I was looking at some phono stage designs and didn't like the typical asymmetrical stack of paralleled transistors, put in the feedback loop of an op amp.
It seems super unbalanced and would be impractical to get good THD performance at low frequencies since it's all AC coupled.
So to make a simpler circuit I sketched up this overkill one.
It's a symmetrical set of szlyskai pairs; Bases tied together, which is the input.
The supplies of which are fed from a pair of op amps that give negative feedback to the circuit (all DC coupled), and also bias the circuit.
The idea being that the 2 symmetrical pairs balance the bias current. Would the noise from these being in parallel cut down on the noise?

Then there's a synthetic load, which I included in the circuit so I could ask about the noise.
In Self's book he mentioned that he had concerns about the noise from the synthetic load input going back into the signal chain. But wouldn't that cut down on the noise?
If you connect 2 op amp inputs together wouldn't the noise be the result of the sqrt of the 2 noises combined?

Selling one Mean Well DRP-480-24. Price euro 50 + shipping cost.

Hi, wanted a pair of Lundahl opt for my Elekit, new ones are a bit over my budget. Shipping will be to CA-USA/ India.

I thought you guys might enjoy these. I made them as a gift for a friend who always wants to know how stuff works. 😏
Offset driver TL design done in Hornresp, physical design done in Fusion360. The layers were cut on our 80w laser. Alternating layers of 6mm ply and MDF. After gluing, I quickly ran the belt sander over them to end up with a bit of a steampunk look. Drivers are SB12PFCR-4 and Dayton TD20F-4. I used the foam for stuffing since it has very little weight for its volume. It looks a bit funky- one bit on one side and one bit on the other, but it is as calculated in Hornresp. Any more kills the LF and when I tried less, they sounded boxy.

The acrylic sides do vibrate very slightly at high volume, so I’ll readily admit that they are not perfect - but they do sound very very nice. By far the most expensive cabinets I have ever built!

#translam #tl #transmissionline









Ve

Can someone draw a draft of how this can be done? The Power Supply is intended for use with a Texas TPA 3255

Hey guys ! I was hoping for some help trying to pin down some datasheet with any Inductance equations for the a lamination I purchased. I got it from a pretty shady shop with no data on manufacturer , composition or even part number. I have determined the dimensions do line up with the EI-114 type.

It seems to be some form of silicon steel to the eye , although Si% is hard to determine. I would assume somewhere around 4% as that is the most common for purchasable domestic transformers in our country. They have a thickness of ~0.5mm (calculations show somewhere around 0.496mm).

Ultimately what I'm looking for is an equation that will show what N primary turns is needed to get some L Inductance value in the core. For example, from Robert G. Wolpert's book he found a catalog for his lamination with the equation L = .9283 * 10^-8 * K * U ; where K is the stacking factor and U is permeability of core material.

Thank you for the help !

ok here is a few facts and a few questions around the audiolab 8000 a

---First to notice that units in production till 1992 are equipped with 220V trafos so many of these units with now days 230-240 voltage in Europe will produce almost 43 +43 volts after the capacitors and these few 3-5 volts more per rail will eventually stress the amp and coloration of burned pcb will be there

---Also noticed that either after year 1992 trafos are different so with 230Ac produce almost 40 Volt ( or they simply realized that they are stressing the wrong circuit with the wrong ways.)

---the audio lab 8000S is an sziklai or CFP if you like that means that the double VBE multiplier lays on the drivers .

---Let us forget for a minute the weird bias procedure where a tech is requested to remove covers install probes re install covers and adjust the bias 😱😱😱

---Real problem is that the ventilation designed works only for the outputs and the rest of the amp is tight sealed where in the driver area temperature will increase then the Vbe multiplier will drop the bias according to the temperature ....probably over compensate and reduce the bias more than needed .

so Solution 1 will be to almost over bias the amplifier and expect the VBE multiplier to finally adjust something more reasonable when the pcb are will reach the ""operating'' temperature

Drawbacks will be
--that you still going to stress the pcb and parts around the amp
--will take quite a lot of time for the amp to stabilize a temperature
--And don't know why but i still think that there is still going to be some thermal run away

or Solution 2 drill fins or long ventilation halls above the driver area
---Bias the amp to the manual stated bias
---Defuse all the concentrated heat from inside the box
---Allow the Vbe multiplier to adjust the bias only when amp is stressed

i dont see any drawback here ....



opinions please

kind regards
sakis

Hi Guys
Has anyone tried polar & non polar kaisei caps ?
Curious how they sound, not cheap so wondering if they’re worth trying.

Thanks

Test seas h87 1969, disassembled and centered with Arta/Limp and dats v3, for their age they are very good, we are looking for these mid/tweeters for something fullrange alnico, about the same age, I want to build something omnidirectional only with old speakers, for amplifier on lamps.

motosapien said:

I like the looks of the Schiit Urd transport. It is a bit pricey but uses a rare these days high quality all metal cd drive. Cannot find much discussion here about it though. Does it have glaring flaws or something?

Click to expand...

I just discovered the Urd, with its USB Audio output that can feed a USB DAC. Having designed a number of USB devices and hosts, I am familiar with the USB Audio mode where the destination can control the rate of data from the source, and I wonder if there is any combination of Urd + USB DAC that uses this feature.

