Output), I know that too much current is passing to the K1 K2 but I cannot work out how...

I say this as I dissected one of the tubes and the connection from the K to Pin has gone.

Also, I put in a 6080, turned it off then on then off then on and bang... same again.

Any help would be great, I am scratching my hair away.

Björn

When adjusting focus balance, looking at the diamond pattern, I've read many places here, that it should be both large and clear.
So, is that done on the same trimmer?

And is focus balance the same is E-F balance? If not, how does one adjust E-F balance on a teac vrds-10?

Kind regards,
Jacques

Hi!

I got a little Sansui TU-555 tuner. When I first got it reception was very weak and no stereo. A lot of caps were bad so I started by changing them, touching up the soldering and replacing the famous 2sc458 transistors. The result was slightly better reception. I than cleaned the local/dist switch on the back and now reception is great only it doesn't decode stereo : I checked and double checked the orientation of the caps I changed, tested the 4 transistors on the multiplex circuit that are fine, changed the trimmer resistor, cleaned the remaining switches but there's no improvement. When I turn the trimmer resistor clockwise all the way I have a faint glow from the stereo bulb when tuning to stereo stations but when I listen to it it's clearly still mono...

I get that this site is dominated by engineer types who seek perfection but sometimes the goal is improvement as opposed to perfection. What with a limited budget and available components.

My first argument was that, for the money, commercial manufacturers can build better cabinets than diy'rs.. So I purchased a JVC home theatre 19 litre sub for $7. My initial plan was to replace the 6.5-inch driver with an 8-inch driver obtained from a Tannoy sub with a dead plate amp (cost $15). However, I sold the spike feet on the Tannoy for $10 and the driver for $25 because the location of the port on the JVC would make fitting an 8-inch driver tricky.

The 150w JVC sub sounds nice, smooth and sweet but the problem was always going to be: SPL 77db / 30Hz / 6 ohms. After a debate with Chris661 and Weltersys they intimated that substantial increases in SPL could be obtained by an increase in diaphragm area.

Using only the components I have lying around this is the upgrade:

Don't you think this is a fun waste of $7?

Is Burr Brown OPA627AP the best way to go? are there better OPAMPs for the 405 to use?

Sorry for asking, but I have no formal math on this kind of circuit and it escapes me.

What's the input impedance of this tone network with the short vs without it?

Meter says 5k while shorted...

Beyond that, I could learn but I'd need "handholding" in this case.

Thanks as always 🙂

BTW I think I like the curves better with replacing all the 3's with 2's in the cap value.
Koda

Hi,

I have a 15" subwoofer I built, using 25mm plywood (you can see the cabinet with the green grille in the image of my vintage system!) and I use this subwoofer amp BSBPV500

(they used to manufacture for REL in the early days I believe and they seem to know what they are doing ...a lot more than me!)

My brother with 3 Sonus Faber subwoofers like the sound of mine and tried the BK amp direct into the sonus subs bypassing the SF amp, and he and ended up with 3 replacing the integral amp with the BK. He uses digital signal processing to align his which I tried and did not get on with.

I made a 12" version of my 15" sub with the same brand of driver for a friend who borrowed my 15 and loved it, but his room could not put up with the cabinet size..

Anyway the preamble set's the scene for the question. When I make my subs I use a CNC shop on a full sheet of 25mm ply, and with the 12" I was able to get two cabinets out........so I have the chance to try a 2nd sub.

BUT I would rather not also invest in a 2nd amplifier if possible (which would give me independent phase control of each sub with the integral control on the amp). So is there any clever way to create a phase adjustment for the 2nd sub with a passive controller?

Thanks,

Hi, I’m trying to repair a Vitus RI-100 integrated amplifier. This amplifier has socketed input modules, one per channel, please see picture. One channel has high DC on the output. It starts low, when initially powered on and then quickly rises to over 1V DC as it warms up. If I swap these modules between channels, DC problem also swaps. So I have it narrowed down to the module.

The amplifier works and produces sound, but I’m assuming that one or more of the transistor is partially leaking DC. And over 1V DC is extremely high.

The little SMD transistors are labeled RS and TS. I cannot seem to find what these SMD codes correspond to as far as actual transistor part numbers.

Any help would be greatly appreciated.

