Used but in good cosmetic condition and working order. Selling because in the end it provides more gain than I need with my ACA. Comes with power supply.

Send me an offer and depending on how far I'm shipping ill consider splitting shipping costs.

Looking for at least $95, before including shipping costs.

Hi,

Just completed the N Channel version of the VFet, and am wondering if it will be safe to use w ESL-57 and its somewhat challenging impedance curve?

Thanks!

P

Hi there I need some professional help with an amp board that I bought from Ebay…
Digital TDA8932 Amplifier Board 2x 15w
Digital TDA8932 Amplifier Board 15W/30W/35W Mono Amplifier Module Low Power NEW | eBay



information from the site says ….” Speaker Interface: 2.0mm pitch 2PIN”. So I tried a Molex connector PH2.0 2-Pin (spacing 2.0mm) . It doen’t fit and the seller wasn`’t very helpful. Is anybody familiar with this particular module? I need to find the proper cable/connections. Obliged for any help

Hello all,

I have a Vox AC4C1-12 amp to which I'd like to add an effects loop, and I'd appreciate some advice on how I integrate the two.

I have the ValveWizard effects loop PCB. I couldn't find a decent schematic for the amp, so I drew one out based on a rather blurry image from TDPRI and my own inspection of my amp. The only differences are the power supply (TDPRI schematic is incorrect) and the tone stack configuration (which I _think_ I have right.)

The Valve Wizard effects loop is here:



My questions:

1. Do I insert the effects loop into the amp circuit at C16, i.e. remove C16, and insert the loop in its place, and move that cap to C1 in the loop circuit, so it still acts as the coupling cap?
2. I don't think I need the R9/R10/R11 network in the effects loop, as the output of the loop is going into the master volume. Is that correct?
3. I'm planning to use the B+2 tap on the power supply to drive the loop. I measured that at about 280V - I think I need Rp in the loop to be 10k, and Cp 47uF, based on an example configuration from the valve wizrds site with a similar B+. Is that right?
4. I don't know what vlaues to use for R1 and R2 in the effects loop. How would I work that out?

Thanks in advance.

Jon

I'm planning on adding a Muses remote control volume module to my SSE and I was told I need to implement a muting relay. As a beginner I'm looking for some advice on the best way to do this.

This is the module:
VCU | academyaudio

And this is the power supply I got for it, which I plan to install in parallel with the main power transformer:
https://www.mouser.com/ProductDetail/MEAN-WELL/PD-2512?qs=V9a8iPeg90zL57YT5CaFMw==

Are there ready-made muting relays I can buy and if so where do they do in the signal path? Or are they easy to DIY?

The manual for the 3e Audio TPA3255-2CH-260W says that the input connectors are JST2.54 but I cannot find them on Mouser.

Does anyone know of a compatible connector from Mouser?

Pretty small requirements. I’d like to DIY a “clean side power” for an Allo Digione Signature player. There are several options for kits on eBay and Alispress, I’m not opposed to that route - if someone can recommend one. Or a design. Thanks!

DigiOne Signature Player SPDIF Out

They also have two power supplies

Nirvana $60
Nirvana SMPS

And Shanti $160
Shanti Dual Linear Ultra Low Noise PSU

anybody tried any decent sounding r2r diy pcb dac from aliexpress?

lazy to make from ground up and not expensive since I might as well get denafribs.

Thanks

Anthony

Ok, I admit for free you cant complain, but it seems various digital streams are all over the map regarding EQ, level and maybe even compression FAIK...

Seems someone got the idea "we can process this stuff any way we want and as long as it sounds better over someone's Amazon Echo, they'll land on us over that other station"

Why? Advertising revenue? Are people really that lazy that they cant adjust the sound to taste on their own device - so the station has to do that for them?

I believe my beloved Jazz Groove boosts the bass. Damn them! Other streams like our local KNKX and international "Mother Earth" do not. A stream like "Smooth Jazz Boston" is modulated so strong it knocks me out of my chair when I pick that station.

All the CD ripped music on my server is more quiet than any of the internet streams...

I made an interesting observation with the CDM-1 transport in my Philips based CD-player. I built in a LED connected to the EFAB output of the SAA7210 error correction chip. This output indicates for the SAA7220B/P chip that there is an uncorrectable error in the decoding process, and interpolation will be needed.
The LED is dark on most CDs. It sometimes flashes, not very frequently. But when I play a burnt CD (written on PC) it usually flashes like crazy. If the player is willing to recognize it at all. This CDM-1 does not accept 80 min writable CDs that are common nowadays. I have a more than 20 years old 74 min CD-R, and here comes the strange thing:
At first play the LED did not blink at all. It sometimes blinked only around the end of the CD. But at the second play it blinked very frequently.
After several eject/insert I found that either it has very few errors during one play, or it has many at another play.
My theory is that this might be due to mechanical tolerances in the transport. Perhaps sometimes the CD is better centered, sometimes not.
Interesting, isn't it?

I know there is always a bigger fish in the Sea.

It is always interesting to see and discover new topology
and methods for lower distortion.

Its not for heated discussion.
Maybe a reason for self honesty.
When is Enough, Enough ? As far as actual needed distortion?
Assuming the actual original source of the music has higher distortion.
And even very well built speakers have higher distortion.

