What do you say about making a list with reference DIY amplifiers?

I've seen lots of people that are searching for the "best" amplifier schematic. It would be useful for them(me included) to have a list with all of the DIY amplifiers that are the most popular around DIY builders and that can compete with high-end commercial ones.
A little review about it's design/overall sound would make the choosing easier.

I don't see a forum dedicated to active speakers. Amp power and DSP comes cheap these days so surely most new speaker builds are active? I note that there are a few 'active' threads in the Multi-Way speaker forum but the forum states it's for conventional speakers with crossovers, I take that to mean passives?

This type of compound amplifier uses an OTA instead of OPA input stage. It works only with bipolar input amplifiers. The OTA is a transconductance amplifier transforming the input error voltage into output current. The AD844, has the output of it's OTA available labeled Tz which can be used to drive the main amplifier. The input of the main amp and the output of the OTA being both of high impedance, the capacitance at this point determines the dominant pole. Here it happened to be about 15khz, but with an extra gain of 60db. The OTA then provides the main amp of gain 10 60db more NFB to smash the distortion.
The adjusted values for LM3886 gives for 60db extra NFB, phase margin of 62°
Hayk.

I thought I'd share this one.

My father was an old school Engineer and worked one everything from
aircraft to underground mines, but did not understand electronics.

At one place he worked he setup a unique way to run multiple
audio sources to each of the other engineers desk / drafting tables.

He had about 3 or 4 radios each tuned to a different station and then ran
wires along the wall to each guys desk where each had a set of headphones
with alligator clips on them. They would clip onto the wires of the source
they wanted to listen to. So those wanting talk radio would clip onto one set,
classical music another, etc. I get a chuckle at his solution but it did work.

I've just ordered two of the breakout boards for the ALPS pots. Can someone point me to the right connectors on Mouser? There seem to be a billion of them....

What class of ceramic cap is shown in the center of the pic attached?

In the circuit where it is used, can this ceramic cap be replaced with a modern MLCC C0G ceramic? This cap is C405a circled in red, and connects across the emitter and collector of TR404a.

TIA 🙂

JL Audio 300/2 V1
13.8v supply, 275mV input, 4 ohm load each channel @ 50hz input signal, crossover switch = off, gail fully CCW, full range x1, filter slope 12dB, input voltage set to "low". Please let me know if you need more setup info.

All 8 IRF540's replaced in the output. Originals were shorted, cracked, burnt.
I am having a hard time isolating the ringing on the sign wave of channel 2.
This anomaly starts when the load is hooked up and is not present when the loads are disconnected. This ringing increases substantially with increased input voltage.
I am assuming it is an issue in the channel 2 feedback but I am having a hard locating the issue.
Is this negative side ringing or oscillation due to a leaking transistor or diode in the feedback circuit? Or am I way off in my assumptions?
In the pictures blue is channel 1 and yellow is channel 2.
One picture is zoomed in to roughly 13ms to the right of the trigger showing the comparison in the channels when this ringing starts.
Tips on where to start would be appreciated!

Closed.

Probably basic but I'm having trouble with it...

I'm trying to find mica insulators (if someone knows something better please advise) for Toshiba's 2SA1987's and their complementary pair. It seems their package is the 2-21F1A, which is the same as TO-3P(L) as per some thread I found here.
But looking around at mica insulators in most common electronics sites I couldn't find any insulator specific for this package. Does anyone know what are the differences between all of the above packages ? And can I use insulators for TO-3P or TO-3PBL (that's what I found on BDent...).
THanks!

Good day all,

Could anyone assist with troubleshooting this issue.

Amplifier when powered up plays fine, no issues. When powered down (remote turned off) there is a noise at the output like a zuuupp noise as though the mosfets are stll on after power down and the are switched of after remote is disconnected or a cap is discharging and the clip led would flash for a second and then go out.

Any recommendations on what maybe be the cause.

Thanks

Hello everyone, this seems to be a some what uncommon issue as I can't find anything related to replacing them or about adapters. I am working on a Yamaha CX-1000 preamp that has a cooked NJM5532SD opamp in the left channel of the phono preamp. There are no existing trust worthy subs that I can see even though it is just a standard 5532 opamp shoved into these darn strait 9 pin packages that appear to not have been made for a long time.

Because this is a repair for a customer the job has to be neat and tidy, otherwise if it was my own repair the ol hard wire it to a smt type 5532 would do. So I am hopeful that some one has ran into this issue and may possibly have found readily made adapters for standard opamp packages?

Just curious if anybody has done this and gotten good results... I’m about to get a set and I’m already thinking about it

I have a passive crossover I was using in a car audio install. The tweeter was dropping to very low, muffled output... then would cone back at random times. Now it just stays at very Very low output. I hooked up the crossover to a different speaker and a different amp to isolate and confirmed it’s the crossover causing the issue. It’s a good one and I’d like to get it working again but don’t know where to start or what to look for. Capacitor gone bad maybe? I’ve got a ddm and general knowledge. I think I could do it with a little advice. Would appreciate any thoughts on it thanks!

Could the 8 ohms drive 300 ohms headphones?

Hi,

I am not sure this is the best forum for this, but...

