Hello all, I have several Crown K1 and K2 amps needing the 8200uf 110v capacitors in the output modules replaced. I am looking for a less expensive alternative than Crown factory parts. I see a 10,000uf 125v Chinese capacitor on ebay for about $9.00 but am very hesitant about performance and longevity. Does anyone have thoughts and maybe a good substitute? Thank you.

For the device under
SB12-NSD
– SVS
I need a schematic, because of the necessarily of enhancing the gain factor.
According the attached image of the plate amp there are follow PCB's:
1) input board (maybe summing amp, low pass crossover network and line buffer)
2) power amplifier board
3) main board (switch mode power supply)
Because the circuit boards are purchased parts from different far east manufacturers, SVS Sound doesn't have a detailed circuit diagram.
Who know the actually manufacturer of the input- and power amp board ?
Thank you for an advice.
This thread doesn't help:
SVS PB12 NSD driver substitute

I am building a 6C33C amp and plan to connect the heaters I'm series. My question is do I leave the center floating, ground it at chassis ground, or elevate?

I noticed something a bit curious when looking over the manuals for the (later) Aleph amps.

The Aleph 1.2 and 5 have the 4 ohm output at 1.5 times the 8 ohm output. But the Aleph 2 and 3 have it at twice the 8 ohm output. (The Aleph 4 manual does not specify a 4 ohm output. And, familiarly, all of then do poorly below 4 ohms, though the 3 is the only one that seems to specify a 2 ohm output.)

Is there a reason for this? To what extent would one expect it to make a difference when driving 4 ohm speakers? This does matter to me since (a) I have Dynaudio Contour 60s, nominally a 4 ohm load, and (b) I am about to take possession of a pair of Aleph 1.2s whereas my current amps are Aleph 2s (or VTL MB-185s).

Hello,
I've been trying to decide on a phono stage project since March. I've looked into most of the projects here, and considered most of the available kits on the market.

I'm at the point now where I just want to build from a schematic; there are too many PCB projects and kits to choose from.

I have some JAN 6922's (that I'm guessing will work here), and this schematic looks to be about as basic as they come.

I did find this thread, and I don't think anyone ever made PCB's, or not. But, that's fine. Coming up with point-to-point a layout shouldn't be too difficult.

There's even a power supply to go with it.

I plan to go ahead and order some parts soon.

Hello,
Is there a rule of thumb minimum distance (ratio of cone size) between the front and rear cabinet walls please. I am a novice cabinet designer and have just about got a grip on most of the params and in's n out's of sealed and ported boxes. But in all my research i have not found any guideline for minimum practical distance behind the driver.

Just looking at the situation i have the gut feeling that a system with the rear wall 1mm behind the magnet might not perform as well as a system that has more space behind the driver.

Many thanks in advance

Been looking at the McAlister audio stuff and wondered what people thought or think of his approach?
http://www.mcalisteraudio.com/

A nice review from stereomojo that got me interested http://stereomojo.com/McAlister review/McAlister_review.htm
Dave🙂

Hi I am searching for a conttol unit/ tuner for a Nak1200 mk2
Please get in touch if you have one or know someone who does. Im UK based but dont mind shipping from anywhere thanks

Anyone bored enough to help me redo my lame attempt of an Xover?
Concept:
Combine a pair of eight(ish) woofers (7.5 inches actually) from some old Fisher 2-Ways and some Dynaudios D-28 tweeters into a decent two-way project. I decided to save and use the Fisher woofers since the cones are made of a "foamed" metal of some sort and could yield interesting results. As for the tweeters I had a good old pair of Dynaudio D-28 available so...
why not.

Restraints:
- KISS keep It Simple
- First Order / SECOND ORDER might be better¿?
-Use what is already available. Compromise.

To make the story short, I have no experience and I must learn from the process. I replicated the original dimensions of the Fisher boxes to have some reference as for the original engineering (if any) since I don´t have spec sheets for the Fisher´s drivers or way to measure them and thus the project became so far a trial and error kind of thing.