.001 Distortion a reasonable number to say.. it is good enough?
Understanding of course seeing a better number when designing
is exciting and something to be proud of.
But what is the threshold between the number game, and what
is actually realistically needed.

Anyways, playing around with somewhat typical Class AB amplifier.
This is a design of mine below.
I just found using common high quality transistors.
Using Feedback current sources.
Then Basically keeping the second gain stage simple eliminates rail stick.
And Using a basic current mirror and boosting up the LTP current higher
than usual. Around 6ma
Seems to hold up rather well for distortion.

R3 and C2 seem to be the real magic,
this network seems to make the
amplifier rather stable, and allows C7 to remain rather low. Which seems
to defy a majority of possible THD at High Frequency.

.001 % Distortion @ 1 kHz
.006 % Distortion @ 20 kHz

It all started when I started researching about Current Feedback Amplifier
I found this
http://hifisonix.com/wordpress/wp-content/uploads/2017/10/CFA-Front-End.pdf
Before trying to make a full blown Class AB 100W CFA amplifier with Quasi Complimentary FET output.
I made my mind to try to make a Line Level Preamp with CFA input stage with Class A Operation.
Main purpose for me is to learn solid state Amplifier design, I am bored with OP-AMP at this point of time.


Design goals[More like Wish list]:-
*10Vpp Swing without Clipping with Dual 18V supply.
*Complete Class A Operation
*Zero Global Negative Feedback [Local Compensation is necessary]
*Harmonic Profile Shall be Dominated by H2
*H3 shall be close to H2 to add necessary psycho acoustic feel of detail.
*Anything higher than H4 shall be below -120db [As H5 and Higher are responsible for listening fatigue]
*Higher order than H2 shall descent monotonically and H2 increases with increase in Frequency
*Close to 200V/us Slew rate
*Higher than 400Khz bandwidth

Use Cases:
*Line Pre Amplifier
*Headphone Amplifier for Inefficient Planer Headphone



I hope all of you will help me in my journey to make some Solid state amp

🙂

Hi everyone, I have a valve guitar amp ( 5E5A schematic) that I have been using since 2005, it has recently had all its electrolytic caps replaced, it has a strange oscillation when I turn up either volume knob, it's really faint, untill I plug a guitar lead in then it's a loud noise, its a fast oscillation sounds like a cat purring, was wondering if anyone has come across this before?

I've been thinking about releasing this idea into the wild to see what happens for quite some time now. I tried to get away from the ring oscillator method of spacing the phases, but haven't come up with anything that works comparatively well let alone elegantly.

There are some known problems.

Current sharing in the real world. In spice everything is intrinsically matched, so this problem goes missing there, although purposefully drifting various values has some interesting effects. For one thing there usually has to be at least the minutest obvious difference between phase legs or all of them tend to stay marching along together as if it were one big parallel inverting leg and complete waste of redundant circuitry.

The funny diode clamp at the comparator input is responsible for the "carrier-less" frequency locking. However, there is an irritating limitations with it that is kind of hard to explain because I don't even fully understand how it works when it does. But if you play with this thing long enough you soon notice that the opposed pair of coupled trapezoids coming off the capacitively loaded clamp end up getting compared against the long ends instead of the short ends. The result it that instead of slopes that run linear all the way up to 0/100 of duty cycle, they come apart and the phases let go of each other as the whole oscillator plan blows up, until the input signal drops down to the point where comparator inputs cross again at regular intervals. Whoever comes up with a way to get something like this to run all the way up to 100% duty cycle while keeping all the legs locked together and balanced, gets the prize.

Oh yeah, and in reality you need a handful of isolated gate drive supplies. 🙂

I have built a single phase version of this with a nifty little resonant gate supply and regular silicon FET output. If you take the clamp stuff away it basically turns into a Putzeys amplifier. Even one phase gets to be a lot of tiny transformer windings. For the pulse transformer I ripped the base drive core out of a bunch of old CFLs. For the comparator I used a AD790. I tried a real build with LT1711 on a ground plane board and it oscillated to beat the band. I mean that thing would not stop talking to itself. I might have been able to tame it but went another way. I doubted it would be better than the 790 in this application anyway.

If someone did this already, especially if simpler or better, let me know. EPC models are big and clunky. To run this you'll need them EPC Device Models

Hello,
Anyone interested in CNC cut flat packs in MDF or Baltic Birch (lumber yard) and shipped via USPS priority?

We can offer discounts on group buys, and I will ship directly to each individual via USPS priority flat boxes from the KC metro area.

Let me know which speaker kit you are interested in.

Unable to source a preamp chassis that I liked, I decided to design and fabricate my own.

Attached are photos of a preamp build using a Broskie Aikido™ line stage, Erhard Audio phono and power supply boards, and an inexpensive relay-switched input PCB.

The PCBs are mounted on a sub-plate that can be raised with stand-offs, which allows for through hole and point-to-point builds.

can somone help me with a kenwood5700.. when power is pressed the outputs on both sides will get very hot until the powersupply fuses will blow,, what mite be the cause ??... the amp has no sound

I recently picked up these powered BT speakers from Amazon, model R28BTUS. They sport a 1” tweeter and 4” woofer. Didn’t need them, but for $25 what was I to do? Crossover is a 2.2uF cap on the tweeter. Drivers wired in series. They aren’t too bad with the ports stuffed, but they very likely can be improved.

