Software Defined Radio, In Audio

Yes I did a search.
I got a cryptic message from a cryptic friend You need to get into SDR.

1. I want to measure EMI / EFI esp pertaining to transformers. Some of my junk yard transformers sound better than others. This is mostly down to the enclosure. They wrap the complete transformer in copper. How thick should the copper sheet be to work. Can an SDR tell me anything about the noise a transformer makes ?. And how well my insulation has helped. Copper sheets are priced on thickness so if a .25mm thick sheet works I don't need to bother about buying .5 or 1mm.

2. As always on a tight budget. Given what Im trying to achieve. What would be cheapest / lowest level SDR setup I could get away with. Ive heard stuff like 10$ USB dongles.

3. In what other way can SDR help us build and tune better Audio gear.
Christmas is when kids and friends return to india so thinking of getting a basic sdr setup down. But I have to justify its use as a tool.

Pioneer GM-D9704 in protection mode

Hi,

First of all I have to say I am a reaaaal beginner at fixing electronics and especially amplifiers.

I recently got myself a Pioneer amplifier which is locked in protection mode.
I checked all of the big Mosfets and they seemed good.
I found 1 thing that was weird for me. I found 2 diodes which seemed to be shorted -MBRF20200CT and MBRF20200CTR. I pulled them off the board, but when tested off board they were fine. So a question popped my mind. Are these point supposed to be shorted together?
1700650231324.jpg


I found out these points end up in the transormer:
1700650231333.jpg


Are all of these supposed to be shorted together?
What else should I look for?

The amp shows blue light like a millisecond and goes to protect right away.

Looking for Music that covers all Freq

Ok first of I have spent days searching for this info.
Not finding anything Im asking the question.
Im looking for music that covers all freq from 30Hz to 20Khz.
Or even if its split into parts like Music for Bass testing. Music for Mids and music for highs.
The best bet would be to have a track that covers everything from Freq range to stage separation.
I like to listen to music with RTA s/w running on the laptop or phone. With peak hold. And at the end of the song with a glance I can see what freq hit what DB. And how swapping out a driver in the equation impacts the RTA results.
So a CD does a better job from 4K to 10K. But falls flat on its face after that. A silk dome tweeter does a better job from 8K to 20K just examples of what Im trying to figure out.
Or just what is your fav music you use when testing and why.

Need help finding two parts H15BLK power conditioner

Hi Everyone

Need help find alternative for below two parts.

I am using APCH15BK power conditioner for voltage regulation and surge protection. Sadly, some components burned out. Relay got burned over time due to external heat from Varistors, yesterday when I plugged computer PSU into the socket, Varistors started burning and turned to ashes. I believe their function is to protect from surges.

1. Relay
Part number : 875B-1AH-F-C 12V DC (17A 250VAC, 20A 125VAC)
Images : Login to view embedded media Datasheet : https://www.mouser.com/datasheet/2/378/875b-347335.pdf

2. Varistors
GNR 20D241K
Close but not thermally protected : https://www.mouser.com/ProductDetail/652-MOV-20D241K
Thermally protected but some difference in energy rating : https://www.mouser.com/ProductDetail/576-TMOV20RP150M
I found similar on mouser, but I am looking for thermally fused ones so they don't catch on fire or burn down my house.

Thank you

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How Should I Use Simple DSP Amp Modeler Like Flamma FS06

Hi Folks,

while I am trying to get to the bottom of a slight malfunction that my Flamma FS06 amp modeler pedal is displaying (in another thread), I began to wonder if in my noob naivete I even use such a pedal correctly? I know that whatever sounds good is correct, and Flamma still gives me the best tone so far, I feel like I am not using its full potential judging by some glowing reviews I saw.

It is supposed to model a few popular amp models, both clean and dirtly channels for each, and it has a built-in cab sim. So I assumed I just plug the guitar into its input, plug its output into the mixer, and that's it. And it works reasonably ok but the sound still sounds kinda thin no matter what I do. Even with distorted channels, and some of these models are really distorted, I can get a lot of noise but nothing quite like punchy power chords or soaring gilmoury tone.

It may very well be my other components, which are nothing fancy.

But I was thinking that, if this is really an amp simulator, shouldn't I have something like a tube screamer before it? What is a standard way to use a pedal like this?

Thanks!

Taramps HD3000 IRS2092 version - low power

Hi everyone, I'm repairing a taramps hd3000 compact, the version with irs2092 as driver.
I will have repaired about twenty of them during my career and if memory serves me correctly, I always had the feeling that these sounded really soft, while the old version (the one with IR2010S as driver) sounded very loud already with a low input signal, so much so that you have to be careful with the gain potentiometer.
I've checked everything, absolutely everything, but there's nothing wrong.
The amplifier works perfectly, it draws the right current, it has no background noise, the voltages are right, it just doesn't sound much.
Has anyone noticed anything similar on this model?

For Sale Nippon chemicon kmh 80v 1500uf

And here are 45 now capacitors, all stored indoors.
80v 1500uf.
35mm diameter height 20mm pitch 10mm
Take all 45 euro
I dont have any means of checking the properly, I include a photo with fluke capacitor test, I have ordered a hantek 1833c but it is still in shipment somewhere.
I tried the bigger capacitors but it gave up, unable to do reading. It's a poor function in the fluke

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LCD display monitor for tube amp

Hey,
I would like to monitor and display real time data such as bias, filament voltage, hours of operation and other parameters from my tube amp. I have seen a picture of this done on a tube amp but there is real useful information other than pics. Also found some info on data logger but it doesn't seem to be applicable. I am not really sure where to look. Has anyone done this or have any pointers on how to do it?
thanks!

Technics SB-CS65 speakers to repair

Hello everyone,

I have a pair of 30 year old technics SB-CS65 speakers, and only the subwoofers are working properly. The mid and high range are almost gone.

I tried both the 4 inch mid range driver and the 3 inch tweeter with a direct connection to the amp, at a low volume, and the sound is very low, similar to when they were connected to the crossover.

The speakers are rated 60w / 8 ohm.

The woofer shows 7ohm, the mid range shows 4 ohm and I have no idea about the tweeter impedance.

I need help deciding on what kind of not-too-expensive 4 ohm 4 inch mid range I should get, and also about 3 inch the tweeter impedance and power rating, as they seem to be connected in paralell to the crossover high frequency side.

Thank you for all the advice you might want to give.