With USB Audio, if the source happens to be running a little faster or slower than the destination, a low-bandwidth communications channel on the bus allows the USB Host to reduce or increase the number of audio samples in future buffers to keep the source in sync with the destination. This avoids real-time sample rate conversion, and also avoid complicated PLL systems to match the rate of the DAC to the media. Ideally, the USB DAC would run from a high-quality local sample clock, without any PLL circuits to slave to an external clock.

For this USB Audio feature to work, a USB DAC Device would need to implement this mode. There are three audio modes, I recall, so there's no guarantee that a USB Audio Device DAC would necessarily use the best mode. In addition, the Schiit Urd as USB Host would also need to implement this mode, and in particular would need to slow down the CD transport motor, or speed it up, in order to adjust the rate of audio data flow to match the DAC clock.

Does anyone have any idea whether all of the pieces are place for this to work?

Brian

I have a Sonodyne Uranus FM3000 model. Which is the last Sonodyne model before they stop their business initially from India. This machine was unused for several years and now I want to make it back to working condition. Can any one help me by providing Service manual or Schematics?

Thanks in advance.

Not: I may have posted this message to wrong section. If I have done wrong, Admin please put it in right place.

Hi everyone!

I have this amp (Hertz HCP 1D) burned badly under mainboard....few parts missing/melted - also lost copper tracks.

Does anyone have pictures of this amp under board, good guality so maybe I could re-do those tracks 🙂 Or schematic could be even better!

Thank you!

Also coil at speaker output is burned/melted :/

Great amps I just finished, very clear neutral sound. Optimized for 60hz up but sound great full range too.

Pretty dang quiet, I measure .6mvac at speaker terminals

A nice feature is the inclusion of an XLR input. So if you have a balanced out DAC with 4vrms output you can use it still

Изготовлен мной с минимальным количеством конденсаторов. Я считаю, что именно они негативно влияют на звучание. Устройство состоит из 2 блоков - блока питания и самого корректора.

Hi. Hope to tap on the collective experience of all! Tuts

Hi
I am Sankar from India
I owned a second hand Cyrus 3 after 3 and 4 hours the amplifier stops working and the lights on volume control LED glowing randomly and the input selected buttons also all they Lights leds Are glowing I have to disconnect the power and wait for a day and then after waiting for one day period next day it works by luck if not i have to swich on and off repeatedly by luck it works, what is the problem and how to resolve this, i have some electronic basic knowledge, not mucj as microcontroller coding, i am very much love to hear music in cyrus 3, please reply waiting for your valuable reply
Thank you
Sankar

so I want to replace the polypro cap (250V rated) with a one that's rated 160V. I've seen other caps (electrolytic) in the crossover and those are rated 100V so I guess that's ok. right?

thanks

Found these drivers stashed away for years. Does anyone have data sheets for these? Yes I've tried searching (as much as I am able) but to no avail.

MB Quart MCD 19 Tweeter. 19 mm Titanium dome. Sticker on tweeter say: 95-6464, Made in W. Germany 8 ohm.

Peerless 5 inch, 8 ohm mid-woofer, Made in Denmark. Cast basket, paper cone, rubber surround. Cat. no. 831667.

Any info greatly appreciated.


Regards, Steve

The recent discussions in the threads "Return to Vinyl" and "Contactless Vinyl Playback" has answered many questions, yet some things still remain somewhat of a mystery.
To get to know how something works, sometimes it is useful to try to create a model, a model airplane, or a 3D model or drawing. Suggestions to 'add your own tone arm' and members projects have been encouraging.

Images below are taken from screenshots of a 3D model I created for the listening area discussion. The layout is close to what I would like to have in a turntable, simple, block shaped plinth, with a single speed belt drive. There are other discussions, which I will link here, however, few of them have any 3D illustrations and discussions of design.



Significantly, today, June 7, is the birth anniversary of

1843—Susan Elizabeth Blow, American educator who invented kindergarten

https://www.thoughtco.com/today-in-history-june-calendar-1992503

Click to expand...

I have been using TraxMaker (part of Circuit Maker 2000) for over 20 yrs. I recently moved across to KiCAD and am getting to grips with that for all new boards moving forward

However, I still have a lot of boards on TraxMaker but have a problem that has recently emerged. Everything works ok except the DRL files are corrupted and are complete garbage. Has anyone else found this problem? I am unable to import the Gerber files into KiCAD PCB because although the tracks and board outlines are all ok, it can’t read the DRL file because it’s corrupted.

(I won’t be designing new boards on TraxMaker).

New poster here though I've been a lurker for years. So I apologize in advance for being a bit of a nitwit on some of this. I know enough to know I dont' know enough.

I ran into a very good deal on both KEF Q800DS and R800DS. I've incorporated a pair of them in my surround system as rear surrounds but I'd like to use the other drivers to make non-dipole speakers, similar to the KEF R8 speakers, and just use these as directional speakers vs the diffuse dipoles. I'd use these R8 style speakers as wall mounted not to set on top of speakers. I currently have KEF R300s, R200C, R800DS being used and trying to acquire/build proper "height" speakers for an Auro 3D setup.