I´m happy(ish) with the sound (being listening to them for some months now) but I know my progress with the xovers is a sum of uneducated guesses and lots of listening. Will be fun to see what improvements we get with a more formal approach.😀

The xover started with an online calculator selecting 1900Hz as start point using 1st order Solen Split that yielded a 7.4uF cap for tweeter and 0.65 mH inductor for the woofer. From that point on trial and error evolved to the attached imaged where I added a resistor in series to the original components. 😱

TBH it sounds good but I´m sure you guys can help me take this ship to a better place.

Please don´t toss me into the flames this is my first time with speaker guts really. I´m reading some stickys related and I´m learning as I type LOL.

Cheers from Mexico.

Rob.

Hi all,
I've been harvesting components from dead electronics, building up a box of goodies for the time when I'll need something to build my first x-over, or a BSC circuit, or whatever.
Today, I pulled apart a busted Samsung digital amp.
It had a bunch of these things in it. I assumed they were ferrite-shielded inductors.
I put one on my DATS V3 box, to see if I could get the value for it, and it says it's not an inductor.

Ok...so what is it then?


EDIT: I considered that maybe it was just faulty, since a direct measurement with my DMM returns about 0.6ohms, so I test all of them. Every one reads about the same; right around 0.5-0.7ohms.

Now I'm really confused... are they all equally shorted, or ???

I am playing with a MiniSharc board as a benchmark for my own DSP processor.

When a run SPDIF from my server to the Minisharc with no processing and back out to SPDIF to my DAC I think I hear a subtle degradation in sound, especially in vocals. I will confirm with a blind test as I am doing the switching myself but assuming this result holds, why?

1. Could it be jitter introduced in the Minisharc?
2. Is it the ASRC step from Redbook to 48Khz?
3. Is it my DAC (Denafrips AresII) is not as good with 48khz?

Is it all of the above?
Is any of the above?
Is the answer knowable?

Thanks, jd

I'm building a second iteration of my arrays that will only include 2 possible 4" drivers from Markaudio for a full 16 driver per side at 9 feet tall:
Alpair 7MS or
Pluvia 7HD

Each driver is in it's own sealed enclosure which is about .3cuft.
Each driver will be individually powered and have their own volume control.

Most array builders go cheap. That's not the intention here, price is not a consideration. I liked the sound and off axis response of the original Pluvia 7's but they are EOL, so I must choose from one of the 2 above.

ICEpower 500A Mk2
500W General Purpose B&O ICEpower Amplifier

I have a handful of these left over from a project.

£40 each including shipping within the UK (a little extra for EU)

Here is a link to the manual:
https://icepower.dk/download/2411/

Note you'll need a PSU (not to be confused with ASPs, although I think you can run one off a 500ASP)

So I've been semi-upgrading a pioneer SX-205. So far I've changed out all the 4558 op amps (ugh) and all the signal path capacitors with panasonic fc series ones. That's about it. Schematic here: http://diagramas.diagramasde.com/audio/PIONEER_SX205_SX255R.pdf

PSU caps are a no-go, size is impossible to find without downgrading the capacitance. Resistors would be a pain because when replacing the caps I found out the solder pads come off wayyyy to easily.

Any help is appreciated.

Almost a year ago someone (googlyone) told me to do a little reading and look into this stuff, that most of it is basic calculations. I took it to heart. Googlyone was right. I needed to look into it and most of it was basic. I read and skimmed through 6 or 7 books but by far the best one was Practical Electronics for Inventors, Fourth Edition by Paul Scherz and Simon Monk. One thing led to another… diyer. I’m not an expert nor did I use any formulas that are not already published. Please, if I have any blindspots or missed the mark somewhere, like googlyone, let me know gently.