The Overnight Sensations using the HIVI T20-8 and B4N design appears to be a very good fit to the unit’s .18cf (5.2L) cabinet. The OD of the B4N frame is .1” larger than the existing, might be able to sand out the difference. The hole for the tweeter will need a bit of enlargement, but that should be easy. Even the odd port looks pretty close to what is needed. Driver costs would be $23 per side, about as low as can be expected. I have good stash of crossover components, so I’m not that concerned about crossover cost.

Are there any other 2 way designs out there that use similarly sized (or somewhat smaller) drivers in about a 5L box that I should look at? Is there a full range driver that might fit with no modifications? The drivers can’t be surface mounted, the grill is flush to the front baffle and there would be no room.

Can anyone share a simple C script to generate a triangle wave in I2S format?

Ideally, would like the flexibility to adjust sample-rate, bit-depth, and mono/stereo.

Or downloadable I2S sample data files containing music or other audio?

This is for testing a device that has I2S input.

thx!

...Well, this thread will be how I build mine. 🙂

Nothing out of the ordinary, Peter Daniel boards, single transformer, Tech-DIY transistors and other bits, HiFi2000 chassis.

I have collected all the pieces and finally today the chassis arrived from Italy! I am ready to start!




Here is the obligatory "armory" photo. Only one of the amp channels shown.


The rear panel. I thought I ordered an Inlet Module with a switch, but I didn't read the datasheet well enough, and it has a neon light power indicator instead. Oh well. Luckily I have a couple of nice bat-handeled switches, I will use one here. The Jacks and RCAs are also from my box, I think they are Vampire.


Here are the contents of the Tech-DIY F5 kits, the Peter Daniel's boards, and a couple of silpads. I also have micas and grease, I will most likely use those.


The PSU components. Vishay rectifier blocks, Peter Daniel PSU board, resistors, 33,000uf capacitors, CL-60 thermistors, and a big-honkin' 600VA transformer.

When I was determining the transformer size necessary I must have had a brain-sneeze, I must have only thought of one secondary! 😀 Oh well, it was only $20 more than the 'proper' (400VA) size. The 4-pin caps will work on the board with just a bit of modification.


If you were wondering, the Peter Daniel boards are very small. Also very nice!

That's it for now, I will post more photos as I progress.

Hi,


anybody can tell me if this protection cage works as shield ( faraday cage ) like a standard tube shield?


Tube-Town Store - Tube Protection Cage - Chrome


Thanks.

Self explanatory. Tell me how tight it sounds compared to ported and sealed subwoofers. I hate boomy subwoofers.

My unit took a dice, and I'm looking for a good working or a parts unit.

Thank you.

Hi!

A am about to make a compact project of PD 10". As I understad the centers of cones should be as close as possibe, I need to maximally awoyd phase issues, as I want them to be crossed at 4k

In the middle a CD, something like a line array but with 90x50 coverage

Something like this
Vi10P loudspeaker from our V-Series | d&b audiotechnik

Selling this nice little passive pre. Beautifully made.

Tisbury Audio - Mini Passive Preamplifier

Has some nice features over and above the obvious volume and input selection, you can alter the levels to the 2nd set of outputs via some dip switches underneath.

Will add photos soon.

£85

Hi all,

I’m after recommendations on diy headphone amplifiers for a nice old pair of Sony headphones I’ve unearthed that seem to be very low impedance, at 14 ohms.

I have a nice case, in the size and style of a quad 405/34 stack it will sit on, some nice neutrik socketry, a 20va 18-0-18 transformer and the bits for a power supply.

I have read around the topic and have been convinced that class A is the way forward at these power levels.

The headphones themselves are rated at 1000mW, which at 14 ohms and 102dB/mW sensitivity would be deafeningly loud. Never the less I have calculated this to be about 10v pk-pk and 300mA output is needed ( to allow some margin).

I would be grateful for suggestions as to designs, so far I am liking the idea of knocking the three transistor amplifier on this forum together but would be interested in more powerful projects to build and try to compare.

48v 300w (6.2amps) smps.

Needs a 5v sense feed to make it work. I used the innards of a mobile phone charger.

Fan removed but included
£30

I've been using Kenwood KD series decks for over 15 years. I decided to change all the electros on the first deck that I thought was the problem for non-functioning - it wasn't and now the second deck has ceased to function.

Both the bearing systems are fine as are both the TX since the power reaches the PCBs.

I will now have to do continuity checks on both and I do have a site that bought up a lot of Kenwood's KD components but if I cannot fix the problems does anyone know an experienced repairer who can help.

I live in France, so I need at least an EU source that can help - thanks in advance.

Hi! I'm new to audio design, but decided to replicate a high-pass filter (Monacor DNH-185) to learn a bit.
I have a signal/function generator (UTG900E) and an oscilloscope (TDS1012B), but don't know how to go about using them to test which frequencies the filter is attenuating and passing.
Any help would be appreciated 🙂

IT IS ACTUALLY A NAJDA DSP 1.2, i was mistaken and now I can't edit the thread's title anymore.