I have a Beolab 3500, "mk 1" with MCL and Masterlink inputs. I would like to run it from an phone/tablet. There is a company that makes an iPod adapter cable, so it can be done.

Does anyone know the connections for the B&O MCL 7-pin DIN socket?

Thanks for any help.

Some time ago I found examples for bass reflex port tubing with holes (this is a german article but for reference: the first measurement compares the perforated and none perforated bass reflex tube) and for speakers using flexible material for the tubing (page 16-17), both to reduce overtones in the bass reflex tube. While both approaches are understandable in their concept I am missing further details to fully comprehend them. For instance in the german article it is pointed out that the length of the tube has to be longer by 2^0.5 when adding those holes. Wanting to dive deeper into the topic I tried to find some more articles and measurements. However, my search was unsuccessful.


I was hoping if someone of you could point me in the right direction. Is there no more research available or do I simply dont know the correct terms to search for?

Hi!

I'd like to hear your suggestions for a 12 inch woofer. I have an 80 L vented box and I'd like to achieve the low end at least 40-45 Hz. Also imprtatnt that the speaker is sensitive, around 93-5 dB or more.

Thanks!

This is my first post, so please be gentle!
I started building a copy of Nelson Pass speakers, I saw in a Sterophile interview of his. The open baffle design is quite simple. My question is this: I have listened to the Cube driver- amazing! But I also listened to an open baffle design with Audio Nirvana 6.5 driver and to my ears-regular, not golden one's, it sounded excellent as well.
Do you think that the cube f8 deserves the extra cost? Has anyone used Cube and Audio Nirvana full range drivers?

I built a ported enclosure for my Insignia NS-B2111 and am using them as my rear channel speakers in a home theater setup.
I tried crossing them at 80hz but they break up during reference volume peaks.
I had to bump them all the way up to 110Hz!!

As such, I'm wanting to find another woofer to drop into my nicely built DIY enclosures, that will take more abuse.

I have a pair of Dayton RS180P-8's which is the largest size speaker I can fit, but unfortunately it looks like they want a much larger enclosure.

So I need to find a woofer, but I need to know the Xmax of the Insignia NS-B2111 so I don't buy another woofer that is just as "wimpy" as the B2111.

KT88 Genalex Gold Lion reissue vendor

Why is it that difficult to buy them outside ebay?
It’s supposed they are built in Russia. Is there any EU trustable sealer?

hi everyone,

what is the purpose of increasing the transformer VA or capacitor farad when the output is limited.

can this help in improving sound or whatsoever?

increase the trafo va and capacitor value, which 1 is more reliable and worth it.

Yes, so after finishing off that Mini-A have been working now & then on a (somewhat) low-budget F1 clone build based on some PCBs suds offered.

Tonight fired it up, did measurements & all is fine with it (after that big, ugly 5 ohm 10 watt paralleled w/R27 got both channel offsets < 20 mV).

It's top will be all heatsink (hinges in the back so its 'hood' can be lifted). Also plan to use amb's nice ε24 pPower switch driver circuit & use rear-mount screws in the faceplace so that only the centered vandal-resistant/LED switch will show.



Another big thanks to Nelson for making it possible for this sort of thing to happen

The fine print:There is the question of whether suds PCB offering meets the non-profit requirements for the use of the IP... At $100 USD for 2 full sets of boards shipped to US (total: 4 amp & 2 PS PCBs) covering alot of square inches & this single 2-set run/request, I'd think there is little or no profit. Just the small run based on PCB area would probably be several times that price from ExpressPCB for example. But by the looks of the marketplace thread, this offering didn't follow the traditional group buy way of things... There are a couple minor issues with the boards, like somewhat small traces, small pads & small holes... But no biggie for sure & silk screening is correct & matches the BOM I was able to construct.

Guess I'll post back after she's done (more alum shavings headed for the garage floor )

It has been a while since I posted here since I didn't do any relevant audio projects since my LKS ES9018 and Lehman projects.

My tweaked LKS ES9018 project defected last summer because of an overheated ES9018 chip during summer heat in Hangzhou. I didn't bother to fix it for a long time and ran onboard audio (ES9018K2M) which eventually started bothering me. I started looking for a dac with a newer ES9038Q2M chip since I love the sound of my ES9018. When I was looking into the Topping D50 which has dual ES9038K2M in mono mode and excellent measurements on ASR, I ran into the DX3 Pro in their factory Taobao shop that just came out. Dual AKM AK4493 (upgraded AK4490, which is decent already). DSD512, PCM768, BT5.0, remote control AND powerful headphone amp! The measurements on ASR are near D50 but the featureset of the DX3 Pro is far more extensive. The D50 lacks BT, remote and headphone amp.










So after some consideration I ordered the DX3 Pro at 12.12 for 1085 RMB (€140) and inmediately ordered a 15V/1.5A LPS with it for 360 RMB (€45). Even though Amir his measurements on ASR showed that an LPS wouldn't improve sound too much compared to the original 1.0A switching brick. Later I found out that many devices had issues suddenly going into standby mode and topping themselves hinted on using another powersupply to see if the problem was solved. So far on all three of my units (later more on why I have three) I've had NO issues with that so far. So I'm glad I bought a solid powersupply anyway.

