I'm building a DAC and I'm looking for some advice on power supplies. I noticed that some designs focus on using very low noise LDOs. Is there really a noticeable difference vs using jellybean LDOs with proper decoupling? Which characteristic of LDOs is more important (RMS noise, PSRR etc)?

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

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 🤞

Any builders of the Troels Gravesen Faital 3WC - 12? Impressions on how the build went and the sound after they were completed?

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





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






This is the speaker I am looking at replacing

@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?

Click to expand...

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





dave

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

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.

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!

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.

Click to expand...

View attachment 1043981

Gen1 w/comoco's


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


Here's a comparison between resonances.

*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

Click to expand...

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

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

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!

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.

Hello,
I am looking for a replacement 12" Bass Driver for a pair of Goodmans Goodwood Speakers I have just inherited.
If anyone has one or knows where i can get one from, that would be great.
I am in the UK.

Thank you

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

finished M2 Teabag boards for sale with matched 2sk1530 2sj201. I build two M2 pcb sets for balanced mode but only use single ended

Looking for a Sony RM-P2000 remote used with TA-E2000ESD

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!

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.

I'm always happy to have someone verify my math.
I'm looking at an OPT for eight 8417 in parallel for 300 watts into 8 ohm secondary.
Primary impedance should be around 1000 ohms ??

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.

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)

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

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 .

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

Hello,

I have a Mark Levinson 436 that has a bad transformer on the AC board. I need a replacement transformer. So I am looking for a Mark Levinson 436 or 434 AC board with a working transformer.

If you have one that I could purchase please message me.

Thank you.

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


Right channel amplifier:


Returning to the left channel amp


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

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 🙂

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 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?

Post removed because of severe safety issues.

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

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

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!

Hello.
I have theese 4 old but unused spools of multicore sc96, it is 0.25 mm thick, and I believe silver content is around 3-5 percent, spools are 250 gram each.
Asking 50 euro for 1 or take all 4 and pay for 3.
EU only

​

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

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

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?

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.

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” ?

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:

I want to simulate a 2way crossover network I designed through PSpice and measure impedance, but I don't know how.

so i have what it looks like 1mm(measured using a cheap digital caliper) diameter enameled copper. How do I make an inductor out of it? I know I need to make a "loop" but unsure on how big or how many turns.

I searched the net but didn't see anything helpful.

thank you.

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

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

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?

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):


Thank you already and with kind regards,
Felix

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?

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

good morning friends, I would like to know if it could be a sonic improvement to change the NPC SM5803 clock with other more recent and compatible ones in the circuit of my Marantz CD 16
thanks in advanceuigi

...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."
???

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.

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.

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.

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.

assume it might sound decent with a little helper woofer

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?

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?

I got 15 of those
there is a plan to use them in a 2 way design
Woofer i will use does very well in the midle area and its a real 100W woofer
can anybody share his expirience with these tweeters ?
https://www.audiophonics.fr/en/twee...bSB_7gQ--mzGVRJWeh2wjmVjdBW6UbeUG1pEjyye0NE0I

Need to know one more thing
does this tweeter require some enclosure from behind ?

I have a couple of ICEpower 500 modules here that need gate drivers. The drivers on the board are marked as 2100 which brings me to the ISL2100 datasheet here. This is where it get's confusing. Not only am I having a hard time finding the ISL2100 in an SOIC-8 package, page 3 of the datasheet tends to suggest it isn't available in this package. Only DFN. But the board is definitely using SOIC-8.

Was this a custom package order for ICE? Has anyone found a substitute for this that works? The datasheet states this is a pin compatible improvement upon the HIP2100 but I don't know if this design depends on those improvements. Am I overlooking something obvious? Thanks!

Apologies if I have missed a previously posted answer. However...

When extending amplifier performance to higher power the F5 is typically chosen as the starting point; F5, F5 Turbo V1, V2, V3...

Assuming that one will need to use multiple matched devices to spread thermal loading and that one wants near identical performance from all devices to provide best cancellation of `errors', wouldn't it be a lot easier to find near identical performance using a single device type rather than try to match complementary pairs?
Wouldn't the F6 be a better starting place?

Is the answer as simple as the problems introduced by trying to get well matched complementary pairs are outweighed by the errors introduced by adding a transformer?
Hoping for illumination,

I'm trying to fix a Renkforce E-SA9 that is noisy on one channel. I know the amp is crap and worthless but I'm determined to fix it.