1J(1Ж).., 2J(2Ж).., 4J(4Ж).., 6J (6Ж).., 10J(10Ж).., 12J(12Ж).. tubes for sale

Sale:
1J17B for $1
1J18B for $1
1J24B for $1.5
1J29B for $1
1J37B for $1.5
2J27L for $1
2J27P for $2
4J1L for $1
6J1B-V for $0.5
6J1P for $1
6J2B for $1
6J2P for $0.5
6J3 for $1
6J3P for $0.5
6J4 for $0.5
6J4P for
6J5B-V for $0.5
6J5P for $1
6J7 for $2
6J8 for $1
6J9P for $0.5
6J9P-E for $1
6J10B-V for $0.5
6J10P for $0.5
6J11P-E for $1
6J20P for $1.5
6J21P for $2
6J22P for $1.5
6J32P for $4
6J43P-E for $1
6J49P-D for $2.5
6J49P-DR for $4
6J49P-DRU for $4.5
6J52P for $2
10J1L for $1.5
12J1L for $1.5

Hi Guys

Does anyone know the reference of the integrated of that driver card?

Im in the work of recapping a old vintage class a/b amplifier i own.
A Sonotron pa200 .
Sonotron as a brand existed only for a few years in the seventies until the production got moved and they changed the name to adyton. A name that are more known and are still known today .

while im waiting for parts i thought, why not make a schematic for it and make some posts along the way?
So said and done
My computer is not the latest model so not many drawing programs would not work, so i found digi-key's online schematic drawing program. So im learning to use it along the way too.
This project are mostly for fun, and maybe someone here have seen a similiar schematic. And maybe help me along the way . Who knows. Maybe modify it to sound better or do other things with it.

Im gonna post the llttle info i have collected over the years and updates of the progress 🙂

Hello FEMM and COMSOL experts out there.


Anyone here willing and able to do a basic sim about the properties/BL behaviour of the Purify 6.5 midwoofer's alternating 3/4 layer voicecoil?


According to Lars Risbo, designer of the Purify 6.5 Woofer:

the winding has 4 layers but with typically 2 to 4 gaps where the coil is effectively only 3 layers. These gaps flatten the Bl(x) by reducing Bl around the rest position. This trades some sensitivity for much better linearity (the reduced mass due to the gaps compensate to some degree). the positions and widths of the gaps are found using computer optimisation of a finite element model. I hope that explains it better.

I have MANY drivers and amplifiers. Time to upgrade and re-arrange. On the low end; I have the SB23MFCL45-4 single in a closed box just under 1 ft^3 powered by an older Hypex DS 2.0. I will eventually add a second one but will have to wire them in series for 8 Ohms. The Hypex does great with 4 Ohms but no way could it do 2 Ohms. This won't increase my overall sensitivity I realize but I will still have twice the surface area and I'm guessing I would increase the SPL's because the Amp will have an easier load. I never have to turn the main "gain" control up past the half-way point. With all bass EQ settings, in room response goes all the way down to 14 Hz! Remarkable for a single 9 inch sub. in a small, closed box! The Hypex has a non-defeatable 12 Hz high-pass (I think 4th order?). Moving on up from there...

Have you ever make tube socket adapter? If you have please share your ideas. Here I want to share the way I made it. The pins are pulled from wafer connector and square pin, one side is grounded round to ~1mm diameter (on press drill or hand drill). The ceramic tube socket has a small recess on top so a M3 nut can be fitted level to the socket. M3 screw hold the 2 sockets together tight spaced so the pins are 2mm apart. The square end of the pin tinned and then push into one of the socket receptor, and soldered. I wired it up for pentode strapped triode of a pentode triode tube, such as 6f12p so the tube pins are compatible with 12ax7, but G2 is wire directly to plate in adaptor so that pin 9 will be freed. It's a great way for comparing tube sonic without rebuilt another circuit.

12ax7 6f12p
1 3, 8
2 6
3 7
4 4
5 5
6 9
7 1
8 2
9 -

Hi.
Can someone help me with this IC.
Whst kind of IC is it?
IT is located at the input side om a subwoofer amplifier.

Think it says ST ZBGA439 but not sure.

Thanks for any help.

My latest and one of my favorite for looks unfortunately not very good for a mic.I left the mahogany veneer on the wood which looks good against the gold glass horn.Headphone element is used for the mic element.