I hooked it up straight into my QMS Q5s and was really impressed with the amount of detail and imaging the unit produced. But there were some things I didn't like as much. The treble seemed a bit harsh and crisp out of the box and the bass was lacking in the lower frequencies. It was tight but not deep as the LKS ES9018. Also the soundstage is more narrow and it's less holographic. In general I'd say the ES9018 is more sophisticated and musically pleasing. and the AKM is more analytical and a more in your face with vocals. Don't get me wrong. The ES9018 is a highly tuned DAC carrying all kinds of expensive parts and opamps in class A. So I figured there must be more potential in the AKM. A couple more days of burning in smoothened out the edgy treble a bit but didn't bring out the bass in any way. This is when I decided to hook up my Lehman and it helped but I still felt there is more to be squeezed out of this unit.




And this is where I come to the part that I opened it up and planned to modify it.

In the next posts I'll share my modifications and plans to do so. I hope people get interested and join in. In another forum (which I won't call by name) a lot of people were already making modifications and encouraging eachother to try modifications but some elitarial upperclass started moaning about measurements and complaining about audiophile territory. Hostile environment. So I'm here hoping we can share and contribute and keep it nice and positive.

need Bang&Olufsen Turntable pinout

I have a Beogram 4004 with a 5 pin DIN and was wondering if anyone here has the pinout?

I want to make a "nice" Pi streaming box.

A pi 3 or pi 4 in the usual pi case will work nicely, but if I put it (and the power supply etc) in a nice metal case, the built in wifi antenna won't get much signal.

I have found a mod for a pi3 so that it has an external antenna, which I could put outside the metal case.

External antenna modifications for the Raspberry Pi 3 | DorkbotPDX

Does anyone know of a similar mod for the pi 4?

I could use an external USB WiFi adapter, but that seems dumb when the pi has it built-in.



BugBear

Hi just wanted to spread the word that i'm selling 2 used Dayton 12" 8 ohm reference series subwoofers.


Dayton Audio RSS315HFA-8 12" Reference HF Subwoofer 8 Ohm | eBay

Dayton Audio RSS315HFA-8 12" Reference HF Subwoofer 8 Ohm | eBay

I started down the JX92S minimonitor route more than five years ago. A couple of years back I developed a Jordan JX92S crossed to a ribbon tweeter which received very good comments from listeners.

Recently I built a MLTL which incorporates the Jordan JX92S and Aurum Cantus G2si ribbon as drivers. The MLTL is a slight modification of GM's 48" design. This design marries the exceptional performance of the JX92S with a high quality ribbon as used earlier in my mini-monitor design. The MLTL achieves a lower F3 point (I'm getting below 40 Hz in my measurements) than the mini-monitor could do. The sound is very nice indeed as you have the enough bass impact to satisfy most people yet a very petite size enclosure. My unit (see picture) is constructed from solid cherry side cheeks and MDF. I used Martin King's spread sheets to slight reduce the internal height to 46"and to optimize the port tube length vs. Greg's design. The external box dimensions are 7.5" W x 6.5" D x 47.5" H so the overall package is relatively small for a floor standing speaker.

I also included an external switch to permit me to use either the crossover network between the JX92S and the G2si or alternately to just use the JX92S full range with a baffle step compensation circuit. Thus one can compare the full range driver performance vs. the crossed over version very easily!

I'm thrilled at the performance of this speaker as it handles most material with ease. While it may not suit a hard rocker, it will satisfy a lot of listeners.

Jim

Hey,

I am building 3 way speakers, and after a long design process i have selected these parts. I decided to build my own crossover. See the pictures for the parts list and the crossover design. Would love you guys feedback and comments on my selection. Do you think it would work? And do you think building my own crossover is a good idea or should buy a premade?

Thanks in advance!

This sublime sounding, 45kg (100lb), hot running Tim DeParavicini designed delight has been gathering dust on my equipment shelf for a year and a half now, (having started smouldering one evening) while other audio projects have taken prominence.

I'm now ready to leap in, scope and soldering iron all fired up, but unfortunately, I don't have a schematic. Anyone out there able to help me out?

Thanks in advance.

Hello,

I want to mod a sega saturn to output spdif, i need it for my dac + amp + speaker combo. The saturn provide an i2s signal with a master clock, so it shouldn't be very hard to do...

There is a known mod that can be done to do it, most people use a basic CS8406 board to do it.
As i had to make an order at audiophonics, i bought this i2s to spdif interface :

Digitale Interface I2S vers SPDIF BNC WM8804 - Audiophonics

This thing has a terminal block for a 5v DC plus the i2s input. Strangely there is a DATA 1 and DATA 2 on the i2s input, i don't know why.

My saturn is a model 2 japanese with a TDA1386T dac. I get the 5v DC from the pin 9 - 10, i check with a multimeter and it's fine. For the i2s signal i connect this way :

MCK to pin pin 12 (sysclk)
BCK to pin 4 BCK
LE to pin 5 (word select input)
DATA to pin 6 DATA (i2s Data)

For the GRD, two cable connected to the pin 9 (digital ground) go the the i2s grd connector and DC terminal block ( - in the photo).

The spdif kit power on, tension is good on the dc terminal. I connect it with toslkink and there is light, but no sound. I check the tension in the i2s input, i get between 3.2v and 1.7v depending on the input, so there is no problem with the connection.