Daniel

Restoration / fresh up Kenwood KD-5070

Hello together,
I`ve had the opportunity to a get my hands on an may be 40 years old KD 5070.
It runs. Plate is spinning
Automatic mode dosn`t work at first time, some parts inside was stiff because they didnt move the last 10-20 Years.
Moving manually helped i little bit, now all is working.
Next i will test the output, to ensure the cartridge is working.

Have someone the same turntable and made a fresh up?
Which points are important? what is useful to do?
Would you change some parts if everything is working? Capacitors may be?

Do someone have the service manual drawings / Schematics / assembly instructions?
I have only found the owners manual, but this will not help me that much.

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For Sale DC power module gainclone LM3886 or LM1875

After abandoning a project, I have two power supply boards left, equipped as follows:

The board kit include:
  • one complete power DC board equipped with good quality 24pc - 2200uF / 35Vdc capacitors (totally 52800uF on both rails)
  • optional is possible to put on board 1000uF / 63 Vdc capacitors

Note: NO power transformer, NO soft start function

Price for one complete board kit is 50 Euro+15 Euro shipping to EU. I am sending to EU only.

For more details, please send me PM.

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Dome tweeter: Auminium vs Magnesium... marketing

Hello,

We often talk here and elswhere about the properties of metal domes, and for the classic round shape, most of the time the discussion comes about the break up position and the internal damping of the said material (Be, Aluminum, Magnesium, ceramic, allows of those, etc)

I would like to focus on the often seen aluminium and magnesium allows as few are making 100% Magnesium dome tweeters (Fostex, Audax, ?)

So Magnesium is circa 1/3 harder at iso weigth than aluminum, i.e. 1/3 ligther at iso hardness.

Most of the time, I bet diferences are more due to the spl magnitude of those tweeters, the break up area relative to the materials we listen to, especially if non oversampling source and materials (16/44 with NOS digital source).

What about the internal damping many claim to be the force of the best materials like the Beyrilium and for the topic of the discussion : the magnesium ?

Aluminum is said to have good internal damping if I am not wrong at iso density vs some other metals used in tweeters like the Titanium or ceramic for instance, and our talked magnesium. I.e. aluminium is "softer" at iso mass which is not so bad but the early break-up - often circa 25k hz- !

Looking at the datasheets of some dome tweeters having pure magnesium or allows mixed with alumen, I am wondering "WTF" about those mixes ?! Indeed, most of the time the Mms is not ligther when Magnesium is entering in the comp of the tweeter domes : we often have the same weigth in the datasheets : 0.3 g to 0.4 g. the 0.4 g being sometimes the one with said ligth allow with the said Mg (or Be...).

Is that pure marketing ? Or does the Magnesium adds "something" ? More hardness at iso weigth (which is maining also maybe more early break-ups ?)
Also as Magnesium is harder, doees it mean less damping, i.e. more harsh sound ? All these things are not so clear to me !

I have the temptation to say that the most importat thing is the spl magnitude shape arriving at listening position. But voilà, micro details or details at low spl level are involved in the discussions soon ?! And because of that I am tempted to focus on hard dome tweeter VS soft domes, as the decay of notes in acoustic intruments is importat for me! Ah, so I imagine we talk about both of waterfall decay and ... what ? hard domes ... hardness = micro details? Is it clear for you ????

Not saying in the passive crossovers I experienced tons of way to make sound a hard dome different with the caps receips that color the sound more or less but anyway adds (it is a default, of course) to the sound ! I can make the Stan Getz saxo wood anch sounding like I want just playing with caps, for instance !

Is there some better voodoo you heard with Magnesium vs Aluminum ? Should I mortgage for Be by snobism or what ? Forget it and buy a good informativ soft dome tweeter à l like the 3004/66000 ?

Throw it all and focus on the magnitude off axis shape in the listening room by hundred mic measurements and sims with a tweeter you already have on hands? Or definitly focus first on the dome material choice then make your life after on the dev side of the filter ?

Mosfet needed for smart 8k

Hi guys. Need this power supply mosfet however I can't find any online. Been discontinued by the looks.
For a taramps smart 8k bass.

Problem is I only need 1 (or 6 to replace the entire bank on the transformer. (24 total)

I'd obviously like to just replace 6 in the bank rather than all 24 to an equivalent
20231121_134452.jpg


I don't trust aliexpress. Or ebay

Anyone have a place to get them or have 6 I can buy off u.

Will need to be shipped to Australia

Thanks 🤞

Small Portable 3 Way Multi Entry Horn

I have been designing a very small multi entry horn to replace a 10" reflex portable speaker I built a few years ago.

My main goals have been to get the same low end extension but in a smaller size and not necessarily as loud using drivers I mostly already own.

The box is currently 30.4cm x 26.7cm x 34.1cm but I might make it a bit bigger to get a bit lower

The drivers I am using are:

Faital Pro 6fe100
Faital Pro 3fe25
Faital Pro HF100

I used ATH for the initial horn flare

To power it I am going to use The Sure Electronics Jab5 amplifier which has 4 channels so 2 for the bass drivers, 1 for the mid drivers and 1 for the compression driver with a built in DSP

1681203147844.png


1681203359430.png
Portable Unity.png


Still need to add bolt holes and something to attach it to the box but it will print in two pieces. Each piece is currently a 20 hour print at 0.2 layer height.

I am gonna look at getting it finished and printed this week if I decide I am happy with the sims haha

1681203252981.png


1681203340487.png

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This is the speaker I am looking at replacing

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eMail bounce @happyhappy

@happyhappy

Bryan,

My last email to you keeps bouncing… the one about multiway miniOnken.

Side question, have you ever seen a two way system in an Onken enclosure?

None at all. We have done a few. I have a set i need to finish assembling downstairs.

CSS-2-way.jpg


IMG_4006.jpeg


dave

Note: miniOnkens are not “officially” Onkens, they only borrow the slot vents down the sides.

RCF 21" woofer LF21N451

Hey guys

Years ago when I was really into home theater I bought this RCF 21" woofer and had it in a massive ported box under a workbench in my parents basement. I moved into an apartment about 5 years ago and this driver has been sitting in storage in an ocean container behind my shop ever since.

I just bought a 2500 square foot house where I can now do whatever I want so it's time to bring all the old gear out of storage. I was planning to pair this in some way with my Martin Logan Aerius I speakers. I'm not moved in until December 17th so I don't have room dimensions and I'm not even sure where I'll be putting everything.