The right channel works fine but the left channel is noisy. The source signal can be heard but is drowned in hissing white noise (no popping or crackling). This is the only schematic I can find for the amp (attached below): Renkforce E-SA9 Stereo amplifier 2 x 12 W Silver (metallic), Dark brown | Conrad.com It's not quite accurate since some of the caps are electrolytics on the schematic but on the actual board are surface mounted non-electrolytics. Some other electrolytic values are different.

I'm using a signal generator app on a tablet to send tones. Probing around with an earpiece I can hear the noisy signal on the output cap of IC2a pin 1 (red arrow below). There is no noise on the same cap on the right channel (green arrow) which uses the other opamp in the dual package.

I've replaced both JRC4458 dual opamps and the red arrowed 10uF SMT cap. I've lifted the supply pins 3 and 5 of the output LM1875 in case the noise was coming from the output amps. The noise is still there.

Any ideas what might be causing it, what might be worth changing?

many thanks

About 15 years ago the church I go to was doing a clean out and they were gonna toss a pair of Argos column speakers in the dumpster so I asked if I could toss them in my car instead.

Maybe a year or two later I gutted the drivers and used the following drivers.

Four Dayton Audio DC-200-8 8" woofers wired in series/parallel for an 8 ohm load.

https://www.daytonaudio.com/product/25/dc200-8-8-classic-woofer-8-ohm

One Pyle Pro sealed back 8" midrange.

One Eminence APT-80 tweeter mounted to an adapter made out of a piece of wood so that it could mount to the 8" hole properly.

I used an Eminence three way crossover, a zobel network on the woofer and midrange and the proper resistors for the l-pads.

I proceeded to seal the cabinet up as best I could.

Until recently the speaker worked fine and I even built another one last year.

I recently found I had done the l-pads wrong so in the process of removing the back off one, the cabinet had to practically be destroyed.

The cabinets were made out of some type of chipboard or something not really meant for being hauled around like I use them as they were intended to be mounted to a wall for a few decades.

I used a third cabinet I have as the replacement.

I then realized only the original two (got two more for free for fixing an old Peavey powered mixer) are the exact same size and the other two are slightly different sizes.

So I came to the conclusion that it would be best to get two proper cabinets built for two reasons.

1. Much better durability and the ability to add handles and casters.
2. Can go with a larger cabinet for better bass response.

As is the speaker produces decent bass to about 35Hz and gradually rolls off below there.

Also the current cabinets when powered on about 200 watts sitting on concrete will walk backwards when lower bass is being played.

I can post measurements of the cabinet when I get home from work.

The cabinets just do fit in my car lengthwise. Given I'm using a small tweeter I could reduce the height of the speaker by maybe 3-4"

The speakers are arranged vertically and the cabinets are not much wider than the 8" drivers.

What should the width of the cabinet be?

I'd also like to make these powered speakers and install a decent quality full range plate amp that can put out at least 240 watts (higher wattage if used with a limiter) if there is such a thing. I'd recess the amp in the back panel so that the controls will not extend past the back panel of the speaker.

I know the depth of the cabinet will have to be increased for the plate amp to be able to fit inside.

For the drivers I may mount them from the front using t-nuts and will use grills that fit each speaker.

I may also use t-nuts for the rear panel so that I can easily open the cabinets if need be.

Also what should the thickness of the wood be?

So, I'm retired now, supposed to have plenty of time for all my left-over projects. Not.

However one of my projects in 1993 was a tube amplifier, which I designed my self using manufacturer data sheets for the tubes.
Once completed I found that it had a perfect electrical characteristics, I used only audiofile components, connected the amp to good speakers. And I did not like the sound at all. And the wife did not like the size (2 monoblocks @ about 10kg each). Now 30 years later, I would like to try to complete the project.
Since I have totally forgotten how I calculated the amp (I found tube graphs with lines drawn across them, some resistor and gain calculations, harmonic distortion calculations) but now I'm clueless how I did that 30 years ago. I still have a lot of spec sheets.


Each monoblock is composed of three stages, a floating paraphase input stage which delivers two 180 degree out of phase signals. It uses a 12AX7-WA milspec double triode. The second stage is a double triode (6SN7GTA) which just amplifies the 2 signals for the endstage, a pair of 6550A's in ultralinear mode. The output transformer is tailored for the 6550's in UL mode. I recall the amp working stable (no oscillations)without feedback circuit, and covering 20Hz-20kHz. But since i recall experimenting with FB I'm not sure how linear the amp really is.