However, after some research and testing I've come to find out that the drivers used in these units vary a bit from the LS50 and Q150s in that the MF/LF driver is 8ohm while the tweeter is 4ohm (nominally.) I read a post by the KEF guy (Jack something/ hyphenated name) where he talks about how they wired these dipoles. I can find it if someone is interested.

My question is, before I get to far, will I be able to build a crossover to make these work properly? I was hoping it'd be as simple as building a replica of the xover but it seems after some initial testing that I'm getting some volume reduction on the tweeter (due to the xover expecting 8ohm vs 4ohm?)

I'm very skilled with woodworking/manufacturing and have the proper tools to make quiet nice and sophisticated DIY speakers and crossovers but I very admittedly don't have the necessary knowledge. This project is meant to be an introductory course on my way to build a very nice/expensive pair of DIY towers.

As I'm looking around, and as with many DIY things, I understand it may be easier/cheaper to just buy a pair of on wall surround speakers, (as the required fidelity is very low as well,) but I'd like to give this a try, to a point. I guess I need to know if that point is going to be worth it?

Thanks in advance for the replies. Here's the pics of the drivers from the R800DS and Q800DS.

Im finally doing surgery on my BOSOZ preamp. I have a BOZ preamp that Ive been using for the last two decades that I totally love. I never had much motivation or time to finish my BOSOZ. For the last 6 months Ive got too much time on my hands

I probably built the BOSOZ in 2005 or so and i had some power supply magic smoke when i attempted to bias the circuit. Did some sketchy things back then with the seperate power supply. I finally fixed the power supply last week, so figured Id starting fixing the preamp section. I have a 4 deck 10k DACT attenuator on the output of the circuit which I dont want to change. My question is on P1 and P2 ....which I blue wired a couple of 10k pots....I want to get rid of them and repace the two with fixed resistors
Would 10kohms be the ideal value or?

Also would it be possible to change the bias pot with a fixed resistor? Without biasing this specific circuit? I was hoping that there may be some known value that would work. I want to get rid of this pot as its almost impossible to tweak easily
Thanks (ignore the white wire as this poor BOSOZ has been a storage bin for far toooo long)

Hello everyone, it's a pleasure to be here, a little story 1st then, and then onto my question, which surely will be one of a few over the next few weeks

My listening story is way over 40 years on and off, but my restoration story is really under a year.

So, back in the day, I had a pair of Heybrook HB1's, my mate had Mission 700's, and boy did I love the sound of my HB's...Life came along, work, kids and all that, until 3 years back when I thought I would "relight the fire", and bought a pair of HB1's , cheap amp, turntable etc.... On and off listening, bits of cheaper kit, until I found Tidal and it all came back to me... and thats when the HB1's driver cone surround disintegrated on boxing day 23 ( funnily enough with the Jacksons blame it on the boogie, I sure did blame it on that)..

Oops, new speakers then, what turned out to be nasty ones from Cambridge Audio, went straight back, so...fix the HB's??? And yes I did, well, one of them, the other hasn't as yet given up...nice, very enjoyable, sort of relaxing, I like this hobby.

I was in a Vinyl shop in Inverness, chatting away as you do, guy said to me, you know there is a man close to you who fixes older kit (and sells it also), I made contact with him, saying I was looking for some Ditton 66's, good luck says he, why not try some KEF 104 AB's???

So, I found some, sublime (even on a cheap amp) so, much better amp (Evo 150), Qobuz.... fashioned some stands, lots of reading, suggestion was always update the caps etc...gulp, bought them, delivered, heart in my hands I did the first one, took me an hour, very careful.... reinstalled ..... incredible, did the other (20 minutes).... I love them, and this hobby.

Last weekend, I took a trip to Edinburgh to pick up a pair of Wharfedale W3's, once home I played them very carefully with the old Amp, they sounded OK, they looked dreadful...perfect project.

Ive stripped them down, and both the tweeters and woofers are excellent , but both of the mid range (Super 5's?) have some degradation around the cone surrounds, roughly about 1cm holes in both, so how do I go about fixing these, I cant find anything as easily as I did on the HB's, I don't want to just swap them out....thats my question then, how do I repair these??

I can see Galu makes some reference here to this issue ( https://www.diyaudio.com/community/threads/dont-know-what-to-do.385233/#post-6996826 ), but cant find much else, nor can I see a way to direct contact Galu either (New boy error likely here)... I would appreciate any advice, thanks in advance.

I’m sure there’s a potential to design speakers according to the marketing department’s request. But can we reverse engineering down to the T/S parameter selection of the drive units? For example, assume they request for the closed enclosure bass loading with F3 at 30Hz and Fb (box resonance) at 35Hz. Is it too complicated to find the woofers that could meet that requirement? If not, could anyone advise for the above example, what should the T/S parameters of these woofers look like? Or what information will be additionally required?