The calculator: At it’s basic use you can see the impedance load you are putting on your DAC / Preamp when connected to multiple power amps. On the more advanced end you can use it to size a voltage divider to balance the output of Amps with different specs. (input impedance, gain, SE or balanced)

Thanks googlyone for the nudge I needed.


Impedance Calculator — STUDIOPHON

Is the USB interface to SHARC and ADAU processors the same device?

I saw this SHARC processor that includes a USBi "for SHARC" and I don't know if that's marketing or if the SHARCs require a different interface.

Link to SHARC DSP

Also shown for ADAU1452

Link to ADAU1452 DSP

In contrast to this USBi for ADAU 1401

Link to ADAU1401

Or is it a case of backward compatibility for the SHARC USBi?

I need to make a back panel for my Dynaco PAT-5 preamp that will accommodate 14 sets of Neutrik Stacked jacks. I am attempting to make my preamp balanced in & out. How can I get a steel panel made and drilled for this?

I'm selling my stash of vintage etc transistors, no idea of total, estimated 100 + Most are NOS, some pulls, but most NOS. Some came from a hifi shop shut down in 1987, some from parts collected over 20's years. Please don't ask me to list them all.


I'm asking £100. Will post most anywhere, UK/EU prefered.


Drop me a PM if interested, Andy.

Received my drivers, did a "rough" layout of cabinet material needed and have 2 4x8 sheets of Baltic birch ordered.
To do:
Decide on what veneer
Binding posts
Outriggers
Stuffing.
This will be a far easier baffle then I am used to as there is only one driver.
Really looking forward to getting into this groove again as it has been a while.
Thanks to you guys for providing me the opportunity and the information to be able to do this.

I have a factory Aleph 3 that I like very, very much.
I also have diy Aleph 2 monoblocks.
I recently noticed that the sound from the factory Aleph 3 is more relaxed than my diy Aleph 2's.

I am wondering if the differences I hear are due to differences in the design (of the Aleph 3 vs the Aleph 2) or due to the parts used (in the factory 3 vs my diy 2's).

It seems a good idea to first check if the difference is due to the design. Has anyone heard the FACTORY Aleph 3 as well as the FACTORY Aleph 2? Did the 3 sound more relaxed than the 2?

Did anyone who has ever built and modified an Aleph hear a difference with resect to perceived "relaxedness" of the sound when using other brands of circuit capacitors (not PSU capacitors) or 5W resistors? If so, what gave the most "relaxed" sound?

My 2's were built by a friend a long time ago and I do not know how well the mosfets were matched. What does an Aleph sound like if the Mosfets are not matched properly?

Please note I am not interested in ways to make a "better" Aleph 2. I like the sound of the factory Aleph 3 and am not interested in changing the first stage of my 2's using ZVP, Toshiba Jfet or other parts. I simply would like to know how relaxed an Aleph 2 can sound compared to the Aleph 3 that I like very, very much.

Thanks!

I need 2 pieces lm3875 chips if someone have originals on stock.I see some on ebay but this are all from China,so I dont trust this parts.Plese contact me if you have some originals.

As above. someone I know has a pair of unloaded superscoop cabinets going begging. I'm wondering whether the 15" faital driver would work in them (drivers I already have, but do appreciate I'd have to adapt the box to take a 15" instead of an 18"). I guess they perhaps wont go quite as low as the PD1850 but otherwise would there be any drawbacks?

I am looking for a TEAC VRSDS 10, non working. I need only the controll board, not the audio part and not the optical drive. Offers from Europe preferred (obviously).

The voltage in this amp rapidly varies from 410v-440v. The speaker cone moves as well. It works fine but something is not right. Any ideas would be appreciated.

WTB a quad of 6F8g or VT-99 tubes In working condition for a new project.

THANK YOU

I am building HT speakers with FR drivers for LCRS. For drivers I have narrowed down to the FaitalPRO 4FE35 30W, 8 ohms, 91dB. My AVR is rated 50W, THD 0.08%, 2channel driven @ 8 ohms.