I hate these chinese board because audiophonics do not give a s*** to give correct technical information and the technical service don't know much better. I have problem in the past and now it's the same story, i won't even ask audiophonics it's a pure waste of time, and every info i could find on these board are of course in chinese.

This board has a i2s input and output, plus 2x spdif output (toslink and rca / bnc). I start to think there is a way to choose between the i2s output and spdif outputs. I check the tension on the i2s output and there is the same voltage as the i2s input, so the i2s out is active. There is no sign of jumper in the front of the board, but in the backside there is an IC close to the i2s input, and two resistor (R20 R21) that can be put in different position.

https://zupimages.net/up/20/32/5idx.jpg

Any idea ?

I need a diode to replace a shorted SB2100 in a TV power supply. It’s a 2A 100v schottky. I’ve read you don’t want to replace Schottkys with silicone as the Schottky is a very fast diode. What if you have a very fast silicone?

I’m trying to find one I have in my stash as a replacement. The pulse speed on the SB2100 is 300 microseconds.

I have a couple of the RGP25M-E3/54. It is a 1000v 2.5A and it is an ultra fast with a speed of 500 nanoseconds. Converting to nanoseconds the SB2100 takes 300,000 nanoseconds. So the RGP is much faster.

Am I looking at this wrong? Is there any reason I couldn’t use this diode as a replacement?

Dan

I understand Firstwatt's design/architecture philosophy from reading the website. When someone like Nelson sits down to design a new amp, what is the determiner if the amp will be balanced or single-ended RCA?

Most of Firstwatt's products are SE RCA input, and few are Balanced XLR input. I imagine cost of the additional parts is part of the decision.

Seems like balanced inputs are more flexible as it allows for both typologies. Curious why the trend at FW is SE only designs?

Thanks

Hi All,

Does anyone have a schematic diagram for the Orion XTR2500.4 amp?

It is a four channel Bipolar Transistor output section using TIP35C and TIP36C devices.

I am measuring +-53V on the rails and that means that the outputs are seeing 105V when the signal is at its maximum for part of the wave form. Is this not exceeding the VCEO 100V limit of the devices?

Likewise the drivers are TIP41C / TIP42C, am I missing something?

Thanks in advance!

Wondering if there is a good healthy pair of these in anyone's possession they would like to sell. I sold 2 pairs 10 years ago, found myself missing them.
I'd like to rebuild the speakers I had with the 8543's (North Creek Image) in the 90's and 00's for nostalgic and sq curiosity. Still have cabinets, tweeters, xo components.
Worth a try...
Thanks, Don

I purchased a Sony receiver DA3500ES on CL. Circa 2010. Worked fine until...


it has a physical on/off switch that you can leave on (standby?) and work off remote. I had left it in standby for a couple days. While in standby, it spontaneously started clicking. I can turn off the physical switch, and when turned back on it starts clicking. I tried the various button combinations from the manual for clearing, but no good. It doesn't make it far on enough on startup to display anything... just starts clicking. I removed speakers and components in case of a short. No good. I removed the top, and the clicking is in the area of the power cord entry to the inside. Without taking apart, I did not see any blown fuses, brown boards, or leaking components.


I read everything available, even for other manufacturers. People talk about a main power relay and capacitors. I'll admit I'm trying to fake my way through in order to get value from the unit. I don't want to electrocute myself, but it seems like it should be one discreet problem that would turn it around.

Hi All,


I have an issue with my DAC, every time that I switch tracks or inputs there is a noise for a second, the noise doesn't appear during playback, when when I switch tracks.
I believe it's related to some kind of mute "mechanism", I can see relays on the pcb that clicks when there is a signal lock.


Any idea or suggestions?


Thanks

What class d amplifier board should i get if focussing onto a 2.0 System while using Speakers that are 6ohm (as alternative 8Ohm)

I've read that 2x100W with dual TPA3116 is just bridged so 2Ohm Speakers can be used and do not provide more Power with 6Ohm Speakers than single TPA3116

is that true?

I want to order this one as dual TPA3116:

Bluetooth Verstarker Board HiFi Stereo 2.0 TPA3116D2: Amazon.de: Elektronik

or that one as single TPA3116:

Bluetooth Verstarker Board HiFi Stereo 2.0 TPA3116D2: Amazon.de: Elektronik

than i have read that coils with 33mH (as used mostly on dual TPA3116) is not ideal for 6ohm speakers

the dual one above has 15mH coils and the single tpa3116 has 10mH coils

​Hello,
I have a Pioneer SR-60 Reverb Amplifier unit and although it says "Reverberation Amplifier" it's actually a Delay, it uses a MN3008 BBD delay chip.



It would be great also to be able to change the Delay Time and the Feedback level.

here is the schematic for the unit:



https://i.imgur.com/JVhDN9V.jpg

The schematic is a bit confusing to me because of all the switching going on,
I need help from you guys.
How do you think I could implement a control the Delay feedback and change the Delay time even if Limited??