This has probably come up before, but a quick search didn't help. When wiring up a kit are there "Best Practices" regarding solid core vs. stranded. Is it advantageous to use 1 type for low level signal vs speaker level vs power?

perrymarshall, I am just now rediscovering your design in this forum. I recall seeing it online a few years ago. Difference for me then to now is that I am dangerously close to retirement and “need” a project. Haven’t built a pair of speakers since my early twenties, and am an electrical engineer and a woodworking enthusiast. You mentioned if you were building again, you would not do the half-circle cutouts on the triangular stands, and that you would go with a greater width for the baffle. What do you think the optimum would be for baffle height and width? And are there any other “tweaks” that you would recommend for someone starting a build of the basic design now based on any newly available speaker components, active electronics, etc. ? Thanks in advance.

I've come across Sonarworks SoundID Reference for Speakers recently, but had to find out that this Speaker/Room adaptation software does not provide filter settings for miniDSP. This is unfortunate as the User Interface and wizzard steering looks very promising and ease of use well beyond other powerful tools.

Sonarworks responded with a "no support planned for miniDSP platforms" kind of message:

... it actually takes a partnership and a joint development effort to implement and proper export/import solution, support it long-term, and have a business model associated with it ...

Click to expand...

So, I also asked miniDSP tech support and their answer is:

... last we know, it was indeed possible to load Sonarworks inside all OpenDRC series ...

Click to expand...

I'm actually using openDRC DI, so my question goes to openDRC users:

How can I or how do you load Sonarworks filter settings into an openDRC DI?

Thanks and Regards,
Winfried

FOUND A SELLER>> I'm looking for an ACA Mini with power supply in working condition in the USA.

Looking for someone that can design parts for me from time to time PAID in EagleCAD 7, I often need a part made, or adjusted and I have not had time to sit down and figure it out for myself, Willing to pay someone that can do it for me. either by the hour or by the part.

Please message me if you can help


ZC

Hi there im new to this forum. Glad to know here is much information for my music hobby's. Im interested to electronics hobby. I hope I can learn from all of you. Thanks!
Alda

Hi All,

Just saying hello from deepest Northants, UK

Looking for some assistance with 3 way (full range) wiring, but i'll get into that later 🙂

Looking forward to being part of the community.

Tim

Step by step: full recap + upgrade with Audio Note Kaisei
caps and Vishay polypropylene capacitors.
P.S. The resistors R88 and R89 -IRC 1 Ohms 1W, generate too much heat , the new resistors are CPF21R0000FKE14 Vishay DALE Metal Film Resistors -1 Ohms 2 W.

​

Living in Denmark working as independent IT consultant. I have a high interest in technic incl. audio.
I especially find it interesting to build audio solution with cheap class-d amplifiers.

. I am a (non practicing) Electronics Engineer .I am here to discuss my interest in audio electronics. I am interested in analog audio systems.

Hi I have a KICKER ZX1000.1 on the bench,
The amp was cycling in protect mode, the red led would illuminate every second.

I found one of the output transistors had zero resistance on all legs so I pulled it and tested it off the board and same result.

The amp now powers up without going into protection.

The transistor is an IRFP264N, there are 4 in total, should I replace all 4?

Thanks in advance

This is a great Sony four-channel reel-to-reel. It needs repair. What I can tell is that many functions are functional, and the motor drives are working, but it definitely needs to be repaired. Otherwise, cosmetically, it is in great shape. Asking $ 250. Only local pick up in Los Angeles, Calabasas area.

I recently acquired a Sony 227ESD CDP from Germany via eBay.

Although the player initially worked it now refuses to track discs most of the time.

I've been pulling my hair out over the last couple of weeks trying to diagnose the problem and tonight after removing and examining the transport carefully I finally found the problem.....and it's not good news. 🙁

The KSS-151A uses a linear motor for the tracking and I've found that the plastic guide rails are cracked/fractured in several places. As the optical pick-up unit tries to slide of this rails it catches on the cracks and and prevents the laser from tracking properly.

In the photos below you can just see the fracture lines.





I wonder what has caused this? Ageing of the plastic? Mechanical damage in transit? The wrong lubricant? Has anyone seen this problem before?

If anyone has a KSS-151A with a dead laser they would let me have/buy for parts I'd be very grateful.

Any experiences here with this tube? Looks like decent triode curves. I am thinking of trying it on a build. As input gain and driver. Any opinions?

I'm listing a TDA1541A S1 Crown that I purchased five years ago from Europe. The chip was NOS from a tube. I have three of these chips and this is just sitting on a shelf as I probably will never use it. Tested in my D3 distinction dac project.

I will ship the chip anywhere in the world, insured for $250 USD. It will be shipped in a hard plastic case inside of a static bag. Also, I will test the chip again before shipment.

There is no warranty nor is there a return (just as their were non for me when I purchased it), however, my standing on this forum for 20 years and my word is what you have.

Thank you for looking,

Regards,

Greg

I’m working on a 6sl7 front end, and with the extremely low current i can’t use the normal 10 M 45 that I would in most cases. B+is around 360 V, with 100k plate resistor. I have a bunch of the 2sk2700 fets that were used in the first tubelab se, can I just use the follower section without the CCS? Any problems I should be aware of?