I was wondering if anyone could shed some light on how I could make the most of this driver? I would power it with Behringer EPX2800 and use my Dayton 4X8 DSP to set the crossovers. Or should I just scrap the idea entirely and go another route? I'm pretty open to any and all ideas.

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(4) Eminence NSW6021's for sale, new/used

Hello everyone! I am in Houston TX and I have 4 perfect condition NSW6021 drivers for sale, two are unused (I did break them in through free-air testing to make sure they operated correctly though), and the other two are in cabinets (one sealed 4cu ft, one VERY big ported box, approx 18 cu ft I believe, tuned to 19hz or 27hz depending on if you block one port) and have never been powered with more than an NX6000. The NX6000 has a true RMS wattage of 2,000 and a true peak wattage of 2,500. So considering the fact that I wasn't riding the limiter of the amp, that means the two drivers that had power sent to them only ever saw around 1000 RMS and 2000 peak, so I operated well below their ratings of 2500 RMS and 5000 Peak respectively. I'll be selling the unused/new drivers first.

The best way to contact me is on discord but I will also respond here, it will just be delayed. I would prefer local pickup but I can PROBABLY work out a shipping deal, I have the original heavy-duty shipping boxes so I'm not afraid to ship them, and if you happen to order all 4, I might just drive them straight to you myself if you're not too far. If we're doing digital payment methods, I accept Zelle, otherwise cash is king.


My discord username is: classicality and this is BY FAR the best way to contact me



Current pricing is $950 AFTER TAX (over $300 discount from new), and there is no pricing distinction between any of the drivers, they're all perfect, but I will ship out the unused/new ones first. I'll add some pictures later on Wednesday, but there's really not much to see, they're perfect.

Also if you're local I can build cabinets too (for a price) in case you want to use the drivers immediately, I'm not a super high tier professional like a cabinet shop, but I'm also not an idiot. My cab's function well.



If this is in the wrong place on the forum please tell me where (or if) I can post this, thank you!

GB: Round #10; Fo-Felix AC Filter

Back by popular demand! Please note that it can take a few months to get everything. Supply chain issues have made it take longer. Some have wanted different parts for that reason but the popular opinion still remains on preferring the very nice quality ones originally included.

The Big #10!

5x20mm fuse option added for Euro buyers

So over the years people have asked about the old version, made by someone else.

It's probably time for an updated one. This one is a bit different. You may notice it does not have following capacitors after the choke. I have tried both ways, and my preference is without the following X2 capacitors. Also the capacitors prior to the choke are not varied in size because overall capacitance is more important - and they won't randomly resonate with each other.

The other major change is the addition of bypass resistors for the chokes. These don't ruin the filtration, but they do a good job of quieting the chokes that can get excited by different combinations of things on the mains.

View attachment 1043981

Gen1 w/comoco's
IMG_1974_1_22.jpg


Here's how it is different in settling time from the original.
Fo_felix_vs_felix.png


Here's a comparison between resonances.
Fo_felix_vs_felix_resonance.png


*2oz copper PCB (1oz is standard)
*Weco 983ZD terminals, copper alloy and can accept 2 wires for daisy chain. These are also safer, particularly if you use solid core wire that otherwise likes to make cold solder joints you can't see.
*X2 rated capacitors for safety, 4x 0.47uf. They are alternated for CFC (capacitor field cancellation).
*Discharge resistor for X2 capacitors
Coilcraft Comoco choke w/fuse or Bourns 8120/8121-RC choke w/o fuse & 15/16A/20A() max sockets
*Fuse clips are beryllium copper 3AG & 5x20mm options
*120/230v operation (parts & pcb)
*Mounting holes are sized to work nicely with M3 screws and standoff kits
*Size: 2.25x4.25in

The Weco 983ZD are preferred terminals, but not always available as individual sale. For this reason I'm going to include them in the price of PCB, so that I can meet min order requirements for them and save everyone the shipping.

Price: $14ea ($10 per filter board, $2 per Weco, 2 needed per board)

Shipping: $11 US, priority USPS box
$20 CAD
$22 General international padded envelope (prices may vary due to a crazy world)

If ordering over 4x boards there may be an additional $10, depending on destination.

Need 32 filter board commitments to order.

drkingweeb 2

voxxonline 3​

poolball69 10​

pcgab 4​

chiily 2​

dzoli 4​

yardbird 6​

Beeah 6
Yoaudio 2
Geoturbo 2

rickmcinnis 5​

Dave_MN 4​

rothay 4​

pinnocchio 3​

ZzerO 9
ElliotA 6

pedrop 4​

LongRanger 4​

wushuliu 6​

hybfish 2​

Garytr 4​

DiyFan 3

STAX DAC Talent

So not sure where I'm going with this. Lets start with that.

Bought a STAX DAC Talent (despite my misgivings about SPDIF) and it is rather nice although old at this point

As is my S.O.P. with 30yr old gear, I've swapped out electrolytics. All THREE of them 😀. In this case with "shiny" Nichicon ones. To be rewarded with a little red LED coming on in the power supply section (AKA I didn't notice it before) I assume this is good.

So case off, the chipset is mainly:
  • YM3623B
  • SM5803AP
  • V-12M288
  • PCM63P K 😍
  • AD845
Much opto-isolated glamour! with pictures

I have questions though... Not least of which is normal/direct !?! What does that even mean...

Information is hard to come by for this although I guess the money was spent on the digital rather than the analogue side 🙂 it works well.

Can this (semi) sensibly be updated. I know there is an 'upgrade' for the SM5803 to DF1700 - worthwhile??

I also have already the ability to swap PCM63's to PCM1704's But it seems completely unnecessary.

Andy

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MLCC Instead of Electrolytic for Power Filtering?

Hi All,

I have been building my guitar pedals using a mixture of polyester film caps for NF, N0G ceramics for PF, and Electrolytic for large UF (power filtering). I want to build guitar pedals and preamps for personal use that will last forever, and so am thinking about using MLCC when possible for larger UF values.

I see this MLCC offering from TDK on mouser that has 47UF with 25v rating.
https://www.mouser.com/ProductDetail/TDK/FG26X5R1E476MRT00?qs=vNwBHymccZ/EuAwGgXhUgQ==

I like this because I can buy in bulk without worrying about them expiring and they should basically last forever. I have heard ceramics are bad for audio path due to piezo, but am I correct to assume its okay for the large value power supply filtering with some smaller film caps thrown in as well?