Thank you so much​

This is one of my SE amplifier , last build .
Inside an Pioneer Amplifier case .
It is made with 6n2P in srpp follow by a 6P3S final class A tube.
It has a smps power source and a control/selection/volume with shunt control by an atmel atmega16 with IR remote control.
Some big pictures with inside:
http://i40.tinypic.com/ohn6gx.jpg
http://i29.tinypic.com/wrkp4i.jpg
And the schematics are :
amplifier
http://i26.tinypic.com/jp7iwg.jpg
smps power source
http://i29.tinypic.com/mw9zph.jpg

I am wondering if this idea has been explored and is worth it?

The idea is to use rubber gaskets to sepoerate the front face of a speaker cabinet (with its virbrating drivers) from the rest of the speaker cabinet, to reduce vibration.

With this idea the only direct wood wood connection is the screws, unless I used very strong silicone gasket glue or some other selant like Selleys 300g Clear ArmourFlex Adhesive Sealant | Bunnings Warehouse

Thanks for any feedback.


Added on after reading: Disclaimer, "I am a beginner at this." Yes, very helpful posts below. I can see the LS3/5A had a baffle gasket, like Loudspeaker Gasket Baffle sealing strip self-adhesive 6mm wide applied as in http://www.g4dcv.co.uk/ls35a/pics/35atopsection.pdf . Then also for the LS3/5A to isolate the driver from the baffle like with LS3/5a BLACK PLASTIC CHANNEL STRIP for sealing B110 front edge. Not found pictures, but understand can isolate driver bolts, with O ring and in grommets. I also read this article on audiopress.com, which cautioned about a non solid connction which can affect sound clarity.

I'm trying to revive my SL-P8 CD player which has a couple of issues

Firstly, when searching through a track it will skip back 20-30 seconds repeatedly so that it will never progress its search. I thought maybe its because of scratches/dirt on the cd, but I've put a rough cd in it and it seemed to search slightly better for some reason. I've also tried my best cd and it does the same on that.

It also on occasion struggles to play the 1st track like its stuck on reading TOC. If I play the 2nd track and then skip back to the 1st it will then play

Any help will greatly be appreciated

I have found some of the best pliers in USA for nearly nothing, he keeps selling 5 at a time but for some strange reason, cant he get the system to allow people from Denmark as byers. He have tried, I have also contacted ebay but with no result.


If you please will help me to bye the pliers and ship them to me, will I be super happy. I do pay in advance of cause! 🙂

I'm planning a preamp utilizing a pair of these controllers (remote function as well as the knobs). I'm trying to figure out how to create the front panel. Either the panel with the inset screen or better, the arrangement of holes for the individual lights to shine through. Front Panel Express is a possibility but I want additional ideas. The chassis has a lip on the inside which means that all machining has to be done from the front if FPE does it. The circuit board is not exactly what the unit looks like but is similar. BTW, what is that type of light emitting chip called and is there a standard light pattern?
TIA
Dave

Posting here, cause I plan building discrete STK 4241.
(typo in the post heading)

Could I remove the output chain (higglighted).
I guess it is a bushero network.
Space for implementation is limited.

Can I compensate it with some change in the internals?

JBL speakers for sale. Unfortunately just one horn.
Condition 9/10
Location Norfolk, UK.
Open for offer.
Thanks

JBL 2206HPL x 2 sold
JBL 2402H x 2 £200
JBL 2447HPL x 1 £120

Hi all and Victor,

My 8600SVK is on the way - very much looking forward to getting it up and running. 😎

I will mainly be using it as headamp for my 1266 Abyss off the speaker terminals.

For this application, 2A3 would suit better than 300b tubes - 4W per channel would be safer in this case, plus it seems that 2A3 tubes are arguably cheaper for better quality, and the audio stream may be improved. It would also be excellent to retain the 300b functionality should I require more juice to power speakers.

Obviously, some mods are required - will need a different R-Core trans.

The TU-8233 already has this feature and even includes auto sensing, which I presume would be tricky to implement in the 8600. However, perhaps the 8233 R-Core transformer can be used in the 8600, probably with a manual switch between 2.5V and 5V.

Also, I guess the plate voltage on the 8600 is 330V? This is too hot for the 2A3 which should be 290V - perhaps this can be also regulated through switching in order to get the best of both worlds?

Would this be viable and how could I get my hands on a Kitamura Kiden Pheonix EK TU8233 power trans goodness?

The other alternative is a 2.5V filament transformer, but there is little space to place one in the chassis of the 8600.

The other mods I am looking to implement:
- a bypass switch for the inputs so it behaves as a power amp (I have a headamp GSX2 to use a pre).
- maybe a stepped attenuator down the track?
- switchable output between the 8ohm speaker terminals and an additional 4 pin headphone XLR jack.

Cheers!

Like a tossed bottle into the sea, I query help for a broken analyser. Web searches did not return any information... Any documentation will be appreciated 😉

How do you store all the different test-cables for electronics? There is scope-probes, DVM-wires, custom-wires, banana-plug-wires, RCA, Phono, and the list goes on.

I like the solution where they all hang on the wall, but that takes up a lot of wall-space.

Whats the clever solution?

Kind regards TroelsM

On the off chance that someone has a surplus pair in their stock, I'm looking to buy two of these rare VFETs.

Hi!