€250,00 + shipping. Paypal accepted.

https://www.diyaudio.com/forums/attachment.php?attachmentid=978119&stc=1&d=1629988160

Hello everybody.
I repair my luxman KIT A501 and share with everyone.



the old pcb is retire becauuse heat and brake,So I made the new one to change it.



It seems good



after I set up parts,I compair with schematic that found something need set in back side.






I use 2SK170 replace to K150 TWIN JFET




All parts done!!







clean up after finish

I am building a 2 way with a Lavoce 12 WAN123.00 woofer. I am considering a ebs3 alignment. This will lower the f3 from 64hz to 50hz. I am wondering what other peoples experiences have been with a similar situation. I guess that I will have to pull the 3db down above this shelf like it is part of the baffle step. I would like to be able to use this without adding a sub to make it sound okay.

Thoughts?

Hi all !

anyone tell me about wrong in this.

Hi there,

I'm in the process of sorting out all the parts to make a class D plate amplifier.

I'm looking into buying a DSP board so that I can bi-amp rather than using a passive crossover.

I've seen a few options around-

-MiniDSP
-Dayton audio
-Sure electronics

The miniDSP option is about €100, which is a bit pricey as that's about the same as I will be spending on amplifier modules. Then there's a massive gap down to the Dayton and sure boards at about €20-30.


Does anyone know about the relative strengths of these products? It's there a significant difference in the quality of the signal coming from a MiniDSP unit?

And most importantly, does anyone know of any OEM manufacturers who make reasonably priced boards?


Thanks
Peter

I have a 9th generation Pioneer Plasma and if I use the Optical SPDIF out, to any DAC the resulting analogue signal is very low.
If listening to music content it fills my room but, a little more, if watching a concert for example would be great.

When I was fixing TV's for a living, the Digital out always, no matter what Manufacturer, seemed low to me.

I was thinking of using a cheap DAC chip, using an OP Amp to raise the analogue level to say a good 2V rms and then A to D-ing the signal using a circuit similar to what must be available at the O/P of the average Minidisc unit.

Thoughts and any other possible solutions greatfully received.

P.

Anyone have a schematic for the amp i an REL T-3 subwoofer?

My T-3 is blowing fuses. I'm pretty sure the output transistors are shorted. The appear that way when measure in the circuit. I'll pull them today and retest.

In tracing the circuit, it does not appear that there is any voltage regulation for the output transistors. Current flows from the transformer to the PS caps and then to the transistors.



I can't find any VR ICs on the board, though there is one op-amp that could be in a part of a VR circuit.



Is it comment for outputs to be driven from an unregulated source?

Finally, assuming the transistors are bad and a replace all 4 (2 NPN, 2 PNP), are there any guidelines for setting the idle current if I don't have a schematic or manual? Should I just leave it as is in that case?


thanks,


James

Hi friends,

I've got my LM3886 stereo system running now for a test and I re-checked the Overture Design Guide spreadsheet after double-checking the supply voltages.

I'm not sure if I should be worried about the supply voltage being +- 38.5V, which leaves 3.5V headroom. Should I be going for a smaller output voltage on the secondaries on the transformer (currently 25V)?

It also seems to think that the heatsink is going to cause me trouble. I've felt the heatsink and it feels lukewarm after 30 minutes of listening. Does this mean the design doc is wrong or I am not outputting 100W ?

I've filled in my values in the spreadsheet and attached the screenshot below.


EDIT: I've got thermal paste on one chip (the other will be done in the next few days), and no insulation washers. I've got the TF package, the one without the metal tab on the body.

Hi there folks I recently bought these old speakers ,they seem to be coaxial speakers .I have spent 3 days on the internet trying to find out what brand of speaker they are without any luck so i can repair the high frequency drivers in them .The high frequency drivers are very small compression drivers with 25mm phenolic diaphragms ..the person i bought them from says they were built around 1965ish..if you can identify them please let me know so i can save these speakers...thanks in advance folks
Ill add the photos as soon as i can work out how to upload them here

Building a Paradise Phono and looking for matched sets or lots of BC327 and BC337 transistors. Only interested in the 40 type. Thanks.

SOLD / FOUND

Evening all,

I've been embarking on more elaborate power supply designs, while going through Thomas Mayer's blog bit by bit. I'm wanting to include in my next build a choke input filament supply such as these examples, from his blog:










So I'm shopping up the components that aren't just on the shelf, and that means just the high current chokes... I won't be using 220, and it will be 5v from the transformer to 2.5v filaments @3amps for two 45 tubes.

The questions I have are:
1. What is the motivation to use a high-quality choke in this position, eg a $150 Lundahl? Why would I not use an $8 toroidal from mouser with the same inductance and current ratings? Is wire gauge important? Why wouldn't we all just go out back to that dead washing machine in our yards, pull the motor and unravel the wire, fetch a nice stick from the woods and wrap ourselves up the medieval clay-pot battery-accessory of an inductor that we all can have for free?

2. Will precise inductance matter much at all in this position? As long as DCR is right, am I correct that I can use a wide range - and would it be correct that I can go ahead and stick to the low end of that range, to minimize size without impacting the function? Say, 1 to 10 mHy?

Thank you in advance for any information. Links are quality input in my book.

The balanced class A circuit in his book is giving me issues. I replicated it in LT Spice and it flat out doesn't work. Can someone please take a look and advise?