Thank you!

My System Has Gone Horizontal Hybrid for 2023

Back in early 2020 I revamped my old Dynaco tube amps with the VTA mods from Tubes4Hifi, and wired them in a vertical bi-amp configuration using two stereo amps. The VTA mods and bi-amping took the system to another level, and I was pretty happy. After hearing the Magico S5 MkIIs at Convergent Audio, i started to think the bass didn't have quite the control and slam that it could.

Sometime in March 2023 the system got reconfigured again, but this time into a tube/solid state hybrid horizontal bi-amp setup. I see it as the best of both worlds. Each amp type doing what it does best. It helps that each driver of my 3-way speakers has it's own input, so are fairly conducive to bi-wiring, bi-amping, or tri-amping.

The twin stereo Dyna/VTA 70 tube amps got solid state rectifiers, are sporting new Tung Sol 7581A output tubes in triode, and are now run as single channel mono blocks, which still leaves me with the outstanding separation offered by vertical bi-amping. They're only powering the 5" midbass and tweeter now (which have a natural acoustic rolloff at about 80hz). The tube amps see an easier to drive 8 ohm load (vs 4 ohm) and lighter woofers...they sounded notably clearer immediately. (a pleasant unexpected side effect!)

The solid state amp is a vintage Kenwood KA-3500 integrated amp that only drives the main 8 inch woofers from 80hz down. (It also feeds the active subwoofer with a high level signal). A couple of months after experimenting with this setup, I added an active low pass crossover ~ 80hz, then followed up by bypassing the passive low pass crossover to the woofers a few weeks later. Yep, there's more bass control, more detail and slam, and it really lets the transmission line shine.

The signal from the preamp gets split between the tube amps and the SS integrated amp. This configuration treats the Lazarus preamplfier as a master volume for all the amps, while the integrated amp has it's own volume control for everything below 80hz. I can vary the output of the woofers and sub separately relative to each other, and relative to the tube amps that feed the midbass/tweeters. In addition, the active crossover has it's own gain settings, so there's lots of flexibility to dial in low frequencies however I want, and not impact the vocals of the midbass driver.

Some new copper inputs for the mids and tweeters, new Furutech OCC cables, and a new Hagerman phono stage round out 2023 as a successful year of fairly aggressive upgrades for relatively low cost. The system is all coming together nicely just in time to enjoy a wonderful Christmas music season. All in all the changes have resulted in easily audible improvements on multiple levels IMHO. Overall clarity is better, and bass is notably tighter and more dynamic, and provides the ability to fine tune bass output. Cost for used the integrated amp and active crossover were under $100 (way less than new tubes!). I'm extremely happy with this setup, and am glad that I went down this path.

Horizontal bi-amp layout.JPG
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How to repair voice coil on Rockford Fosgate R2S-1X10?

This is my first sub and I totally blew it! It did good service for almost 2 years, but I'd rather fix it then get a new one!

I took it out of the enclosure and the cone is good, its not cracked, and the "spider" seems good too, I finally came across this video
Login to view embedded media and it sounds exactly like how mine sounds.

So how do I do fix it? It's a very compact sub and when it was out of the enclosure there were no screws and I have no idea how I would take it apart. What parts would I need and how much would it cost to repair? Are there any guides for this kind of sub? Or at least for some other compact 10 inch sub?

Thank you diyaudio community

DIY Flat Power Cable

Hopefully this is the right forum for this but I am looking to build or buy a flat IEC power cable as I need to plug it into an outlet inside a cabinet and run it under the glass cabinet doors to my speaker's power supplies. I looked all around for a commercial solution but was unable to find anything but I assume someone has built something similar using bulk ribbon cable or something like that. Any tips or advice? Thanks in advance!

Tube tester board

Hello.
I have this little nifty tube tester board, it can test a large variety of small signal types, all the classic audio tubes.
Its totally unasembled the only parts that I have for it is the preprogrammed atmel chip, the 20x4 lcd display, and the rotary encoder bourns
ECW1J-B24-BC0024L. All other parts are up to you.
I put here link to folder that contain all necessary info for assembly and use. https://drive.google.com/drive/folders/18TcbD3Y83YUaoSefdYeP8lOa8BGxVGti/
I'm asking for 30 euro, that's the cost of pcb only
Last photo is of finished product.
Ps. Just turn the rotary encoder and choose between 99 programmed tube optimal values and press test, it's as easy as that. It's a proven concept.

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DIY amp for LXMini tops

Hi all! After building a couple headphone amps (Peter Millet's NuHybrid and an ACP+), an ACA, and an lxmini crossover, I think I am ready to tackle one of the FW or BA projects to power the full range tops on my lxminis (crossed at 700 Hz). Currently, my signal chain is either an Apple AirPort Express used as a streamer or Pioneer L-71 turntable, into an Emotiva PT-100 preamp, into the analog lxmini crossover, into an Elan 660 power amp (a 6 channel distribution amplifier running LM3886s), with 4 of the 6 channels bridged to provide about 100 watts to the woofers.

I am hoping to build something that can deliver 40 watts at 4 ohms to the Seas Prestige FU10RB H1600-04 4" Full Range drivers handling the mids and highs. Due to the fact these are 4 ohms, I believe that rules out the single ended options if I want to be able to play the system full volume. So I have been considering buiding an F5, F6, M2X, BA-2, or BA-3.

I have a spare quad of TSJ74 (Idss 6-8mA) that I ordered thining I had burned one out on the ACP+ (I had not), so it would be great to use them or 2 of them, but that might be tough to match.

I listen to a wide variety of source material including alternative country, 90s and 00s indie rock, 60s and 70s classic rock, punk, soul, hip-hop. I love a good drummer that can lift great artists to alltimers most of all (Janet Weiss and Sleater-Kinney, Topper Headon and The Clash, Levon Helm and The Band, Al Jackson Jr. with the Stax Rythym section, Roger Hawkins of the Swampers at FAME studios), so definetely looking for something that can resolve cymbals well.

Regarding distortion signatures, I have found that using the Millet NuHybrid into the ACA (with full range MarkAudio speakers) was too much 2nd harmonic. Complicated drum licks and guitar passages were too muddy. Feeding the ACA with the ACP+ is more to my taste, though at times there can still be a touch of muddiness at higher output volumes. This has me leaning towards buildign the F5 or BA-3 since I could adjust this some to my taste, but I'de love to hear what others recomend in this case.