It appears that since 1993 there have been a few technology changes, such as the invention of the internet and the development of something called SPICE.

After this introduction I'd like to pose my real question. Since I cannot recall all calculations, would SPICE help to simulate the circuit?
Doe SPICE work well on a Mac? And most importantly, where do I start?

I would have to do some reverse engineering on my own design to get all the componentvalues and the final diagram though 🙂

TIA,

Johan

Looking for the oem crossover for the NHT VS-2.4, or the two coil values in the crossover. The DCR of each would be a plus. TIA

Deep into a multiyear complete rebuild of our to be very high end(but very reasonable cost) full time RV and just no time or brain power for DIY right now(maybe ever🙂 I just need a decent streamer, plug and play, and have seen reviews of the WIIM Pro Plus with the supplied wall wart, IFI SP and more costly linear supplies but no budget for an expensive one at this time due to the money pit we live in and love.

Looking for a good assembled PS board, I can make up a case easily enough, or in a case, best for the money I can get but want to keep it under $100 so please help me out with your recommendations, it will be much appreciated🙂

------
I have quite a bit of great audio gear, DIY and factory including horns, tubes, D class, OB, etc.....and always roll my own cables for decades now. I be testing many speaker designs to see what I can make work the best when I get much more of the remodel done as well as playing with DIY amps, maybe DACs, streamers, etc but that is at least two years away.

------

NOTE: I am highly shielding the RV and only plan to use wired internet, blue tooth on certain occasions and no wifi so the WIIM might not work with our Tablet or phone but have not found that out yet, I would consider BT if possible or go wired so please let me know of any advice you can offer.

Thanks!
Rick

At what point does a windowpane brace become too restrictive, cause resonant cavities, etc... The best I can reason is that is the brace is looked at as a port to the cavities it separates, as long as the "tuned" frequency of those windows (ports) and cavities are well outside the design Fs all would be well.

This question came to mind as i was looking through some pictures and came across my sealed UM-18 box. I will be opening up soon to add some stuffing so I could cut out some voids while I'm in there. Necessary?

Hi, I have to replace the volume pot on a tuner amp. I can use ALPS pot but most of the cheaper ones have four pins which includes one for loudness. Can I fit one and just ignore the loudness pin as there is a separate loudness circuit installed?

Teated on a Hickok TV7 , were 40 is low .
NOS TEST 60 + 60
date code F32 B3F1
125$ shipped in the USA

hi every one.my name is antonio.i own some vintage amplifier(solid state).i understand very little about electronic and diagrams.but i'm curious and i liker to learn.I hope I feel good here.
sorry for my very bad english.google translate helps me!

Hello all.

I was hoping some of you more knowledgeable people will be able to help me with the various options and best practices for my build.

I have almost finished building cabinets for my Tannoy MG 15's, I have built ~160L cabs in order to bring the driver up to ear height. Constructed from 19mm veneered MDF, pretty well braced and initially lined internally with dynamat and open cell acoustic foam.

I have left them as a sealed cabinet for a little testing during setup but am looking to port them and have been advised to tune the port to around 30hz.

Aesthetically, I would prefer a slot or rectangular port either low down on the front baffle or around the mid-point but wanted to make sure this will not detrimental to the performance of the finished speaker.

Thanks in advance.

I've got a set of KEF 104 (not the ab version) which I'd like to recap as the caps are buldging and lots of things sound wrong with the output.

The crossovers currently have Elcaps in the following properties.

1x4.2uF 50V
2x5uF 50V

I'd like to replace them with something of a similar quality (or better if not too expensive). Could someone please recommend a capacitor type and reasonable brand?

Falcon Acoustics have Solen "Alcap" caps which are rated to 400V. Would these be a good replacement? I'd get a 2 + 2.2 to replace 4.2 which they don't seem to have.
Or is there something more suitable?

Thanks

I have an active crossover and DSP. i am adding 8 inch subs to act as mid-bass for 1.6 Magies. How to I calculate gain, delay, and phase to integrate properly with LR speakers? XO at 150hz if that matters. Thanks.
I have REW and a Umik.

I have a Denon PMA 900v that sat for awhile unused. I opened the unit up and inspected it before trying to power it up. It immediately blew the main fuse (appears to be original) and the was a spark around main capacitors. I pulled the power supply capacitors to check them. 4 of the 6 capacitors read within spec ( I am going to replace them anyways) and 2 read dead short. The capacitors are 8200uf 72v (35mm x 70mm) electrolytics. I considered replacing them with 10000uf 100v capacitors but read somewhere about there being a concern that these amps do not have in rush control. Any advice, recommendations on suitable replacements. I plan to recap the entire amp as well while in the process; which brings me to my second question. I am considering replacing the ceramic capacitors in the signal path. What would be best in their place? Thanks.