I have a rare 1932 triode in which the filament has gone to a high resistance, definitely not open circuit. I want to try re-soldering the pins to see if that will fix it. I've never tried that before and I'm looking for tips and advice.

Thx!

Hello every one, I would consider this my second major solid state amplifier project, but with this one it will be like rebuilding an entirely new amplifier, so I am making an attempt to make the best one I can from what I've salvaged from this one and whatever else I can find in my junk piles.

The amplifier is made by Sears (go figures, considering there is no info what so ever about it). It produces 100 watts into 8 ohms and consider how cheaply made it is, it sounds really good and is a well designed amplifier. I even took the time out to draw up a schematic, which can be used for the convenience and personal use of others.

I have many ideas in mind of how to modify the circuit for improvements, but only understand the basics, so I am looking for ideas of what would make this circuit better, more current capable and efficient.

I have made a few posts on the Class "A" Hybrid Amplifier thread but have not had much help there since this is a class "AB" amplifier, that I indeed want to turn into a Hybrid of some sort, mainly to get rid of the obsolete chip fet at the input stage of the amplifier, so I am more than willing to be walked through the modifying process, as I now have all SUMMER!!! 😀

Here is the original schematic that I drew up, if there are any reasons why what I drew up may not work please let me know! I will correct it as necessary. 🙄

Are these AS194 AS394 true to LM194 LM394 ?
Matched NPN transistor pair
Caracteristics look the same, price is reasonable, this looks too good to be true.
How come they are unknown at Octopart.
What do you think: True or clever fakes ?

Hello to all

I heard that the OEM op-amps of the Pioneer PD93 are not really good and the people replace them. It is true?? What is the difference please?? I need education about op-amps please

Thanks and best regards

I'm offering a set of (1) GC #9243 standard 7 pin and (1) GC #9244 standard 9 pin tube extenders, each labeled "TV tuner socket adaptor." Both are about 2 3/8 inches high. Other than a bit of tarnish on some socket pins and test terminals, these are in nice shape and are tested & working.

$28 for both, free First Class USA shipping included. PayPal only.

I'm looking to renew my Yamaha CA-610MKII. I've had it since 1996.
It is from 1977 I think and is all original and works.
Looking at the Schematic, none of the transistors are available unless you go on ebay. I don't have a problem replacing capacitors as they are available.

I found this website that someone named S.Kinder renewed one but left out cross-reference parts he used!

Vintage Hi-Fi Audio Restorations: S.Kinder's Yamaha CA-610 MKII Integrated Amplifier Restoration

I like what he did and there are a few transistors in the pics and reading that show what he used and are available from mouser/digikey.

So I made a list of part numbers and the substitutes that I think will work. Took me all day!

I'm asking for help if anyone could verify my selections are good and if not, please let me know of alternatives.

I really want get this unit a little more current as far as parts.
For the cost of the replacement semi's, I think it's worth it.

Please let me know, any help would be good...

Thanks all

I'm a casual observer of valves on eBay, just noticed this £1500 (2000 USD) auction. Maybe I don't have the nose for a bargain but just seems like a load of TV/radio valves. Could not see any of the crazy price audio things. Well I suppose it's £1 per valve. So not bad value. I just surprised someone would pay so much and need so many!



Very Large Collection of Old Radio Valves | eBay

A pair of black PeeCeeBee V4 boards .
20USD + shipping
See link
http://www.diyaudio.com/forums/group-buys/307077-peeceebee-v4-gb.html

This is found in many decent units, I give it a 5 star rating.
Plus, it's relatively simple to make - but put it in a shielded box.
The power supply can be a simple 7815/7915 affair, and on the same board.

Greetings from an interested newbie to the DIY speaker realm.

I am going to be building a sub set up to sort of match some furniture.

The rears don't have many good options as far as a match goes but if a DML could serve well as a rear surround I have some decent options. The ceiling speakers can be worked around in a few ways but DML might be pretty interesting for that application as well.

Sorry if this has been previously addressed I looked around a lot and used the search function however I didn't find any discussions on it.

Is this a stupid idea because the surround effects are supposed to be lower and DML's are going to be too "loud" when driven by the decoding Amp?

My limited general understandings would be the DML have little bass response below 150htz is that a concern with surrounds? My experience is pretty limited and involved pretty crappy surround speakers in the past. Some Polk cubes that honestly never really sounded much better than an 8 dollar RadioShack 9 volt transistor radio.

Thanks for any feedback.

I'm trying to use PCBCAD40 to draw basic PCB designs, ie not using Schematic to PCB transfer, just placing pads on the grid and laying traces between them.

How do I just place a pad ?

I can place a component and tracks but can't place a single pad ?

I can't seem to be able to PRINT any results either.

Hi all,
I want to start this thread to answer questions related to using cadsoft eagle effectively. I have been using eagle for over 2 years now and done many layouts of single sided and two sided ones. Although sprint is preferred by many to make simple analog layouts, I prefer eagle because of its compatibility with schematic.
All you need is a carefully checked schematic and correct devices, voila you are guaranteed to have correct layout.
I dont say i have mastered eagle, but i would say i am about 60% proficient.

I still have no capability with making ulp's. never felt the need to, as there are many many ulp's available on internet that get the job done.