@6L6 I have read that you use lxminis, so I'd especially curious about your thoughts here for a good fittign amplifier. Thank you all for your advice.

For Sale AYA II DS DAC Audial, partly populated with TDA1541A

Anyone interested? I have documentation how to finish this fine DAC AYA II DS rev 0.221115
Fixed price 125 Euro

Complex chips included;
1x Q310 TDA1541A (supplied by me)
1x Q205 CS8414-CS (already supplied & soldered by Aurial)
1x Q208 74HC590D (already supplied & soldered by Aurial)
4x Q409-Q412 OPA861-ID (already supplied & soldered by Aurial)

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Service Manual for Vincent SV-233 Ampilifier

Hello people,

I am looking for a service manual for a Vincent SV-233 amplifier (the one with the 3 inputs) and have already searched the whole internet.

But it seems that there is no such thing for Vincent Audio devices.

Or do any of you have information about a service manual for a Vincent SV-233 ?

I would be happy if there was something.

Greetings

Dirk

Turntable motor starts spinning when arm returns

Hi all , wondering would anyone be able to help me troubleshoot this please ?

I have a sharp rp30 turntable and after the arm returns it's stops spinning as it should.
But 2 or 3 minutes later the motor will start spinning again even though the arm is returned . I first thought it was a faulty switch but replaced that and still the same .

Visually everything looks fine and nothing looks blown out inside .

APEX AA9MD

Hi

i want to sort the APEX thread a bit.

here is my BOM for AA9MD, schematic, layout

btw...
i am not happy with this "Ultimate 100W audio"... thread because without search you find not so fast ....

edit:
Apex directory done by XRK (thanks)Apex directory

link for Transistors: (found during search at FH9, FX8 and FH9HVX) Transistors
and
here: VAS and driver transistors

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Hypex FA123 keeps dropping USB connection

I’ve have an issue with one of my two Hypex Fusion FA123 amps
For clarity I have this amp connected to my left channel speaker.

Left channel amplifier

I had designated as the FA123 (that began displaying the problem) as the “master” of the two amps.​
The amp disconnects 6 or 7 seconds after the Hypex Filter Design software connects to it via USB.​
If I have the software open and plug in a USB cable between my computer and the amp, the device connects, then after 6 or 7 seconds it disconnects. If I unplug the USB cable from my computer and plug the cable in again, the same thing recurs.​
Additionally no sound comes out of the amp anymore.​

Right channel amplifier:

I connected the USB cable to my right channel amplifier (my other FA123).​
It connected as it should.​
I reset it as the “master” and connected it by S/PDif out to the left channel amp’s S/PDif input.​

Returning to the left channel amp

I again connected the USB control port to my computer.​
The USB continued to disconnect.​
It did give me several seconds to change the configuration of the left channel amp to “slave”.​
The setting appeared to hold after it disconnected and I would again unplug then replug the USB.​
I did the same thing to designate S/PDif as the input.​
No sound out of the amp.​
It almost seems like the "master" amp can't communicate with the problem amp and thereby can't control the volume either.​

Note: I've rebooted the computer, the software, and the amps numbers times.

I've contacted Hypex support, but won't likely hear back anything until next week.

Some questions:

Does any way exist to manually|mechanically reset the amp?
Can one replace the USB socket?

If the amp won't work any longer could I repurpose its parts (amplifier boards, DSP|DAC, power supply) by removing them from the plate and setting them into a Ghent chassis?

Thoughts and guidance appreciated.

- Andreas

Where to start? First project idea advice wanted

Hi all!

It's my first timing posting here and would love some help/advice/guidance to get started.

Things started a few days ago when a friend of mine gave me his old LG 5.1 speakers. The DVD/amplifier broke and the speakers were sitting in his house for some months, and they are now mine. He doesn't have the DVD/amp anymore.

Now that I have the speakers and sub, I would love to put them to work in my living room, but I'd also love to assemble the amp on my own as a first project. I've searched a bit but have not found much info on how to build a 5.1 amp. besides some tutorials that are lacking some information.

This is a reference project that I liked, but I'd love to have some more input options, such as an optical one to use in my TV.

Here are the amp and speaker settings from the manual.

Thanks in advance 🙂

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Arcam A65+ high DC offset and thump sound, help please.

Hi can anyone give me advice on how to repair an Arcam a65+, The symptoms are, thump sound at turn on or off and very high DC offset of over 700mv in the right channel it plays fine for ten minutes and then switches off and comes back on and carries on playing. The left channel is fine.
If someone can give me advice on where I need to be looking that would be great. Thanks.

triode 26 as driver for triode 45

Triode 26 and 45 get lots of praise, and the cost is a bit less than tubes like 2A3 and 300B.
There are easier tubes to build with, like 6SN7 and EL84 etc. but I'd like to wind the mains x-former, filter choke and the OT x-former myself, so why not go the whole distance with the 26 and 45 while I'm at it.
And yes,-I have wound a mains x-former and OT for a Vox AC30 guitar amp with great success so I'm not completely green with such work so I know what to expect to some degree.
But the question is how does the 26 cope with driving a 45 in a SET configuration?
I like the idea of using only two stages. That's the beauty of tube amps,-they can be very simple and have a short signal path which I think is important.
Is this possible without implementing an interstage transformer or adding a whole bunch of circuits around the 26 stage?

For Sale F6 Clone; WHAMMY HPA/Preamp; Lehmann Audio Black Cube SE II; TT Pioneer PL-30L II

Hi Guys,
I regret to say, but I have to sell my beloved mostly-DIY system, as I am moving to Canada from Poland on the beginning of next year. It gave me so much pleasure, but I can't take it with me across the ocean, unfortunately. I believe that there is quite small amount of people form Poland here, but who knows... maybe somebody is looking for something and is close enough to me. In most cases I can't ask more than components+chassis/cabinet cost for each component, so the prices are pretty reasonable in my opinion. To be honest, all these stuff should cost much-much more... but only thanks to the DIYaudio community, The Papa, Wayne, etc. who are willing to share their beautiful designs with us.
So, here is a list:
Turntable: 2900zł/ 675Euro Pioneer PL-30L II with upgraded tonearm wiring to Cardas from a cartridge to RCA connectors (replace shitty original built-in signal cables). Tonearm pipe is not detachable anymore;
Phono Pre: 2800zł/ 650Euro Lehmann Audio Black Cube SE II, all original, working perfectly;
Preamp/HPA: 2900zł/ 675Euro WHAMMY in custom chassis (3 inputs; 1 output), with Jantzen Audio SilverZ coupling capacitors, awesome Sparkos Labs SS3602 Dual;
Amp: 4800zł/ 1120Euro FirstWatt F6 clone, all original parts&chassis, quite Toroidy AUDIO transformer;
Speakers: 6500zł/ 1510Euro Troels Gravesen's Discovery 861 with Californian walnut veneer - wonderful speakers which pairs with F6 beautifully.
Total is 19900zł/ 4630Euro.