These drivers are also available in 16 ohms. I was thinking of using two 16ohm drivers in parallel ( to get an impedance of 8 ohms ) for the LR speakers. I want to do this because when I listen to music in 2.1 configuration on the AVR I can use the maximum available 2 channel power/wattage of the AVR.

Question - Will doing this nullify the point source advantage of a single full range driver speaker because my fear is that the throw of the two closely places drivers on the speaker will interact acoustically and smear the stereo imaging for 2 channel stereo music ?

Which is the best?
Thanks,
Stefano

Do you think is a good match?

If so, how to arrange the internal microswitches and gain pot for best results?

Thanks.🙂

Long time ago I bought some Eminence coaxials and compression drivers including Beta 12CX/ASD1001 and Beta 10CX/APT50 combos. Since then I have been building various cabinets in ply and pine and trying to assemble crossovers for them until I last year decided to buy a pair of pre-assembled PXB2:2K5CX allegedly designed for these combos since my home made crossovers had serious issues and I got tired of having a unfinished project. Ive managed to put together one pair of monitors with 12CX/ASD1001 + PXB2:2K5CX which I am very happy with both the box and the sound. The Beta 10CX and APT50 are spares for future project, more about that later.

I am now curious to know if it is possible to improve the sound without drastic measures? The sound is large, warm, dynamic and for the most part just how I like it with a few exceptions. The midrange area around 2kHz is a bit muddy and uneven I am sure this is because A) the bass have ugly peaks around this area and should be crossed lower than 2,5kHz, and B) the HF driver doesn't really have much volume in this area and it is recommended to cut of at 2,5kHz, and possible C) some baffle resonance issues or other box problems.

Another problem is that the HF L-Pad in the crossover seems a bit too much given the higher sensitivity in the 12" compared to the 10" which I believe was the original aim for the crossover. Some of the highest frequencies seems at least a little bit missing but that may be the rolloff of the driver rather than the LPad.

I have read a lot of threads and see various options, changing crossover and HF drivers seems to be the most common solution and this is no problem for me as I want to use the ASD1001 and the PXB2:2K5CX on the 10" instead, and use the APT50 for another 3-way future project. Yes a lot of projects in my mind.

I have narroved it down to considering the following parts:

HF drivers:
Eminence PSD2002 106dB rec. xo. 1,2kHz
Eminence PSD2013 108dB rec. xo. 1,5kHz
JBL/Selenium D220Ti 109dB rec. xo.1,5kHz
PRV Audio D280Ti-S 109dB rec. xo.1,8kHz

Crossover parts:
Eminence PXB2:1K6 1,6kHz LF12/HF18 no l-pad
Eminence PX-LPAD variable-10dB

Are there other options I should consider?

I see the new KP3012CX 12" coax have a much smoother rolloff so that may also be an option but I feel then its a fully new project new box much higher cost etc.

Not shown: a jfet tester, and Singing Bush. (Too hot and humid this summer.)

All of this construction is due to that great solder from the Store, which makes soldering (and almost makes desoldering) a pleasure.

I hope the image is right-side up when you click on it. I don't really know how to work these computers. (It was so much easier in the slide-rule days.)

Hey,

I'm planning to retrofit a Nobsound G3 (TPA3116) into factory car stereo. The plan is to wire up the car stereo volume knob to the TPA3116.





My issue is that the TPA3116 uses a 6 pin 10k potentiometer, whereas the car stereo uses a 3 pin 10k potentiometer. How do I wire this?

Hi,

I recently acquired a Schiit SYS 49 volume control. I have a choice to purchase a phono preamp either with an attenuator or without it.

In case that I get the former, which attenuator or volume pot takes precedence, the one in the Schiit or the one in the head amp?

Cheers,

Hi all,

I have a Peavey Transformer 212 with an odd issue. After power up, I hear this "whooshing" noise (sounds like a steam train). See video here for details. The only things that seems to affect the sound are the delay switch and pots.