PCBs and modules for high quality AD797 MC phonostage

I have few more PCbs for this phonostage.This is one of the best DIY phonostage for LOMC designed by Ak member Hypnotoad, also very cheap to build. Here is the thread AD797 Phono Stage Build and Help Desk Thread | Audiokarma Home Audio Stereo Discussion Forums



Phonostage and power supply modules



Phonostage PCB $12
Power supply PCB $8
Shipping $6 by Registered post

Phonostage module including all 4 opamps $100
Power supply module $20
Express shipping $25 by UPS/DHL

Regards
Sachin

Hello!

I am simply here to get involved with speaker design, mainly in headphone work but later loudspeakers for myself.
I am from Ireland have have a good amount of experience in headphone design and acoustic structures, so I think now is the time to make my own from scratch.

Hope all is well for you fellows!

I have a pair of Coral 8CX-50 I bought in a package deal that I will never use so here they are for sale. I hooked both of them up to make sure the woofers and tweeters were working and that is all I've done. One is missing a small bit of rubber covering the tweeter bridge that you could replace if it bothers you. I think $75 plus PayPal fees for the pair and shipping is fair but if you don't, send me an offer.
Thanks for looking,
Marty

I'm struggling to find out what brand and type they are.
The small ones that to can see the blue tops of are the same brand.

Thank you!

A few components, some electricity and a new adventure begins - a journey. How can we describe the fascination?

Ever since I was a child, I've been fascinated by amplifiers - you can turn them or push them, even the "on" pop is somehow part of it, or the switches, the rocker switches of the 70s.


Long story short:
I have never heard a JLH, not even an original Hiraga. Other concepts have. I don't need much power and it's already warm enough anyway, why not make do with 10 or 20 honest watts?

Maybe the attached ideas are interesting - the components are slumbering and gathering dust in my boxes. I originally wanted to use the IRFP044 in the ZEN4, but then it became an Aleph5 and the HEXFETs have been lying unused on the shelf wrapped in aluminum foil for decades.

Now it's about time...

Kind Regards,
HBt.

I would be pleased to receive comments, suggestions and cooperation 🙂.

Well I need a straight answer on something and I’m hoping to get some folks feed back. I have a pair of Coleman Raw DC board - can I supply them both from a single transformer? Maybe this has been explained but I can’t find it so…..thanks for any feedback!

https://audioxpress.com/article/focus-computation-of-bass-reflex-alignments



dave

As above, a pair of Cetron USA made 805 triodes tested here - Login to view embedded media The top caps look to have been re-stuck in the past, bit of a mucky job but they will clean up. I carefully scraped a small area of the gunk on one triode with a scalpel blade. There's also some verdigris on the top caps which again will clean up.

Price £300 the pair prefer to ship withing the UK but will consider shipping overseas. Contact me for postage costs, it depends on whether the buyer wants them insured.

TFL, Andy.

Came across these wooden nails for use with nail guns!
https://www.beck-fastening.com/en/products/fasteners/lignoloc-wooden-nails~pc2387

Very exciting!
Supposedly the nails are filled with a lignin based resin, and when shot into the wood they create a bond with the lignin in the wood that is compareable to a form of welding.



Her is an example where they end up lifting a car with 4 nails in 4 places so a total of 16 wooden nails:
Login to view embedded media
Noticed that it seems this product is 3 years old but I've never heard of it, looks awesome!

Hello all

I had a stuck pot that was causing a lot of crackle, particularly in the right channel. I swapped this out and the left channel is fixed but the right still has a bit of crackle. Have I purchased a dodgy pot or could there be a problem elsewhere, maybe with grounding?

Ta all
Sachin

Going to try and keep this simple, because I think I know the answer,

But my thoughts

Coxial driver 13.5 BC cxn88
Sealed
Just for fun 400hz hp to LF driver
And the mid 2k
In a 1cuft box and 1000w
There's 1mm of movement on the cone
80* coverage is better then all normal size horns ,

But when I put this speaker horizontal
Won't the LF driver hinder that 80* ???

Is there any difference if the BC dcx464 ccd is used on the 18Sound xt1464 horn ?

SOLD OUT*
Four pieces of spare AD1862N chips. These are from Rochester Electronics...possibly the last place on earth to stock genuine new AD1862 chips.
4 Chips + Shipping worldwide (Registered + Tracking) = US$160
PayPal FF please. Thanks.

I have been eyeing this one for a while as shipping from US is very expensive for my location. Would something like this be any good for a decent pair of mains? Does anyone know what type of tweeter this is? If this thing can do well, either hung of 150wrms would be brilliant. The tweeter leads can be separated, and the unit used in an active two-way, which is how I would prefer to use it with DSP

That's another thing that I am getting a bit mixed up with, especially how much power would I need for the tweeter? Would 10w be enough to keep up with the woofer?

Apart from the high power use, how would this coax go with a small tube amp in a different use. I have been looking for a pair of coaxials to use in a battery powered portable with 10w + 10w

https://ds18.com/collections/8-loud...-2-way-midrange-with-tweeter-built-in-275-rms

SOLD
Spare set of Miro PCM63 DAC for sale. i2s inputs on board.
Circuit design and board info available here:
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-209#post-7049224
Look at the info in the thread to see the PSU requirements.
Basically you need +/-5V for digital and +/-5V for analog sections.
The IV op amps shares the +/-5v with the PCM63's analog section.
However, I have chosen to wire the op amp to have their own +/-12V supplies (simply by leaving 4 jumpers on the board empty).
This, to me is essential for the IV to produce better sound quality.