This is not going to be a tutorial thread, just question and answer thread.
and would cover questions related to the following topics
1. making sch
2. cloning an sch
3. making packages, symbols and devices
4. making layouts
5. Cloning layouts
6. importing gerbers for cloning
7. DRC for home etching and for manufacturing
8. generating BoM
9. Generating gerbers
10. Generating pdf's (positive images and negative images of solder masks and copper layers), mirroring them, etc
10. any other

In the process of answering questions, this thread hopefully will also lead to make me more proficient in eagle and help in finding something new which I hadnt used before.

Thanks and regards

Prasi

Hello,

I have a Korg B1 + S11 Regulated PSU for sale.

Korg B1 with best parts: Nichicon, Takman, Black Gates NX, TKD Poti, Elma Switch, Cardas RCA Connectors.

The S11 PSU is in my opinion the best option for the Korg B1.

The aluminum front plates are powder coated.

The price for both is 400,- € ‚ plus shipping.
I can unsolder the 6 Black Gates NX and reduce the price to 300,- €, plus shipping.











Kind regards

Andreas

Decided to keep this for now. Thanks for looking.

Hey guys, I need a favor if someone is willing. I have these parts and I think they are suspect, I got them some time ago from a vendor I have had luck with in the past, but I have limited curve tracing available to me. I have a total of 8 parts that I'd like to get tested.

I would be happy to pay if someone has a curve tracer capable of checking them out and matching.

PM me if you are willing and we can discuss the parts and payment.

Thanks

JT

I picked up a couple of these new Dayton 3 inch poly full ranges Dayton Audio PC83-8 3" Full-Range Poly Cone Driver for testing. I thought I share the results here as they were designed as a full range.

I was curious about using them as a midrange, the spec sheet indicated they should have a wide dispersion up to around 4KHz. They'll also do double duty as a test speaker an active cross over project.

The tests are geared towards off axis performance, distortion, and I did EQ them and listened for a while. The cobbled up enclosures will be sufficient for that purpose.

Index to trials:
1) Box 8L - Dayton PC83-8 (3") test results
2) Cylinder 4L - Dayton PC83-8 (3") test results
3) Box 8L + large baffle - Dayton PC83-8 (3") test results
4) MLTL - Dayton PC83-8 (3") test results
5) Omni opposed drivers - Dayton PC83-8 (3") test results
6) Le Cléac'h 7-Petal Horn - Dayton PC83-8 (3") test results
7) Le Cléac'h 11-Petal Horn - Dayton PC83-8 (3") test results
8) Fixing the Le Cléac'h Petal Horns - Dayton PC83-8 (3") test results
9) BP8 'subwoofer' to get some LF performance Dayton PC83-8 (3") test results
10 ) Bass Reflex - Dayton PC83-8 (3") test results
11 ) Tractrix Rectangular Horn - Dayton PC83-8 (3") test results

Hi,

I'm building a phono tube preamp from Valvewizard:

The Valve Wizard

With this power supply:

The Valve Wizard

I'm using the last schematic, without the voltage doubler. But I've notice that the 100k 2w resistor it's getting very hot.

My B+ voltage is 350V

And I use a switch with 12V led:

Aluminium Switch with Blue Light Circle 2NO2NC 250V 5A O19mm Black - Audiophonics

So, If my math's are right. I need a 33k 5w resistor?

Thanks.

This Tuner is an integral part of my Mum's system.
It has stopped responding to most of the buttons.
Free download pioneer fx 88 zl service manual
From the schematic, the buttons, all tactile switches not capacitive, all connect to the micro-controller.
I suspect the limit of my ability will be to ensure the mcu is receiving +5V.
Is there anything else I can possibly test for?

When on a station it appears to work perfectly.

I purchased a XMOS Multichannel high-quality USB to/from I2S/DSD SPDIF board from DIYINHK and when plugging in to USB port PC responds with "USB POWER SURGE"

DIYINHK is not responsive I really need this unit to work.

Has anyone found a better way to contact DIYINHK?

😡😡

Hi

After recently converting to 2 smaller (BK) subs for my main 2 channel system, I am wondering about building a powered bass system for my home office.

The components I am considering are:
2 x Dayton Audio DCS165-4.
Dayton Audio - DCS165-4 6-1/2" Classic Subwoofer 4 Ohm

1 x BSB200
BSB200

The amp is rated at 200w RMS into 8ohms/275 into 4 and AFAIK is what they use in their XLS200 subwoofer. The drivers are 100w/4ohm items.

My plan is to build all three into separate cabinets for flexibility - the sub cabs (small and sealed - not ported/PR etc.) will be stackable if that works best or could be positioned separately for optimum smoothing. The amp will have a separate accessible position. I plan to wire the subs in series (100w each).

The space under my desk is limited, hence small cabinets - I have had a BK Gemini II there before but it was impractical. I’m not trying to produce really low end, rather to support/smooth the area from mid 30hz up to the 65-ish area. The benefits in terms of soundstaging etc. of dual subs in my main system have been considerable and I would like to reproduce this effect if possible in the office system. The main speakers (on the desk) are Mission 731i and amplification is either an AVA Meastro 50 or an Arcam A18.