I also have Hana SL cartridge. Used carefully for ~200-300h, did't add it to the list as I can take it with me. But it could be sold as well.

Four 90x60cm grey rock-wool sound absorbers; 2 pairs of Neotech OCC copper RCA signal cables - GRATIS if somebody will be interested to buy a whole system.

DIY part was finished about a year ago, except WHAMMY - about 2 years ago. Everything worked beautiful with no issues. With no or almost no signes of use. I made it for myself with no intention to sell, but my situation has changed.

I don't think that shiping is possible. The only option is to pick up by yourself. I am located in Poznan, Poland. Some 3h ride from Berlin for example.

Send me a message if you are interested. Additional images could be sent upon a request.

Regards,
Nicolas

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For Sale 46 Amp from Japan

This is a lovely sounding amp. I have installed Finemet c-core transformers . There is a switch for 4 , 8, 16 ohms . Copper top line Jupiter coupling caps. Western electric 717 input tubes
I made it look great . 1 glories watt. Dead quite. This is a 100 volt amp will have to be ran with a step down transformer , or a vary-ack .
thanks Rick
1325$ and shipping

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Need advice for affordable stereo amp boards to play with active x-over (8ch total, 4 x stereo)

Hi,

I have toyed only with the full-range speakers until now and now want to start some multiway speaker DIY project, at least 2way, but also up to 3 ways + maybe 2 passive subs . The idea is to have PC as sound source,, 7.1 sound card as DAC, and JRiver, or other software as active crossover, sound level control and everything else. Want to build some kind of quick and dirty 8 channel amp but with decent sound quality. Budget is very VERY tight, but TPA3116 level of quality is enough for me. Probably everything will be bolted on some kind of wooden board with minimal protection from pets and kids.

Need advice for the exact boards to choose. Probably I will be happy with most of the popular class D offers, as I liked the 3116

Requirements:
-4 or 5 identical stereo boards, ready to use, no soldering of components
-Up to 10W per channel is enough. It is for personal use and to learn active x-overs. I really doubt it will be used for parties or similar
-12V compatible boards preferable, as I don't want to stick with bunch of electronics which operate at less popular voltages after the project is dissolved. Will be powered by MeanWell 12V 150W supply.
-Softstart board or other means to avoid driver and eardrums damage with on/off popping noises. Can be built into the stereo boards or separate

Nice to have:
-12V trigger board compatible. Little wet dream for future project
-Maybe big enough high WAF metal box to accommodate all the stuff inside. I know this is a separate thing, but I will mention it
-Ability of the amp board to operate in mono mode with double the output power for subwoofers.

I live in EU and have not so good previous experience with Aliexpress and likes, so prefer to chose from local supplier, even if it is a little more expensive and less options to choose. Also the import taxes will ruin all the fun.

The budget is 150-200 EUR with shipping. Maybe little more with nice and shiny box


Are these components below good bang for the buck in my scenario?

-Power supply
Mean Well LRS-150-12, 150W 12V ~25EUR, bought locally

-Nuts, bolts, wires, plugs, nice 230V front switch ~35 EUR, bought locally. Will avoid expensive terminals for now.

-5 amp boards: 3 stereo pairs + 2 bridged subs or 5 stereo
with TA2024 chip - 14 EUR each, ~70 EUR for all, in best case, in other places the same board is ~24EUR/piece, so ~120EUR total
https://www.audiophonics.fr/en/ampl...plifier-module-t-amp-ta2024-2x15w-p-7371.html

-Softstart power-on ~16EUR
https://www.audiophonics.fr/en/soft...rt-module-230v-15a-for-amplifiers-p-4415.html


Total in best case scenario is ~160EUR, and ~210EUR in worst.
I will have 50EUR left for the shiny aluminum box.

Did I miss something?
Should I go for TA3116?
Please correct me. Any advice is very welcome.



Thank you!

ADAU1452 PLL unlocked

Hello Everybody,
I'm just building my DSP design with ADAU1452 and I have issue with PLL lock. It's unlocked all the time and I can't figure out why.
The PLL filter voltage is 3.25V, very close to 3.3V PVDD voltage
Master clock 12.288MHz is working
It's made on 4-layer PCB

I've attached schematic, PCB layout of PLL and Sigmastudio status

Every suggestion is appreciated

Thanks

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APPJ New mini vintage Tube Amp PA1501A

The PA1501A is the latest mini tube amp of APPJ in 2015. The design of the amp is new and unique.

The 6AD10 is a indirectly heated double pentode and this amplifier pentode was designed as an FM detector in television receivers in the old days. APPJ researched 6AD10, deveopled and specially designed the circuit as this stereo audio amplifier PA1501A. APPJ seriously tested and selected NOS 6AD10 in pair and provided with the amp. Now It is very easy to buy 6AD10 tubes for spare or replacement and the price is cheap.

There are two colors of chassis for options: Black and Silver
Universal input voltage: 100V-250V AC
No power cord and no interconnect cables included.
One year warranty

Technical information of 6AD10:
6AD10 @ The National Valve Museum
http://www.r-type.org/pdfs/6ab4.pdf

Spec of PA1501A:
Tube: NOS 6AD10 x2
Power Output: 3.5W+3.5W @ 8 ohms
Frequency Response: 30-40Khz (+/-1db)
Input Sensitivity: 500mV
Signal-to-Noise Ratio: -80dB / 3.5W
Residual Noise < 0.5mV AC
Input AC Voltage: 100-250V AC
Power Consumption: 38W
Input Impedance: 10K ohms
Output Impedance: 8/6/4 ohms (Z11-EI48*24 Output Transformers)
Dimensions: 160mm (w) x 134mm (d) x 125mm (h)
Weight: 2.5kg
Input: RCA Jacks
Output: Banana Jacks
AC: Standard IEC Jack with Fuse protection (2A Fuse)

Price: US$189 + shipping cost

Promotion: we now offer Furutech TF audio Fuse 20mm 2A at free with our PA1501A amp as spare for performance upgrade. The promotion peroid is upto 31, Dec., 2015.
TF Series Audio Fuse | FURUTECH

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Asymmetrical crossover?