I pulled out the control boards (very interesting PCB layout!) and noticed that the delay level pot (I guess it's an encoder) was wobbly. See video here for details. Other than that, there were no visible issues that I could see; the boards look brand new.

Checking the schematic (see attached), it looks like the encoder in question is an ENC2425V 16mm 24 pulse vertical encoder w/o detents. I haven't been able to find this part via a websearch, so I emailed Peavey about it.

Anything else I should try to troubleshoot? I'd like to confirm this encoder is bad before replacing, but probing the pins with a DMM didn't really tell me anything (readings were jumpy, but so were the other encoders I probed).

Anyone have a SAE MK1B parts unit laying around? I am looking for an EQ board and an outer shell case. I am repairing one that has a bullet hole in the back. bought it this way. the main board and power supply survived, but the bullet hit the back of the chassis just below the speaker terminals and hit the back of the EQ board and destroyed 2 inductors and the backs of 2 slider pots.



Someone out there has a box of SAE parts laying around or a dead unit in bad shape that would be a good donor.




ZC

plate amp or other.
good sound quality a must.

for peerless XLS10 with passive radiator woofer, plenty of headroom required, for potential upgrade.



will be upgrading to stereo woofers eventually.
so dual channel options are good, or if you have two matching mono amps?


my absolute dream is the hypex FA502 (as this ticks all boxes plus more, but is maxing out my budget big time)

location Australia, and i can help with managing international shipping.

Hello
I have to sell Hypex fusion 3ways plate amp brand new.
price $430 plus shipping .

best

Anyone experienced with this amp? Thanks

https://flic.kr/p/2jK1JKK

it is handy to build amp with these Wiha tools
HEX 1.5 MM screw driver
Hex 5.5mm or 6mm Nut Driver

I cant choose between the two variants of the ND-90 for my boombox project.

I like the response of the 8ohm one much better than the 4 ohm one ( both are in a 4 liter box with a port tuned at 63hz). I know that this is just another sprite build, but given the fact that i am going to power them with a battery pack(21v 5s 70wh) -therefore i need that efficiency- I am concerned about the battery drain in conjunction with the baffle step circuit the sensitivity of both the drivers in going to drop really low (bsc for 4ohm is a 6ohm resistor parallel with 0.4mh inductor and a 8.2 mF cap, not sure why he uses a cap in a bsc/ 8ohm a 20ohm resistor with a 0.9mh inductor). The efficiency of the drivers drops a lot especially when placed in a box.

Which one would you choose for the bass the volume and the battery endurance?

p.s i am guessign the max wattage i would drive them would be like 5watts maybe 10 if i want to annoy everyone around.

Hello to fellow members,

I've been only reading for a while but it's my first time writing something. I really admire all your work thus come seeking for help.

I have a Primare A30.2 amp and was looking for a way to convert the voltage from 120V/60hz to 220V/60hz. I looked into the schematics but honestly have no idea how to read it. If it's a simple jumper tweaking, I thought I could do it myself so I was wondering if anyone could shed some light before I take it to a dealer and spend $$$.

Thanks.

John

Today I applied power to this Hammond tranny. I was a bit surprised at what happened. To me, this looks like a typical dual winding primary and secondary tranny. Based on the diagram, you would think you can simple wire the 2-sets of primary terminals in parallel to get the resulting 28VAC on each secondary.

The 1st image shows the schematic with 2 separate and independent windings. To test it I wired pins 2 & 3 together and pins 1 & 4 together and then connected to 115VAC. Now, I know it's been over 50yrs since I had basic transformer theory (I was never in the industry though), but there must be a critical part of the theory I'm clearly missing, despite having successfully wired lots of trannies over the past 10yrs without issue in my DIY audio projects.

After, about 45secs I began to smell something 'off' and immediately pulled the plug. The primary side (without any load on secondary), was too hot to touch! I never got around to measuring the voltage on the secondary.