My main question is whether driving both drivers off a single plate amp will be an effective solution? Also, has anyone else done a similar build - effectively 2 compact passive bass modules driven by a single amplifier?

Regards

Alex

I have an active 3 way (Linkwitz Riley) speaker system with 6 60W amps, using Vifa 013-wh-00-08 as the mids. One of them has died, Im looking at replacements.

Vb for the Vifa is 2.2L, and so is the actual mid enclosure. I was contemplating Peerless 830860 as they get good reviews, which would fit with a bit of woodwork - its slightly larger and has flat edges.

For the Peerless a Vb of 4.8L comes out of Unibox. But since I cross over at 200/300Hz Im thinking an actual Vb of 2.2L wont make much difference. Is that a fair assumption?

But a max power input of 14W is suggested (The Vifa design comes up with 40W). Im thinking that means this driver isnt suitable for a closed box design? Or is that only going to be an issue if the design is used for bass/woofer ie not rolled off at 2/300Hz?

Any guidance is welcomed.

Hello,
Can anyone tell me how to indicate a score line on a pcb in Sprint Layout? I would like to add a score line to be able to snap a pbc in half.

Thanks
George

Servicing a Naim NAP135. Power switch is bad, no continuity.

Swiss made by EAO, the part number is 01-262-025.

Need ASAP for customer repair.

I have three 330VA 25-0-25 transformers that I've been using with some old LM3875 amps used for multi-way active experimentation.

I see these transformers would work well with the P3A. Any other designs to consider that would be a step up from the GC?

So, I bought a Harman Kardon HD7600 CD player to match up with my HK amp and tuner handed down from my parents, but lo and behold, when it arrived it no longer functioned. Many hours of fruitless searching and trial and error, I have a pretty good idea what's wrong, but I need to find an assembly that doesn't appear to be available anymore (pics below).

Does anyone know where I can get one of these, or even just a replacement spindle?

The player itself appears to work fine, but in its current state it simply spits CDs back out and refuses to play.

Also, is there a forum where I can get help with troubleshooting?

Hi All,

Completely new here,
I've gotten hooked on this DIY audio amp building.
My goal is to replace a Marantz 2226B with a DIY integrated amp. So far I have had good results, but not enough to beat out the Marantz ( it may never happen). I have 90db speakers and can blow go too loud with 4-5 watts. Personally I like lower watts.

So I have tried the Chip amps...but I love the simplicity of a Single ended amp. To me there's no sense in creating a class A/B chip amp if I already have a Class A/B amp...that sounds good.

So I want to find/ develop a circuit that uses a single gain stage single ended transistor amplifier. I had a darlington amp work...but not enough volume. I'm trying to stay away from mosfets- I always come up with more distortion on the simulator with mosfets...and seems to give me a headache when played...awsome transparency though...just too sharp on the highs.

So am I trying to do the impossible? I don't want to rock the windows to a rattle...detail is more important.

Thanks for reading this and for any help you may have.

I'd like to get opinions on building an attenuator that uses modern analog switches or a multiplying DAC. I've seen this method mentioned a few times and one example of a finished product but it seems it is still rarely done by the DIY community.

After searching through the forums there seems to be a lot of opinions on solid state attenuation but it looks like much of it is not based actual experience. It also seems that analog switches have a reputation that was gained 10 years ago but the analog switches available today are quite different, some having RON of < 1R.

The basic principle seems to be: VI conversion > R2R attenuation > IV conversion. There are quite a few very high end preamps that use this method, eg:
- Mark Levinson 32 and 38 preamps: Pic here.
- Luxman Luxman Electronically Controlled Ultimate Attenuator (LECUA, used is multiple products): Details here
- Accuphase AAVA: Discussed briefly here.

bbp built one, details here and here. Looks like it achieved very good results but he never shared the whole schematic.

While these implementations might sound complex with many analog switches and some ICs to control them, the same can be achieved with a single DAC and Opamp IC. Mark Levinson also does this. BV has mentioned a couple of times that he has achieved good results with DAC8043. It is detailed in the datasheet in figure 3 (VREF is the input):


Here is an Analog Devices Circuit Note about using this method for attenuation: Circuit Note | CN0025 | Precision, AC Reference Signal Attenuator Using the AD5546/AD5556 Multiplying DAC | Analog Devices

The DAC8043 might be good for testing as it comes in a DIP package but there would be better options once it was tested, like using AD5439 with ADuM7440 (SPI isolation) and a OPA1612.

I've attached a schematic using a DAC7800 and a dual opamp.

What do you think? Anyone experimented with this? An SPI controlled 1024 step attenuator that is better and more flexible than a PGA2310 and easier to use than a CS3318?

Here's a festive thread..... open to opinions of course, and preferences.
This is about two turntables, and what's important, what's not.
The make/models/etc will be announced after some comments.


But first, the SPECS.... which would you prefer?
TT1, or TT2?

Morning, I’ve been looking at the schematics of B&K and other mosfet architecture amps and it seems each new design had more mosfets. My AV5000 S2 has 4, the AV125.5 that replaced it had 6 and my old REF7250 had 10 per channel. That means to perform the same repair I’ve done to the AV5000 on a REF7250 would be a total of 50 mosfets, for 300 solder joints! Is the increase a matter of making the mosfets work less by splitting the amplification between more components or is there an increased quality of sound by additional power transistors? Or both?