Anyone here have any insights on asymmetrical crossovers? I'm looking to build a new set of 2-ways specifically for my living room with the idea being similar to the GedLee speaker lines Earl Geddes used to make and sell. I found the waveguide thread and software by mabat, and will be utilizing that in the design. But the topic is about the XO.

In my imagination, mating a high efficiency 15" woofer with a compression driver requires a low XO point. I don't think I want too steep of crossovers based on past experience w/r/t off-axis transition, though I suppose if I'm matching off-axis response of the woofer to the waveguide at the XO freq, I may not care as much. Since any compression driver will be so much more sensitive than any high efficiency woofer, I'm not concerned about running the CD lower than often happens. With that in mind, if I wanted to combine a higher order low-pass for the woofer with a lower order high-pass for the CD, the CD does that have any design merit? The idea is to roll off the woofer as it starts getting to "beamy," and letting the CD contribute a bit down lower in conjuction with the woofer. For example, 18 dB/octave LP with a 6 dB/octave high pass. I haven't researched this much, and it's been many years since I was designing speakers, but if I'm remembering correctly, those two filters should allow me to swap polarity on the CD and keep the signals in phase while they're summing together. I know that I won't be able to sum to a completely flat response in doing so, but can choose two frequencies to minimize any bumps/dips to be acceptable.

Anyway, does anyone have any experince with something like this? Things to look out for? Reasons it's a terrible idea?

0-72 volt 0-30 amp switch mode PSU

Hello.
Two powerful switch mode supplys for sale powernet adc7520/48
Was gonna be used as bench psu, but off they go.
Can do master/slave series parallel.
Asking 150 euro per psu.

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Grid Current, how much?

So, in a recent debate with some friends, I am really wondering how much grid current is acceptable in a new and unused power triode like 300B. My very old and used specimens that I tried, their grid currents seem to be from below 1uA to 20uA at most, while on new eastern production tubes their grid current seems to be in the region of 1 mA! What value should be considered as ”acceptable” ?

For Sale ATC-SM75-150 Dome Midranges PAIR

I've decided to sell some of my collection of drivers as family life has taken over. No more speaker builds for a little while.

So, up for grabs is a pair of ATC-SM75-150 Dome Midranges. For those who don't yet know, I attach a link below. Without doubt, one of the best midranges made. As you might be aware, they have become unobtanium for the DIY market so I have looked after these. I also took them to a speaker specialist for inspection and thumbs up from him.

http://www.troelsgravesen.dk/ATC-SM75-150.htm

Price is AUD $1300 for the pair. Shipping at your expense (I'm in Australia). I will take to Pack N Send for packing.
EFT or Paypal plus fees

Pics as follows:

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RCF ART300A input PCB with green multipin connector

Hello,

I've been given 4 x RCF ART300A powered speakers to make 2 good ones for a customer.
I have two working., the usual dry joins and one module had both TIP35 and TIP36 dead short for the HF? 2.5A fuses blown.
All working. Not to let the other 2 go to scrap, I rather repair all 4 however, one is missing the input board and cable including the input shield.

As such, I'm after a complete input board with the cable which attaches to the main board and shield if anyone has a ART300A on their scrap heap?

Please let me know, we could agree on a price and postage to Australia.

Thanks

Shure M447 cartridge separated from top mount

Hi Everyone,

A few weeks back I picked up shure m44-7 cart mounted on a technics headshell, cost about $80. No tip, but I have a stylus I planned to use with it. It arrived with the bottom part of the cartridge loose from the top mount of the cartridge. It looks like the glue holding the two dried up. I was planning to send it back to seller, but wondering if it might be worth keeping - scrape off glue residue and put some superglue between the two. Would the fix be simple as this or is it not worth messing with?

Cheers,
-Art

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MARANTZ ST-530 Tuner

Hi everyone, I do not have big experience with tuners, until a week ago I acquired only two, Harman Kardon hk-715 and Marantz ST-400. HK-715 was a bit low on sensitivity so I got Marantz ST-400 which has improved signal reception, usable sensitivity 1.7 uV over 1.9 for HK715. So I was looking for something with even more sensitivity and came across Marantz ST-530 with claimed sensitivity of 0.7 uV. Sounds very good ( actually excellent). So I connected it to system and immediately I noticed difference to the other two: low end was anemic, middle- to- high a bit too pronounced. Is that characteristic of the tuner, or a fault ? As it was higher in the line to ST-400 I was expecting better result from its' predecessor. Any opinion, anyone has experience with this particular tuner, or Marantz tuners in general? Any suggestion on a GOOD SOUNDING mid priced second hand tuner?

Negative voltage on output of an OP249 stage

Hello there,


hope this is the right section (I thought maybe the IC amp area would also work).

I have built my first prototype on an double stage phono pre (double LT1007 for MC / OPA 2604 for MM and OP249 as 2nd stage), following an existing design from the German analog-forum.

I built the schematics in Eagle and created a PCB from it (so I know that the board matches the schematics).
Unfortunately, I just got a bug hum when I tested on MC, with a slight and very distorted idea of music.
So I checked everything with an oscilloscope, and while the MC and MM stage looks good, the 2nd Stage shows a very wired behaviour.
Even if the Jumper between the stages is open and all other ICs are removed, the OP249 got -12,6V DC on both output pins (1&7).
When I measure the socket, without the OP249, there is no voltage on the pins.

Power supply looks good (+14,8V on pin 8 and -14,8V on pin 4), and I can not measure any strange connection from any of the pins, all looks good.

Another thing that is strange: I pulled the input pins (3 & 5) to GND to ensure that I do not amplify any strange input.
While one output pin (7) stays at -12,6DC, the other one (1) went to +14,3V DC.

I already swapped the OP249 to another one, but it shows the same behaviour.

Any idea, where I should look?
Here is the schematics of the stage /don’t mind the wired dots, they are just for multi-raster for the foil caps):
1700512822860.png


Thank you already and with kind regards,
Felix

FS: ATC Setup with EC23 Active Crossover

Before I potentially part out this setup, I thought I would attempt to sell it as a complete set. I am located in Ottawa Canada, and would ideally like to sell within the eastern Ontario area. Shipping would be too difficult.