What do you think the problem of this amp? I have 3 amps with the same problem. It muted with dc out 1.3v but the two channels working fine. They uses irs2092 as their driver to mosfets. Thanks!

Selling my Creative Sound Blaster ZxR. I purchased it to have a hifi/audiophile solution for my desktop. Its been great. But I just spent a ton of money on a replacement and I don't need this anymore. Comes with original box, accessories, and everything you need.

Amazon.com: Creative Sound Blaster ZxR PCIe Audiophile Grade Gaming Sound Card with High Performance Headphone Amp and Desktop Audio Control Module: Computers & Accessories

Retail: $229.48

Offered at: $140

Sound Blaster ZxR - Sound Blaster - Creative Labs (United States)

---





The flagship of the ultra high-performance Sound Blaster Z-Series of sound cards, Sound Blaster ZxR elevates the standards of technology and performance for the future of PC gaming and entertainment. Boasting an unbeatable SNR of 124dB, it includes a DBPro daughter board and Audio Control Module for unrivalled audio playback and content creation.

Signal-to-Noise Ratio of 124dB
A signal to noise ratio or SNR of 124dB means your audio will be more than 99.99% pristine, which is over 89.1 times better than motherboard audio.

Studio-grade Content Creation
Add studio quality audio sound tracks or voice tracks to your video clips or home videos created with hardware that uses only audiophile-grade components such as 123dB analog-to-digital converters (ADCs) with RCA Aux-in and optical inputs for outstanding recording quality. With the 600 ohm headphone amplifier, you can do studio-grade monitoring as well.

Customizing audio with swappable op-amps

Why do some advertisments refer to transformers as "cattle"? Something lost in translation?

So i am working on a Punch 75HD with one bad channel. I narrowed it down to one the punch amp modules. One of the SOT23 SMD is:


Is this a 3.3v zener diode SOT-23?

On page 2 its the module with 17 pins.
View attachment rockford - HD-ModuleSchematics.pdf

I look for FM stereo tuner board for a multiple radios control system. Reception must have enough quality for mastering emitters.
I didn't find any item with usual low cost modules providers (AE, Ebay, bangg...)

I can use autoradios but I prefer to integrate modules in a rack.

Any pointers ?

Hello everyone,

I don't know if this is the right forum, I'm looking for a Bluetooth PCB with the Qualcomm CSR8675 APTX-HD and LDAC chip.

I found a PCB on Ebay, but I would like to know if there is a message or connection music. I want a PCB without message or music.
The seller doesn't know.

PA214 Bluetooth 5.0 Audio Module BT5.0 CSR8675 Chip Support APTX-HD Finished | eBay

Im planning to use a waveguide with shorter depths like 1 and 2 inch deep with diameter close to 8 inch Im looking made up of MDF wood routed accordingly.

I have few doubts that can a 1 inch and 2 inch deep waveguide either it could be radial or soft hyperbolic horn would gain 3db? or slightly more.

As per the data observed on some tweeters with wave guide and without waveguide not just off axis improves but also some sensitivity in the lower frequency of the tweeter region. Which is exactly what Im looking not to have too much peaked gain but somewhat 3db is also great enough.

https://meniscus.lightningbasehosted.com/wp-content/uploads/2015/11/SB26STAC-C000-4-Data-Sheet.pdf

https://meniscusaudio.com/wp-content/uploads/2019/12/SB26STWGC-4-Data-Sheet.pdf

compare the above two tweeters one with waveguide and one without a waveguide. So the boost of 3db happening with the short waveguide?

Wondered if anyone had built and or listened to Doug Selfs precision preamp published in August and September 1996 in Electronics World ?

The Signal Transfer Company: Precision Preamplifier

Dougs tone controls with adjustable turnover frequencies look interesting.
The whole design uses NE5532's and does have a fair few electroylitics in the audio path, mainly to keep any offset current out of the pot wiper as it uses NE5532's. Using FET opamps looks a possibilty and would enable these to be ommited.

Anyone any experience of the design in practice 🙂

I have a question for US based DIYers. Often in dathasheets I find a paragraph called "Engineering specifications". It contains sentences with "shall be". What is the purpose of it?

I am wondering these so-called audiophile fuse are snake oil stuff. No doubt what they talk about make sense since the power goes through such a tiny wire blah blah (like low awg vs high awg cables).

But I am wondering if the fuse can affect the sound, then why don't we use circuit breakers instead? The amount of contact for the power to flow is greater than any fuse. Wouldnt this overcome the problems of fuses?? Downside is that they are alot more expensive compared to stock fuse but still way cheaper than those "audiophile" ones.

https://www.mouser.sg/datasheet/2/645/D_1410-L1_ENG-1107764.pdf

https://www.mouser.sg/datasheet/2/358/typ_TS-709-1275960.pdf

The OEM radio in my Dad's 2000 Ford Ranger died and I would like to repair it, but I've looked everywhere and I can't find any schematics.😡


Anyone know of a source?