I've got a pair of Dali Ikon 6 and will be getting a Minidsp 2x4hd- one pair input, two pair output (mid and bass). The Dali have 2 mid drivers and 2 tweeters, and are able to be bi-amped.

Can I sent one output of the minidsp to the tweeters and the other output to the mids? Good idea or bad? I'm new to DSP

edit: sorry if this is the wrong sub-forum. I didn't want to clog up the others with a non-diy question

I’ve rescued this old Leitz power supply from a container at work, it was used to power some kind of scientific equipment. Something had leaked inside of it, so I’ve gotten rid of all (weird!) stuff that was inside.

I’m now building a power cleaner out of it instead, and since I'm a complete beginner I could use some comments and help 😱

Inside it I now have a number of FO-felix’es. For a little bit of experimenting I’ve set them up differently; the ones with red coils I believe are 3A max (220v), the ones with copper coils are 18A max. The one with ATL written on it is a DC blocker, apparently potentially useful when used with a transformer. 2 of the boards are in line for mounting.

The big challenge I have is that I don’t have and cannot get earth in my apartment. All power outlets are only 2 wires 220v, phase and neutral. Naturally the chassis therefore cannot be earthed either.

All the pcb’s are fitted with nylon stand offs, but they are not yet screwed to the bottom of the enclosure.

I’ve fitted an IEC inlet with a fuse, and every FO-felix also has a fuse (after I bought all parts I’ve come to realize that I can’t even draw 18A from my outlets, so I could have used coils with lower rating but better supression of noise. And the 18A fuses seems to be redundant, as the mains fuse in my apartment would blow before these).

Does it look ok safety wise? Or am I lucky to be alive? Any tips or anything I should pay special attention to? Would safety be better if I used wood for the floor too?

Thanks !

I would like to build this RCA amp from tube manual RC-19. But I have not enough holes in my chassis. So I would like the to change the front tube to the subminiature 6N16b. Any suggestions for the resistor values to use in that case. CCS on the anode ? Or should I convert to a LTP with a ccs under it ?

im having trouble adusting the centre voltage on one channel only, which currently sits outside of the specified ranges of 0v +/- 30mv (currently varying up and down between 40mv and 50mv ) so i dont want to leave it.

the idling current is within limits, so thats ok
soft clipping has no infulence, nor does the impedence switch




with the solder short removed the pot is having no influence.
I have spares of these so ive elimintated that as it is perfect 0-1k


when you turn the amp on it works ok, so its a bit tricky tracing this one
ive checked for all the obvious things visualy, but i dont want to start pulling loads of components out unessesarily unless i realy have to as i could do more harm than good.😕



any ideas?


cheers

are your papers in order?
these days you need papers to go almost anyplace.
it's not enough to be vaccinated, you need to carry proof in the form of papers.
I wonder when they will start rounding us up for the re-education camps?
are your papers in order?

Hi there,

I was going through this DIY DJ mixer thread on the forum, and I noticed there was some talk about a very basic DJ mixer set up (mancuso inspired) where say for example: you have two turntables, then you connect the turntables to two phono amps, and then you run that to I guess what would be a summing amp (??) and then run the "resulting" signal to your amp and furthermore speakers.

I thought this was really interesting. The possibility of having a very simple mixer with two stereo channels in and one (maybe another for cueing) stereo channel out as a basic unit which you could then add an isolator or filters to in the output stage could be really great. Because, once you take a DJ mixer and remove all the eqing and effects, you're basically left with a summing amp with phono stages right?

my idea was to just get two really nice phono amps (possibly tube, and yes I'm aware tubes are **** in terms of fidelity, but pleasant coloration can be nice sometimes) and then hook them up to a summing amp and then maybe just get an isolator for the master output if I want to eq it...

So, I guess I'm looking for a simple/reliable summing amp schematic someone out there might recommend. And, also, would this be possible to do with a passive summing box type setup? I don't think so right? why?

Any input is greatly appreciated.

Cheers,
ben

Sale:
6J32P — 46 pcs. for $5 ea.
6N6P — 44 pcs. for $3 ea.
6N6P-I — 333 pcs. for $3 ea.
6N8S — 78 pcs. for $2 ea.
6N9S — 9 pcs. for $2 ea.
6N23P — 54 pcs. for $10 ea.
6N23P-EV — 33 pcs. for $20 ea.
6P6S — 84 pcs. for $3.5 ea.
6P14P-EV — 400 pcs. for $10 ea.
6P14P-ER — 400 pcs. for $12 ea.
6P3S-E — 100 pcs. for $7 ea.
6S4S — 13 pcs. for $25 ea.
GS35B — 10 psa. for $100 ea.
GS31B — 7 pcs. for $70 ea.

Hi All,
A friend of mine sent to me a board for this old preamp based on Marantz 7. As I need a pre with a veri high gain I thought to this pcb that lays in a drawer.
I thought to eliminate the NFB to improve gain (and maybe sound), but I need your advice for any other improvement.

ive seen some bodge jobs, but go knows how whoever got it like this
its drawing quite a bit of current on the lamp tester, but all fuses are in tact so hopefully i wont have to work too hard with it


biggest challenge is going to be making something reasonable out of whats left of the board