This is a loudspeaker that started off as the passive Proac Studio Tower, and slowly shifted towards an ATC SCM50. The original Proac Studio Tower had the ATC mid and woofer, and a lower level Scanspeak tweeter (now replaced with the Seas T25). After many years of research and sleuthing, I was able to put together the existing setup which includes the following:

  • ATC SM75-150 Mids
  • ATC SB75-234LC 9” Woofers
  • Seas T25-003 tweeters (these are the non-ferrofluid versions that ATC supposedly liked more than the T25-001 version)
  • SB Acoustics Satori WO24P-8 9” woofers (currently installed in the system)

So you get two sets of woofers to try - the original ATC or the new SB Acoustics Satori WO24P. The Satori provides lower bass, but does not have the power handling of the ATC.

The Proac Studio Tower boxes were modified with the following:
• Internal bracing added
• New Removable baffle to match ATC SCM50 layout
• Threaded inserts to fasten the baffle to the box
• Rear ported, but could be changed to front
• Speakon connectors used

Electronics: I was able to source a very rare ATC EC23 active crossover a few years ago. These were generally used in studios for the large SCM200 but use the same crossover points as the SCM50, 100, 150 etc.
- Currently set at 380Hz & 3.5kHz but can be changed through resister replacements
- PDF manuals and setup guides included
  • Comes with a plexiglass front (not pictured) which studios used to protect the values from getting changed by accident.
  • Adjustments include level, phase and has mute switches for each channel
  • Super quiet and works perfectly.

Let me know if there is any interest.

Price: $3200 CDN or $2400 US

And did you know that ATC no longer sells to the DIY market?

20221026_121731_HDR.jpg

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Atc amp pack schematics

Hello everyone !

I was curious if anyone has a schematic for any of the atc active amp packs? I just bought two scm75-150 mids from a forum member here and thought I would ask about the amps . Also if anyone has some old amp packs they might want to sell I would be interested also.

Also if anyone has cab dimensions for the scm50, 100 and 110 I wouldn greatly appreciate it , I’m still trying to decide which model to build for my room which is about 300 sq ft (25ftx12ft with 12 ft ceiling )

Thank you all for your help and time ! This is my first post here so if it’s in the wrong place feel free to move it.

Thanks!

Ethan

Why aren't there any great cone tweeters?

...or are there?

I've been wondering for some time now why nobody designs high performing cone tweeters. Sure back in the day the dome could sound more detailed or delicate or whatever. But by now I'd think some damn good cone tweeters (or mid-tweeters more to the point) could be designed, allowing a lower crossover compared to domes. Mostly what I've noticed is "full range" mini drivers with quite low sensitivity, no doubt due to trying to output "bass."
???

Switching power supply for phono pre

Good morning everyone. Happy new year 2022.
I haven't been on the forum for quite some time.
I have built several phono preampli diy of the well-known ones and not so much. VSPS300, VSPS400, Muffsy PP3, P06 ESP, Solidphono by TNT.
My question today is if these phono pre can be powered by switching source + 15v 0 -15v.
The question arises after I have seen the Cambridge Alva Duo fed that way.
It would be a lighter source, more economical and may not introduce noise of 50 / 60hz.
Greetings to all.

Threshold S500 MkII E series

These come up rarely and when they do, it’s usually the original version. There’s a big difference! Dual DC power supplies vs one, 4 large caps vs 2 caps.
This has the e-series upgrades and the latest optical bias improvements. This amp is a unicorn and you will not see these to often. The amp has no problem driving low impedance loads including ribbons.
balanced and unbalanced inputs
250wpc

This is a huge upgrade to the s300 as it runs class A watts much higher.
I also have a FET9 preamp and will discount the pair.
Will also discount local pickup.

Asking $2300

Pictures taken under a 6000lumen light so you can see everything, it presents itself much better under normal lighting conditions.

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For Sale ACA Mini as Integrated Amp

Selling my cute little ACA Mini in a nice cabinet with a alps volume pot making it as an integrated amplifier. Clearing some of the stuff to make way for new builds. This is essentials kit along with the pcb board plus transistors kit from the store. Nice quality binding posts, RCA jacks and wiring. Even hours of play it runs cool because of the size of the sinks. Dimensions of the cabinet being Width 10”, Depth 9” and height 4”. Comes with the 24vdc smps adapter from the kit.
Expecting $330 including shipping to the continental states. Will pack it nicely so shipping shouldn’t be an issue.

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How to feed a nice, complete preamp?

Hello, me again, with again a question that probably was amply discussed but I couldn't find it even not by searching for it...

So I have those super nice preamps (Wayne's Line Stage and Salas' DCG3 and DCB1), some supercool phono-stage and a just as cool DAC from Jean-Paul. Every one in their own boxes and that's ok.

Here comes: I am contemplating making a complete preamp, or even a supercool integrated amp with all needed functionality built-in: Phono, DAC, a line-input, Volume-Control and some gain...

What would be "the" correct way of building the PSU for a beast like that? Would I make one per "unit, thus having 3-4 PSU, transformers etc. in a box, or how are they usually designed?

I imagine having each stage with its own psu would be the most consequent but least reasonable way to go (especially when thinking dual mono, hihi), even if the PSU and amp would get their own box...
So would that then be a custom-made transformer with various secondaries (or two for dual-mono), and the circuitry gets split too?

As you can see, I am quite clueless.

LM317 and TL431 useful operating ranges?

The datasheet on LM317 states a maximum voltage between Vin and Vout at 40 volts and while this is mentioned a few times on here people seem to suggest not using them with higher supply voltages.

If I understand the datasheet correctly one could regulate say 35 Volts from a 50-60 Volt supply using a 317 or am I missing something?

On the TL431 its stated 36V relative to the anode/ground and max 100mA so theoretically I should be able to regulate say 35 volts and 50 mA using these but it does not work, they break (newer ones almost all but a batch of 20 year old ones coped much better)

So what would work for the TL431, am I pulling to much current through it or is 35 volts to close to its maximum?

McIntosh MC250 service manual for serial number 13L04 or 18L04

I've downloaded a number of PDF versions, but none relate to the particular unit I have on my bench now.
I need to identify some parts that have proprietary p/n on them.
The serial number is partly defaced, so my best guesses are in the title of this thread.
Can anyone identify this amplifier and the correct schematic and parts list?
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