Thanks
Gary

My home is being remodeled. The wall that is for electronics is where the front door opens. I have put floor standing speakers there but with new construction this will not work so speakers on-wall or in-wall or some kind of custom column will be the path. the room is 1500 cu.ft. the wall is 9 ft wide the other 2 feet will be cabinet/shelf for TT, pre, amps, vinyl etc. Tv will be 65 in. no surround anywhere. I will be using Nord 8 ch for active 4-way with minidsp. The other side of the wall will be closet in my wife's office so space isn't a huge issue behind the wall but i think sealed over infinite baffle is preferred by my wife. the speaker layout and design is where i get lost and need help. It looks like $2500 for drivers is about the top of the budget and i have looked at several of options. Layout, size speakers , brands are all open. i was thinking of using Aurum Cantus g1 and AST25120 Aero for tweeters. I do like the way ribbons and amt sound.

I am a newbie to this forum and to speaker construction. I recently purchased a center channel speaker kit (two 5 ¼ inch woofers, one 2-inch square dome tweeter, and a crossover). The cabinet will be enclosed (acoustic suspension enclosure). The kit instructions indicated that the cabinet’s inside dimension should be about 13 inches by 7 inches by 7 inches, with the outside dimensions of the rectangle as 14.5 inches by 8.5 inches by 8.5 inches (using 3/4 inch MDF). The internal volume should not be more than 0.75 cf model. The drivers will be arranged on the front baffle as woofer-tweeter-woofer configuration.

After reading a lot of online information, I have a number of cabinet construction questions that I need help on.

1. What is the distance of the woofers from the edge of the rectangle baffle?
2. What is the distance of the tweeter from each woofer?
3. Should the tweeter be recessed, i.e., flush-mounted?
4. Should each woofer be flush-mounted?
5. Is bracing needed inside the cabinet?
6. Is suitable gasket material (Rope caulk, electrician dope, duct putty) needed when securing the drivers to the front baffle?
7. Does the front baffle need to be built with two sheets of ¾ inch MDF?
8. Should the front of the cabinet baffle edges be rounded over?

I thank you in advance for any construction advice you can provide

While working with a crossover and thinking about polarity, I had the thought that unless there is some kind of standardization in place, the + and - marked terminals on a driver only have meaning for that particular driver model, or possibly manufacturer. If I mix and match brands of woofers, mids, tweeters, who's to say that applying a positive voltage to the + terminal will make all the cones move in the same direction, since it depends on the direction the voice coil is wound. Is this a valid thought or am I missing something?

I recently realized an old dream and got my hands on a Sony R1 & D1 combo and they are and play beautiful. Is there anything I can do to prolong its life? Anything I should be obs on or should check or inspect?

Hi,

These Mosfets are used in the Power supply: 80N08A N-Mosfet.

I can't find the 80N08A anymore.

I used the 80N08S2L-07 but it don't works. I think the reason is the lower Gate threshold voltage. The other parameter are similar except "Rds on" , is lower too.

Maybe the 80N08S4-06 works?

Anybody an idea for replacement?

https://www.mouser.de/datasheet/2/196/Infineon-IPP_B80N08S2L_07_GREEN-DS-v01_01-en-1226216.pdf

https://www.mouser.de/datasheet/2/196/IPP_B_I80N08S4-06-Data-Sheet-10-Infineon-1228187.pdf

Hi, what do you think about the inductors, the air core ones are better than the conventional ones and for the frequency cut-off of the MKP or electrolytic BP condenser bass?

Hi guys
I want to buy a B225s and a 20 watt speaker and start an amplifier project with it. Someone can tell me where I can get a cheap sample of it
------
irenx

I was a little surprised to see someone listing a used F6 clone on Ebay UK and Head-fi for £1500.
I'm not sure this goes along with the spirit of Nelson's generosity. I suppose
it's a one off and not the same as the EBay seller knocking out clones even now he has removed references to NP.
So is this a record price? Does anyone feel like me or not?

Hi all
I know that this is not simple argument and not all agree about this topic but I'm not able to progress on my project.
I'm designing a preamp to adapt my dac output voltage (3V peak) to my ampli input (800mV) and introduce a volume controller.
I started from the Bruno Putzeys' article

https://www.hypex.nl/img/upload/doc/an_wp/WP_The_G_word.pdf

and from a through hole version realized by @alexcp

https://www.diyaudio.com/forums/analog-line-level/325268-balanced-volume-controller-line-stage.html

Respect to the second one I just added some bypass/decoupling caps near each opamp.
On the same board I would also add the power section and a relè for soft start.
Both projects use a solid ground plane, so I realized my PCB putting a ground plane on the bottom layer.
I noted that on the Bruno's original PCB he avoided to put the ground plane under the power filter caps. This is (as I understood) to avoid that caps charging current create noise into audio section.
So I realized another version of my PCB in which I reduced the ground plane area and connected it in a single point to the common rail of power section (please note that the power section is splitted in 2 parts, negative voltage on the left and positive on the right side).
Now I have some doubts about both results because (for routing reson) I have some power rails on the bottom layer, horizontally, and this seems to me like a break in the ground plane.

Even if I read a lot of articles/posts/comments I'm finally not able to solve my doubts.

1. Is my first version of PCB ok?
2. Is my second version better than first one?
3. Am I right about ground plane break? Do I need to do something else?

hey guys, looking for a killer 12 and 15, something in a ported enclosure that will shake the foundation of a house and still sound killer for music. looking for a 12 and 15 that will work in a smaller enclosure upto 3 cubic foot for each driver

thoughts, recommendations. will be using with a dayton dsp 1200 watt amps

I am looking into upgrading my low end and would like to have opinions if it is worth the effort to replace my present sub-woofer driver Scanspeak 26W/4558T00 to a 26W/8861T00 that I have relative cheap at hand. The driver is mounted in a 63 liter closed box made of 21mm MDF – see picture.