Imgur: The magic of the Internet

I've got a bad fan in my 5800 and have ordered a new pair from Adcom parts, but they seem to have been delayed. So, need to find a temporary substitute locally. There's no identifying markings on the fans, so I have no idea what the CFM or rotational speed is. I have determined that the good fan will turn on at a voltage of 3.95. Has anyone else had to substitute a fan in this amp and what advice might you have? CompUSA locally has a fan of the right size, that will turn on at 4.6 VDC, so maybe that will suffice.

Hi all,getting ready to start another project a 2270, I am in the process of putting my BOM together and take a look at these main cap's the unit calls for 9000uf 55v these are not even close, what do you guys suggest to use??? This should be a challenging project!!!!

I'm referring to the heatsinks on Q3 and Q4 on the BA-3 front-end board: https://files.diyaudio.com/archive/gallery/data/500/IMG_04151.jpg

There are no mount points for a heatsink on the board. The heatsinks I selected don't sit flush on the board, and bend back and forth as I connect test probes and such. Can someone suggest a heatsink that will mount flush with the board, or otherwise make secure contact, so that it doesn't act as a hinge on the transistor legs?

Ventus is a mostly discrete opamp. 🙂

This is a circuit designed for some DIY fun. It is based on the Diamante circuit I published a while back.

The front end is a folded cascode design and runs into a LME49600 buffer. The buffer is in the feedback loop.

A schematic is worth a thousand words.

It sounds excellent. It can drive low impedance headphones exceptionally well.

As shown it is a BAL/SE converter and take balanced input from DACs such as Buffalo or Opus.

I would suggest when using it in this way (Balanced to SE) you use a relay to shunt output to GND on turn off to prevent any turn off thump. The thump buster works well in this role.

The Ventus can also easily be setup as a classic non-inverting amplifier with single ended input. It also can be setup as an in inverting amplifier with single ended input.

Each module is a mono channel so It takes two for stereo, and they stack easily.

There is a pot to null output offset.

We have boards tested and parts are en route so these will be available very soon.

The board is tested and proven, and I love it. I have been listening to it for a week now.

Take a look.

Cheers!
Russ

$450 posting for a friend. Local pickup in Oxnard Ca. PM if interested.

SALE PENDING: nice original Khozmo Passive preamplifier 3-inputs selector and Khozmo 48-step attenuator. 25K value, version with Caddock Mk132 + Vishay/Dale RN55. Very nice RCA connector.

Added bitumen vibration absorption pads inside the chassis.

See WWW.KHOZMO.COM - High Quality Passive Preamplifiers for the exact same model.

Still sell for 300$ from Khozmo, asking 200U$ + shipping + Paypal fee

Thanks
SB

Hello greetings
trying to make this kit enclosed is the schematic as i have
little knowledge in electronics is this crossover supposed
to work with +/- 6 volt regulated dc rails
warm regards
Andrew😉😉

I see one on Ebay UK but it's in poor condition for the price asked so the singles do appear on the market from time to time.

I have built a balance line stage preamp and would like to be able to connect a tape deck so that I can record from the output, as well as having an output connected to the power amp. Any ideas anyone?

I have built a tube headphone amp with following power supply.


I got transformer with only single heater supply and a pair of 6X4 so I designed a power supply using rectifier tube with shared heater supply.
The heater supply MUST be virtually grounded using 220R (in my case). But this would cause negative potential voltage between heater and cathode which is around -280V in my case. I know the negative potential voltage of 6X4 is rated 450V which my amp should be and it's being working without problem. But this make me worried cause my people said this might cause short between heater(GND) and cathode(HV) and blow all the tubes. It just a matter of time, they said. They suggest me to get another transformer for 6X4's heater which I am going to do. (6.3V 0.5A should work well🙄)
But outside this solution. Where should I put my fuse when I'm gonna prevent heater-cathode blowing? Or any other suggestion? (including 'don't do anything' one)

I’m investigating a strange issue with a proven design: I’ve multiple 866A diodes that in their bridge rectification duties begin to flicker. It’s not on and off flicker, it’s as if the gas is glowing on one side of the tube then the other maybe 4 times a second.

There is no fluctuations in voltage and the music sounds fine but I feel I must not continue listening if I’ve got a tube flickering.