Board fully populated with good quality caps eg. Elna Tonerex with Vishay MKP for the op amps, Nichicon KG with Panasonic smd film for the analog supplies, Unicon polymer caps with Panasonic smd film for the digital supplies, and Samsung ceramic bypasses for the glue logic chips. IV resistor is the milspec Dale 'blue devils', which sounds much better than the Dale brown ones. Parts have been chosen based on my personal experiences with a few boards done to get the best out of this DAC. Lots of parts purchased, stored, listening, my energy and time etc....🤣

uf.l connectors have been installed on the i2s inputs, in case you want to use uf.l cables to connect to your i2s source.

The complete DAC board + shipping worldwide ( registered + tracking) = US$275
As usual i will treat Miro to some coffee.
Paypal FF only please.

I found a pair. Thanks.
I want a pair of Lundahl output transformers. LL1663 SE 50mA if anyone have a pair for sale?

Hi,

I have a pair of the Dayton Audio MK402 speakers. There is a new version, called Dayton Audio MK402X with upgraded crossovers but with the same speakers. I want to upgrade mine. Could anybody make a schematics of this?



How could I find out the values of the coils?

Thank you in advance.

I wish all the best to everybody here !

I am not actually educated in electronics, but I came across this forum and realized that I can learn a lot just from reading topics.
I am particularly interested in Analog Source department as I've been a long time vinyl user.

Regards from Serbia.

I am looking for 2 or 4 of these coils or an alternative with 450 mH

I'm gonna go ahead and open up a potential can of worms.
This question seems to be regurgitated quite often and in my opinion with unsatisfying conclusions in the discussion.

Q: What do power ratings of a driver mean and how do they translate to picking a suitable amplifier?

Let's take a B&C driver for example, let's say a 12" 12NDL76.

It was tested to withstand 400W pink noise at crest factor 2 (6dB) for 2 hours (at this c.f., peak power is 4xRMS)
Now what does this mean? A lot of times I see interpretations that rely on crest factor, sounding something like 'well then it definitely can run 400W music material with c.f. 4 (12dB), because that is less compressed. But not 400W c.f. 1.4 (3dB, sine wave!), that would kill it!'.

However, don't we measure Power RMS here? AKA the driver saw 400W RMS over 2hrs, and not 400W peak power of that pink noise, which would mean only 100W RMS at 6dB c.f.. In the latter case they would have to list 100W in the specs, not 400W. But when we start orienting ourselves on peak power values, then the whole idea of performing 2h tests wouldn't make any sense.

When we talk about RMS power, the crest factor shouldn't matter - RMS is RMS. But then again, going forward with that logic, I can't seem to make 100% sense of the way speaker driver specs are being published and how this relates to the amplifier I'll need to run that driver hard.

Q: And then there is the mystery of amplifier specifications. Does Physics work here?

To me, amplifier power output ratings unfortunately seem to suffer from a comparable lack of logic.
Here again, we find the crest factor being of importance. But why? I understand that a lower crest factor is inherently a more difficult task for an amplifier, but shouldn't that be reflected in an accordingly smaller maximum rated power output?

Let's take the LabGruppen PLM 12K44 for example. You can find the thermal spec sheet online.
On the line under 120V, 30A mains for example says that each of the four channels can deliver 'rated power' of 3000W to a 4Ohm load. At the top of the document it says the measurements are done at 1/8 signal duty. In this case 2817W are being fed into the amp, about half is dissipated into heat, leaving 1502W available for all four channels. Generously assuming 100% of that goes into the speakers, that is 375W/ch. And that must be RMS power! And if we want to scale that up to 1/1 signal duty we indeed obtain 8x375W=3000W. So far so good.

But can we actually get that 1/1 signal duty? For example I would like to power 4x 4Ohm dual 18" 2200W continuous on one of each channel. This demand seems to collide with the statement of the 1/8 signal duty being the most extreme sustained normal operation as stated in the spec sheet? And how in the world would the amp even deliver the rated RMS output at 3000W/ch when the input at 1/8 signal duty is already at 24A!

When we assume a crest factor of 12dB for the pink pseudo noise, then the peak power in this case is about 16xRMS, which is 16x375W=6000W. it seems to me that the rated power in reality is somewhere in between the RMS power and peak power of the test signal, 375W < 3000W < 6000W. It also seems that it is connected to the crest factor of the test signal. And I would expect the rated power therefore to be reduced for lower c.f..
The power spec sheet indeed reveals that the 3000W/ch refers to a burst power (1 kHz, 25 ms burst power @ 150 BPM, 12 dB Crest factor), so it is indeed more of a peak power rating rather than RMS. So 1/8 signal duty is somewhat misleading as it suggests, 1/1 is possible.

Other reputable pro amplifier manufacturers seem to benchmark their rated power output by burst power capability as well.

Speaker driver and Amp together

To stick with this example, with my dual 18" rated at 2200W, 4Ohm, I really would think the 12K44 would be a great match with its 3000W/ch at 4Ohm. But following real RMS values, my 2200W sub would not be properly powered. And this goes against the typical advice which goes like 'get an amp that has 1.5x rated power of the drivers RMS value'. So how does this fit advice in here?