A more general part of my question is this: Will a dedicated woofer driver make less distortion than a sub woofer driver in the same box?

I have an active system with Uli Bruggeman linear phase filters.

Until recently I had a 3 way system with a “satellite” containing a Mundorf AMT tweeter and a 4” 12MU driver. During a listening session at a friend having high end Linn speakers I noticed that he had a better perspective in the upper bass region. Therefore I build a new “satellite” with an additional 5” 15MU bass/mid range driver. It works quite well. My XO is 200/900/3000.
I guess that a 6.5” driver would have blended better in, but i felt that the 5” gave some design freedom and a smaller cabinet.

I am looking forward to hearing you comments.

Br Erik

Hi,

I bought this board from another member here little more than a year ago. As he described it it was "blown up". I already have a Millet DCPP and though I'd get it and fix as a spare. I ordered the parts I thought I'd need from Mouser and there it sat. Well I'm not getting to it any time soon. Board is stuffed , missing some diodes and FETs. The coupling caps are Angela and they are probably worth more than I'm asking.
The board and the new parts listed on the attached invoice -$50 plus shipping.

Hi


I am working on this amp. It had 3 of the pre amp tubes(ECC83) dead. Upon checking, the bridge rectifier that provides the filament voltage has open. I replaced it as well as R133(470K) and R33(10 ohms) which are blown. Now when I turn on the power switch, after a few seconds there is sound. Strange because the standby switch is still in OFF position. I have checked the switch and it is OK. The voltage at W9 is at 460V, but the voltage at W10 (which connects to W8, the center tap of output transformer), with the standby OFF is at 380V. This 380V going to the OT is what causing sound at the speaker with the standy OFF. When I turn ON the standby switch, then the voltage at W10 goes up to 460V. However the sound is much softer and distorted. I have yet to check the bias and tube dissipation, which I will do tomorrow.


Thanks

Does anyone know if these are the same choke? I have a lot of stuff at Banzai that I want to order, but at Banzai it is not stated that it is suitable for Mesa Boogie.
I want to run the Deep Mod on my 50/50.
But since it is indicated on both sites that this choke would be suitable for the same Fender amplifiers, it seems the same to me.
I would like to hear your experiences.




Here is the link to Banzai:
Choke 90mA DC :: Chokes :: Transformers :: Passive Components :: Electronic Parts :: Banzai Music GmbH
And here the link to TAD:
TAD-Tubes, Verstarkerrohren, KT88, EL34, ECC83, 12AX7, Amp-Kits, PSVANE | Tube Amp Doctor Onlineshop.

do someone of you know the magnet system typology of external Woofer
is ferrite magnet or neodimium or alnico ?

thanks😉

Hi all,

I am looking for one or pair of 60-100uf 450V capacitor. TCC or other British Made capacitor is also fine.

Will pay for reasonable price. 🙂

Hello,
My name is Michael. Thanks in advance for all the help and your patience with all my questions. To better understand my options with a new speaker wall. I mainly listen to music but the TV will run on these also. I have a pretty good idea for everything but speaker placement. My home is being gutted and I have a chance to get the main wall set up. Floor stands aren't an option so custom in-wall/on-wall is what I'm thinking. I will post in design and build.

I'd like to drive each driver in my active 3-way speakers with an individual amp channel, preferably TPA3255.

So I could go for a 2-channel amp plus a single channel amp.
Or another option - I found this board:

Amplifier Board - AIYIMA B2D2205 - TPA3255 | 4 Channel 315W Power Ampl

A 4 channel TPA3255 amp.

I remember reading though that TPA's don't do well when an output isn't connected (?).

Would it be okay to use a 4 channel board like this for 3 channels, leaving one unconnected? Or would that cause problems?

Any other tips / hints on getting 3 TPA3255 channels working would be greatly appreciated as well.

Long story short.

DLS XM10 class AB mono.

Amp came in for repair. Goes right away in protect. Pin 10 on the SG3525 is at 5v. Grounded it. Power supply section works fine. OP amps voltages are fine at 14.8v. Rail voltages are present.

But the amp produces approximately almost full negative rail voltage at the + speaker output. If not grounding pin 10 of the SG3525 protection circuit kicks in.

I've pulled out all of output transistors and their drivers - all read fine over ~140 Hfe.

Q60, Q61, Q62 - reads over ~250Hfe, but the board has some marks from overheating on the bottom side. I see there are heatsinks location on the board, but the heatsinks are missing (oh cheap China) 😀

Q17, Q18, Q53 - have been changed with brand new ones

R167 - was out of tolerance - changed this one too.

I've checked each one of the transistors and there is no short anywhere. I can't find what causes the amp to DC offset so badly. Checked almost every resistor, diode and transistor and they all read accordingly.



Schematics are here:

http://www.tehnari.ru/attachments/f114/450443d1579809818-noaia-xm10.pdf

Last page is the exact one.