I’ve rotated positions so I know it’s not the hardware, it’s maybe pressure within the tube? I don’t know. I’m asking for information 😀

I’ve got a dozen 866A so I’m rotating through them to find a fourth (I have three that are rock steady if low glow...) that is steady at this point. I’ve been breaking in the candidates with a four hour burn on the heaters on a board out in the garage. All the tubes were sold as NOS. I’m still wondering what’s going on...

Please assist if you’ve got a good guess.

Has anybody seen this before?

I have a pair of Fostex Fe126En drivers in boxes I made to the OEM spec. Sadly one of the drivers has failed and my children have damaged the other one. I wax looking for replacement drivers but saw that the Fe126En has been superseded by the 126NV. Is it a true drop-in replacement that would sound at least as good in a box designed for the 126En or just a newer model in that size category, requiring a different box? (I can still obtain NOS 126Ens so just wondering whether to stick with those or if there's any benefit putting the 126NVs in the existing boxes. I don't have the time to build a new pair of boxes at the moment...)

Greetings, All,

I’m obviously not electronically inclined, but I’ve recently discovered the pretty simple-to-assemble evaluation kits for Hypex NC400 and Purifi 1ET400A. I think I would like to build a couple. I’ve also seen quite a bit of activity on the need (advisability) of a custom buffer for these amps. And it looks like prominent member @tomchr (Neurochrome) has already built said buffer and is offering it for sale.

Reading through the discussions, for the life of me, I cannot figure out whether this buffer is necessary or optional and, as an end user, what benefits I can expect.

Can someone explain the necessity and/or user benefits of this buffer in simple English? Also, if highly advised, can it easily be added to the EVAL1 or GhentAudio or DiyClassD kits? Are there instructions somewhere?

Thanks

hi all,

Given the lack of availability from mouser and RS I was wondering if there was a decent substitute, ideally pinout compatible but not a problem if it isn't.

I have some 2n5551s and so e BF422 that seem promising.

It's for an input differential pair on a mosfet amplifier, if it makes any difference.

Sorry in advance if this is a stupid question.

In a tube rectified PSU that is CLCLC, I know the first cap size is limited by the rectifier, but does this cap need to be polar, non-polar, or does it matter? I was planning to use a 5uF cap I have on hand in that position, but it's non-polar and I can't wrap my head around what would go on in that case. Since one side is attached to ground, I think it would act like a polar cap. Unfortunately I don't have the spice/modeling skills to look at it (and I don't think PSUD has non-polar cap options).

BTW, I kinda need a cap input for voltage, but want to keep the rest LCLC. Any thoughts or explanations would be appreciated. Thank you!

My Nuforce DDA100 integrated amplifier started to have some issues recently and I traced the problem to the (Skynet SNP-G series) 28V 120W SMPS which is buzzing/hissing quite loudly and has a faint burning smell. The amp works perfectly fine running off my bench power supply so I’d like to replace the power supply. Im looking at these two power supplies, the Meanwell EPS-120-27 no PFC or EPP150-27 with PFC. Any opinions or other options? Thanks
https://www.mouser.com/ProductDetail/MEAN-WELL/EPS-120-27?qs=Kh9WxvXxjWm29iR9914aXg==

https://www.mouser.com/ProductDetail/MEAN-WELL/EPP-150-27?qs=Uzd/wh%2BZzhAREbslZUMOsQ==

Hey all!
I've just removed the old selenium rectifier in my PAS 3. I've mounted a terminal strip with 2 new 4700uF capacitors and 2 1N007 diodes. I just want to check with the experts here if the positioning of the diodes are correct? The wiring is exactly like it was in stock form as well as the polarity of the caps. As I understand it I should remove the tubes from the line stage and phono board when firing it up and checking the voltages?

every time I am ordering caps for power supplies, I see audio grade caps that, at least on mouser, it is only Nichicon and maybe sometimes kemet. while general purpose is available from many manufacturers. so far I have always ordered audio grade, but is it really necessary?

Hello !

I've been out of this a long long time but have been listening to and enjoying my home built stuff with a sense of pride...that it all still works !
That said, I've been getting itchy feet recently but too afraid of disturbing my successful Arcam Alpha CD with a shed load of mods I decided to do a bit of reading to see what else was out there that I could cheaply muck around with.