Anyway, looking forward to your thoughts on this.

Does what seems to be an amazingly flat output between 100hz and 2kz when installed in a 1 cubic foot sealed enclosure nearly as well as it looks on paper?


Member @conanski relayed is opinion of the similar 8" using the wizzer design as "very natural sounding" which is exactly what I desire.

I need a large quantity of sound without excessive amplitude or any sense of strain.

This is to echo if I dare the nature of the acoustic player grand piano that it accompanies. It's the most fantastic on-demand auditory experience of my life.

Cross-link to: https://www.diyaudio.com/community/threads/accompaniment-for-player-piano.416957/#post-7776819 made because the nature of my situation does not categorize well among the choice of forums.

Hello

I have 20 x BRAND NEW Eminence Alpha 15A Woofers

https://www.parts-express.com/Emine...H95WFHPbnNfu877k95R5Xg2HdD8EHh4YaAn4vEALw_wcB

I will sell these at $68 dollars each plus freight. These are brand new in the original cartons

This price is for 8 or more. Less than 8 - $75 dollars each

Thanks

Mark

Really. It's 2024 and nobody is selling a simple line/speaker level module with mains level connection and amp/component main power socket?

I have short-term need for one and thought I'd have it in a couple days.

I've found a good project description but the required NJM2072 IC alone is going to cost at least $15 by the time it is shipped.

For that reason it looks like this board is my best value to begin the project. Anyone familiar with it?

I have the pioneer PL-a500s which requires 100V AC. Would making the conversion be as simple as swapping out the 500s transformer with a 110v transformer from a US market PL530? The turntables are identical inallother regards...curious if I would need to swap out the power board as well...thanks. Jim.

Antek is currently out of stock on this transformer and I’m building an amp for a member.

Anyone have one they would sell? Willing to pay full price or a bit more.

Hi All,

Just wondering what system owners are using for power protection / conditioners? Particularly when running a PA off a generators outdoors. After a small incident with one of my amps a few weeks back I dont particularly want the stress and hassle of that happening again (rewiring a system that tested fine the day before about 10 mins before the music was meant to start).
It looks like there are many options ranging from <100 to 5 figures. Whatever I use I guess it needs to be fairly beefy, possibly one per amp with each one pushing between 3500 and 5000rms.

Thanks in advance

Does anyone know audio dac part number (likely TI or AD) that as title says, has constant current sources organized in Menorah way.
Designed 20-30 years ago, probably still in production.

I have 2 125W impedance matching transformers. Bought in 1972 for a project I'll never finish. Primary: 14000, 10000, 8000, 6000, 5000, 3000. Secondary: 500, 200, 50, 16, 8, 5, 3, 1.5. Dimensions: 5.5" high, 5.25" diameter, 14 pounds each. Prefer to sell as a pair. $300 for both +shipping from SW Michigan.

Hi, I am having trouble finding how thick i would need of rockwool safe and sound in order to absorb fairly evenly down to 30 hz. This would be broad band absorber to absorb from 20 kHz down to 30 or 40 hz.

Thanks,
Logan D

Any experienced digital experts here?

Someone in some threads said that Multiplexer ICs and CPLDs can cause jitter, so you should put a reclock behind them.
I'm sure experienced engineers know this well.
Is this actually true for 74lv157 or CPLD?

If the jitter for each line is not random, but the same, and short enough,
I think it can be adjusted with series resistors. What do you think?

Of course, jitter will have different effects on different DACs, and in a DAC like the AKM that is jitter tolerant, it may be audibly or measurably meaningless.

Hi all.

I am looking for the service manual for a Sony receiver, STR-V2 (mid 70s). Nothing anywhere, including Hifi Engine--apart from a document desrcribing the whole series' tuner alignment etc., without overall schematics. This document does mention that the STR-V2 is an outlier in the STR-Vx lineup, hence my problem!

It was working fine until yesterday, when I moved it to my basement shop. Now it instantly blows fuses in one of the AC low voltage legs (i.e. after transformer). Is it a failed capacitor (failed closed circuit)? A failed voltage regulator transistor (if any)? Problem is I have no schematics to suggest a culprit...

As I wrote, service manuals for other receivers in the same series are available, but the STR-V2 is different from the others. Tone controls are in power amplifier feedback loop, it has no preamplifier stage! I know it was almost bottom-of-the-line originally, but I like its sound in my 'retro' setup. Very 70s, a bit of emphasis on bass.

Please help me... Cheers!

--Christian

I am about to receive a Sunfire Subwoofer Signature 12” version in unknown working condition (the red led at least lights up) to replace my smaller single 10”. I plan on replacing the shitty power supply capacitors immediately, I ask you is there anyway else I should beef up? Probably put in fresh +-12v or whatever is in there for regulators. Will I feel that 2700w in my gut vs the 500w? How the hell do they squeeze out another 2200w from that downconverter design? Is it more likely to fail vs its younger siblings?

As I am slimming out my DIY projects backlog due to the lack of time building all the stuff lying around I will post many undone projects and PCBs I collected over time.