Here we go all working - results are very good sensitive and selective. I can post the kicad stuff and code and alignment if interested.

I've been looking for an excuse to build a CBT for nearly a decade now. The thing that always stops me from "pulling the trigger" is that the high frequency performance of arrays is not great. It's a really difficult problem to solve that, because it's not as simple as adding a tweeter to an array, if you're going to add a tweeter, it will likely require dozens or even hundreds of tweeters to get the beamwidth of the midrange array to match the beamwidth of the high frequency array.

Another technology that I've had good results from is Crosstalk Cancellation. I've tried a bunch of different recipes to do that, everything from Polk SDA style arrays from the 80s, Crosstalk Cancellation via DSP using MiniAmbio and various Windows plugins. Opsodis is another oddball Crosstalk Cancellation scheme that never really went anywhere.

I was pondering these two topics, and it occurred to me that the two may be compatible. IE, CBT arrays have some issues, and Crosstalk Cancellation ALSO has a ton of issues. But the combination of the two may be synergistic.

I know this is an aging amplifier but any help would be appreciated.

I have acquired a used Parasound HCA-2200 Original Version. I am going to recap it soon. My question comes in regards to the OP Amp. I have read countless articles where John Curl and others say to either bypass the IC with a shielded RCA or to replace the OP Amp AD712 with AD825.

https://www.audioasylum.com/cgi/t.mpl?f=tweaks&m=56113
This is the best resource I could find on the LC Audio AD825 Type 1
https://www.octave-electronics.com/lcaudio/ad825.shtml
The website of course is overseas and I don't believe I can order from them.

I found this site for single to dual op amp adapter.
https://www.cimarrontechnology.com/product/browndog-020302-single-to-dual-op-amp-adapter

I have attached the original HCA-2200 schematic along with the Cimarron Adapters Schematic.

Can anyone verify that the Cimarron Adapter will replace the HCA-2200 AD712 op amp?

Anyone want to chime in on experience with these amps?

I plan on replacing all electrolytic caps. (Board and main)
I am going to change the resisters at R125 (R225) to Holco H4 https://www.diyaudio.com/community/threads/holco-h4-resistor-old-vs-new-how-to-identify.381120/
Per previous recommendations, I will remove the film caps on the main caps that are wired together.


Anyone recommend replacing rectifiers or resistors? Film caps?

Hello all,

It's a pleasure to finally make an account here, having lurked for many years. I was a musician first, then an audio engineer, a luthier, a film photographer, a teacher, a builder. I started dabbling in electronics troubleshooting and repair, having been first bit by the bug by an electronics kit in grade school, then getting into amateur radio, then building my own 86 PC very early on, and began troubleshooting and repairing my own bass/guitar amplifiers and pedals with the guidance of an experienced local tech. I got into instrument repair and building after that. I was a touring musician for many years in Kansas City and New York City. I started attending Burning Amp not long after I landed in the Bay Area in 2015. The crown jewel in my current listening system is a Pass Labs INT-60.

I am very much looking forward to BAF coming here to Petaluma this year and to all the future events and connections to come!

Here I am on the left with NY percussionist Annette Aguilar and frevo/forro legend Spok from Recife, at this year's California Brazil Camp in Cazadero, CA.

Is there ANYONE here from the southern Oregon area???

im looking for some local help.

thanks.

Hi all,

I've got 9 Quasimodo V4 PCBs to give away for free. Just pay postage. Shipping worldwide from Norway. PM me if interested.



Trond

Hi All, I've been a long time voyeur of diyaudio whenever I had a problem to solve so now that I've retired - as of May after 47 years in electronics - I thought I'd make it official and join the fun. We just moved cross country to North Carolina from California and I'm in the process of setting up my bench for repairing vintage stereo's - 1960-80's Marantz mostly as the first 3 years of my career was working for Superscope / Marantz in Chatsworth Cali. Never had the time while working but now.... And of course most of my test equipment is broken in some way or another along with being wayyyy out of calibration so that's first up - already had to fix a Tek 2465 scope for the fusable caps and exhaust fan. Looking forward to delving into the brain trust and hopefully I can add some knowledge to the effort...