Not sure what you lot think but..I like the Lampizator site and the narrative sometimes makes me laugh out loud and Fikus always attempts to tell the truth...as he sees it anyway..lol

Anyway he seems to rate any TDA1549 based CD Player as pretty much ' up there ' with some expensive ones as you probably know already and it really fired me up once I'd taken a look at the simplicity of them.

So I got hooked on the teachings of TDA1549 in the Phillips and Marantz machines and bought two CD48 players for £50 ( for both )

I downloaded everything, read the lot and finally stripped the horrible thing down to a single green main board.
The 1549 DAC chip is the V out type ( as opposed to current out ) which means we can use the clean signal of the output legs ( no 4 and 7 ) of the chip straight to the rca's via a couple of coupling caps.
OK....so this is nothing new and you clever ones knew this already maybe but today I actually got round to doing it - including removing the op amp. I really enjoyed removing the op amp for a change instead of ' rolling ' them. God knows how I've wasted money on that hobby...🙄

I have listened to the player for quite a while and was surprised and impressed by the mids and treble initially but eventually found it a little forward and fatiguing compared to my very liquid and analogue sounding Alpha.

I'm pleased to say that this VERY simple mod ( 15 minutes - ish ) has jettisoned this player forward massively and so I've decided to apply several other changes to see how far I can take it.
I'll also be posting pics soon and some explanations of what I'm doing or trying to do if anyone is interested.

After all - this is how my Arcam Alpha came to be from reading the ' Arcam Alpha Mods ' thread from years back.

Please note : I'm no engineer, mathematician or clever sh... but have sufficient skills to implement additional improvements.

So, currently the CD48 has lost almost all of it's hf glare and a lot of the hardness in sound which I'm putting down to losing completely it's entire output stage of some 40 odd parts plus the crap dual op amp....
No loss in output either....same volume settings.
It sounds much better and is already matching my other machine in some if not many areas - no real analogue liquidity yet but I reckon I'll find it soon.

Next up is the diodes, all the caps, independent power to the DAC chip, improving the main but cheap 05 regulator which once powered the whole machine, eventually the clock and anything else I can think of...or you can think of if you have any advice.

If you've done one already please give me a steer....I reckon I'm on to something - and it's going to be cheap too !

Rgds

Andrew

Ultra-low jitter oscillators 22.5792, 24.5760, 33.8688, 36.8640, 45.1584, 49.1520 MHz

Ultra-low jitter clock generators ГК154-П-Т, made in Russia, http://bmgplus.ru/images/pdf/pdf154T.pdf , DIL-14 packaging, 5V supply, tristate mode. The really best oscillators for audio.

Pin 1 Open or '1' level - Enabled, '0' level - high impedance, Pin 7 - ground, Pin 8 - output, Pin 14 - Pover supply.

512Fs - 22.5792 MHz, 24.5760 MHz, 768Fs - 33.8688 MHz, 36.8640 MHz, 1024Fs - 45.1584 MHz, 49.1520 MHz

52$ one oscillator

33.8688 MHz temporarily unavailable. But pllease let me know if you need this item
Alsou is possible to produse ГК155-П-Т - 3,3V supply version, but it takes very long time.

Also
Digital filter
AD1896AYRSZ - 14$

DACs
AD1955ARSZ - 10$
AD1852JRSZ - 9$

Op Amps
OP42FJ TO-99 metal can - 17$
OP42GPZ DIP8 - 9,5$
LT1122ACN8 DIP8 - 10$
AD823AARZ SOIC8 - 6$
AD811ANZ DIP8 - 9$
AD844ANZ DIP8 - 10$
AD845KNZ DIP8 - 16$
AD815ARBZ - 10$
OP484ESZ SOIC14 QUARD OP AMP - 16$
LT1217CN8 DIP8 - 6,5$


Voltage References
AD586MNZ DIP8 - 9$.
AD586BRZ SOIC8 - 9$
ADR4550ARZ - SOIC8 - 5$

EPM7128STC100-10 CPLD - 12$ Embedded - CPLDs (Complex Programmable Logic Devices) | Integrated Circuits (ICs) | DigiKey

Shipping from Russia 10$ - 12$
Paypal, VISA, other variants can be negotiated
11 oktober 2020 edited, list is aktual

Project removed from thread.

Has anyone (recently) ordered BUF634 ICs from China (e. g. Aliexpress, Ebay)? Is there any chance those chips for $2.5-$5 are not fake, while the official price is around $20 per piece in bulk?