Planned for another project that was never finished after I built my VFET I am selling my pair of Tokens which were bought back then from a reliable source published on these forums. I have no clue who it was. Paid 150$ for the pair.

Asking 120€ + shipping + PP fees. Adding a set of insulators for the holes and Keratherm (leftover from VFET build).

Hey everyone.

I'm trying to restock my heat shrink tubing and I'm wondering where people get their heat shrink from in Europe. I'm looking at farnell and mouser, but any options outside of white, black and red seem to be much, much more expensive than their more common counter part. Am I looking in the wrong place or should I expect to pay anywhere from 3x to 10x the amount on blue/yellow coloured heat shrink?

Thanks in advance for any input 🙂

New poster here though I've been a lurker for yearks.

I ran into a very good deal on both KEF Q800DS and R800DS. I've incorporated some of them in my surround system but I'd like to use the other drivers to make non-dipole speakers, similar to the KEF R8 speakers.

However, after some research I've come to find out that the drivers used in these units vary a bit from the LS50 and Q150s in that the MF/LF driver is 8ohm while the tweeter is 4ohm.

Will I be able to build a crossover to make these work properly? I'd be trying to get 4ohm (nominal) tweeters to work with 8ohm woofers.

Hi there, very much a DIYer, I create lots of different Arduino-type projects, both for myself and acquaintances.

Here are a couple of projects I've incorporated audio into....

1. I call it the HBTY box, and it is installed in a sports bar/restaurant I do all the technical; stuff for. It has Line-In (from the Sky receivers), AUX In (for anything else), Bluetooth connectivity, USB stick (for playing mp3 files, and a special button for playing the owner's preferred "Happy Birthday to You" song from a MicroSD card when someone celebrates with a cake etc.

All controlled by a PT2134 4 into 1 audio processor module, under the watchful eye of an Arduino Nano. Source changes are all faded in and out, so it's a "proper job".


2. In the same venue, the house speaker system is used for the multiple screen sports, but they have recently installed a jukebox. It's a PITA for the bar staff to have to turn down the house system when they allow the jukebox to be played (some sports, especially football matches, take priority). I've built a detection box that can be fed from an unused speaker outlet on the jukebox, which will cause the house sound system to fade to zero as soon as it "hears" the jukebox playing, and fades it up again after a programmable silence period (inter-track delay). Although I should have used logarithmic digital potentiometer ICs, we can get away with linear, because the house system is either fully-on, or fully-off. It being a linear fade is noticeable, but not badly so...

I could go on some more, but that's enough of me boring you all...

I have a large quantity of the guitar amp specific open frame Push Pull OPT's seen here, still in their original 8 pack boxes from 1990. These are the same transformers seen in my "under 100 WPC" tube amp experiments dating back to the early 2000's. Originally made by Schumaker Electric for ADA Signal Processors for guitar amp duty, they are rated for "80 VA from 82 Hz to 5000 Hz 6600 ohms to 0-4-8-16." They work well at 3300 ohms to 0-2-4-8, which is how I usually run them.

It is pretty hard to make an OPT that only goes to 5KHz, so I have tested them in HiFi applications. They were used in my 300Beast, a zero feedback push pull amp that used 300B tubes. Here they went from 25 Hz to 18.5 KHz at 10 watts with some saturation seen at 28 watts below 30 Hz. They do better when driven with low impedance sweep tubes, and slightly worse in an SPP amp with EL84's that really want an 8000 ohm load. They are a standard size as I have found some end bells from other transformers, that fit.

Stuffing over 100 watts through one for guitar use seems OK, but don't play bass through one beyond about 35 watts. I will sell small quantities to interested builders. for $30 each. They weigh a little over 5 pounds each so shipping isn't cheap and international shipping is probably not viable. Up to 4 transformers will go into a medium flat rate box for delivery in the US for $19

For those that shop hamfests, I have been selling these at the Dayton Hamfest for years, but at a higher price. I will be there again this year, so if you want these at the Hamfest, mention this forum to get them at $30.

Completed PCB only. Just add power through the DC jack and it works. A laptop power supply works fine. Used for a while to power TV speakers. The TPA-3116 was highly regarded for sound quality and it suited my needs fine, but I purchased an amp with trigger capability to pair with my DAC.

$20 shipped. Payment by PayPal. SOLD

Folks,
I am working on my Arcam Delta 290 and I already found so much valuable information here that I decided to join the forum. I'm 48 years old and and able to use a soldering station and a multimeter, but that's about it. Just enough to keep quite a lot of vintage gear up and running 🙂.

I wonder if someone tried to make from a chip amplifier a current amplifier design (inspired by Esa Merilainens - current drive info Website) if that is technically possible.

Maybe it is easier to do that with a chip amp or it is not possible at all. At hand I have some amplifier with TDA7266 soon - which has two times seven watts.

Would like to hear some feedback on this, maybe a modification of an existing mini-amplifier from the far east which could be found easily on ebay.

It would be enough for me to have two times five watts, just in order to hear such an amplifier together with classical fullrange loudspeakers with double cones.

I am only interested in pure current drive, no voltage drive in the bass. As I always build my loudspeakers by myself and never use commercial ones.

Dragan from germany