Hi everyone .Some while ago I had a pair of alpair 10M in a vented pair of 15 liters and because I've loved it so much I built another pair of speakers with 2 pcs each (30 Liters) . Even better , stronger powerful , just perfect . Almost perfect , because I thought my self " what if I make a new pair with 4 drivers for each speaker ? " Honestly I was inspired from Eikona but I believe it's risky to just copy that plan because it might not match ; so I guess , classic vented will be enough .Can someone help me with winISD ? I'm not lazy but I'm just not very good with it .I'm open to suggestions . Thank you

Hello

I remember the very good sound of the first Denon PMA-700 amp from the 80's, in those time I never seen the schematic and can't find the first version schematic of that amp.

But I have the PMA-700AE schematic, what is the differences between the PMA-700 amp from the 80's schematic and the recent PMA-700AE schematic ?

Thank

Bye

Gaetan

Hello, I have been a big time lurker here for a few years, but finally thought I'd ask a question for something that's been bugging me for a long time. I understand the general difference between an acoustic and electrical slope and their phase ramifications. Furthermore, I found at least one post related to this but it didn't specifically answer my question. My question pertains more to the way talk about crossover slopes in forum posts, articles online, etc. I'll use an example...
In D'Appolito's article about the Thor system (THOR: A D’Appolito Transmission Line | audioXpress) he talks about the requisite crossover slopes, e.g. on page two he says, "For the THOR TL the goal was to design a fourth-order acoustic crossover response at a crossover frequency of 2500Hz." Is he talking here about an electrical fourth order crossover, or a lower order electrical crossover that achieves a fourth order roll off when summed with the natural roll off of the driver?

BTW, I've read e.g. LDC and a couple other books, but they don't clarify this for me. I now realize that I could have learned how to read the crossover diagrams in the article and answer this for myself... thank you for indulging a bit of my laziness.
P.S. Thank you to the community in general for so selflessly sharing. I'll pay it forward one day when I've achieved the requisite level of audio DIY fu.

Hi. I have a problem with a Proel Wave 12A speaker which the high signal does not reach the amplifier module.
Does anyone have the PRE-AMP scheme of this speaker or do they know the reason for the malfunction?

Thanks.

FS A pair og the new midrange Purifi driver

it is 8 ohm and only used for test

this model PTT6.5M08-NFA-01 - PURIFI

it is only for midrange and crossover from 100 hz and up

price pair 730euro

Best Bjarne

I just built two of Jbells SS15 using 3015LFs and am blown away. I first powered them with a Yamaha PX3 bridged at 4ohm mono and now a Behringer NX3000D limited. These are a little large (physical size, mostly height) for some of my small gigs

I now want to build a small compact single sub to supplement my smaller systems.

I am considering the Cubo 12 because I like the size of it. I could go for a premium woofer (Amp options above) to maximize the power I already have. Ideally 4 ohm.

Thoughts?

I would like to switch filters on and off in a 1701 via the GPIO pins, however I cannot see how this is done. Can anyone help?

Hello all,

I'd like to build a 5.1 amplifier for my office to take analog signal from my sound blaster card. ATM I have a old logitech Z5500 kit and I have already replaced some speakers by Minx Mini one. I don't need an high fidelity amp I just expect something a bit better than the logitech I have now.

I am a DIY guy but one week ago, I was knowing nothing about audio. And I still don't know very much 🙂

My current project consist of various modules assembly. But I can weld electronic if required.

Here is my first try :



My questions :

- First of all, will it work fine ? 🙂

- I plan to use an active subwoofer, can I output to it an already amplified signal or should I send the raw analog signal ?

- It seem like in 5.1 schema, subwoofer use the center signal but what happen if I listen to stereo music then ? No subwoofer I guest ?

- The TPA3116 module have a gain potentiometer on each, is there a way to add a master volume above them all ? The idea would be to be able to adjust each individually (like decreasing the center) but have a master volume to simple lower the general volume.

Thank a lot if some peoples can take some of their time to give me advises.

I have have a active filter for my TAD 2402 clones today but will now make a passive crossover filter and has found the diagram "TSM-2" with information regards to what I need.

On internet I did find some different versions regards to components sizes for TSM-2, but I got the question about RDC for the Inductor's ?

Is there anybody that could help me with that information ?