So, I pulled the Hammond datasheet for this particular tranny and found that their wiring diagram (2nd image below) was different then the way I had wired it. Still both in parallel though. I don't understand why, the way I wired it, caused the overheating, unless it was a phase related issue. Would someone be so kind to remind me of why this happened and the proper way to wire primaries in parallel. It seems clear to me the windings on this transformer are completely independent of each other, except for the core. Could the tranny be defective?

I have a Topping D90 external DAC which accepts SPDIF, USB, I2S, & AES digital. The latter is what I have using my old cdp as a transport. However CDs only go so far.

Without breaking the bank, i'm looking from a dedicated non-PC / laptop based, stand alone 'digital front end' where I can plug a USB flash drive or it may have it's own internal hard drive. It should have a basic menu so I can scroll around the folders and choose what files to play.

Connectivity, it seems USB is most common but i'm not a big fan of USB and uncertain if it's reliable as I2S or other dedicated formats.

Also digital front end should support DSD SACD, FLAC, WAV, MP3, the usual etc.

I'm not having much luck searching online and it seems most units are comprehensive having builtin DAC, amplifier, etc. which I don't need. I suppose in this day of age, people rely on their hand held smartphones and do BT streaming but i'm old fashion. I want simple plug N play, direct access. 😕

I'm wanting to build some dual subs for my system before the end of the year on as low of budget as I can manage given my needs, namely that I'd like between 110 and 115b of output at 20hz-90hz if possible, and that the dimensions not exceed 20in wide * 20in deep * 78.7in height.

I'm fully on board with using DSP to get there and smooth any troublesome peaks.

The design most appealing to me currently is the VBSS given a low cost of ~100 for drivers + 100 in materials per sub, however the inuke amplification required could potentially bring the cost up to 600USD... farther than I'd like to go if I can help it.

I currently have about 16 channels of 220W @ 8ohm amplification thanks to two ATI built Crestron CNAMPX-16X60s. Very clean, low distortion power. Given that I won't be most of those channels any time soon, I'm wondering if I could use that power to drive subs instead, and save money on having to buy yet more amplifiers?

I know some designs like tapped horns can get you more output for your watt... would that be a possible option? I know there would be some crazy peaks in the xover region, but I imagine those could be deal with via DSP. Dual voice coil driver could also be a way of getting more of my amplifier's power to the driver?

The Eminence 20Hz Tapped Horn – Volvotreter Homepage <- This horn seems like it'd check most of my boxes, but at 240cm it's slightly too tall (200 is more my limit), and the drivers listed are pricier than I'd prefer (would like to try and keep it to 100 per driver).

Currently trying to educate myself on hornresp but I've a lot of learning to do. In the mean time, any advice y'all have would be greatly appreciated!

for sale Holton soft start boards, i have one BNIB and one barely used.

70$ shipped for used.
100$ shipped for BNIB.

payment via Paypal.

I have many Motronix MRF-400H mosfet amplifiers (Approx 30pcs!) in stock (Barely used).
a few of them with Nichicon caps installed, all of them are in perfect working condition.

Price for matched pair: 30$ (BNIB on eBay 40$+15$ shipping for each!)
Worldwide shipping: 12$. (4 pairs or more, free shipping!)
Paypal fees on me 🙂


Specifications:
RMS continuous power:
150 Watts driven into a 4Ω load (tested with 2X40V DC Power Supply)
85 Watts driven into a 8Ω load (tested with 2X40V DC Power Supply)
0.03% Total Harmonic Distortion (THD+N)
Load: 4-8Ω (*** Can work with 2Ω load when use 2X30V DC Power supply)
Signal-to-Noise Ratio: >100dB A-weighted
Frequency Response: 20Hz to 20kHz ±0.5dB
Bandwidth: 20Hz to 100kHz ±3dB
Damping Factor: >200 @ 4Ω
Slew Rate: 30 Volts/ ms
IM Distortion: <0.05% (IHF)
Input Impedance: 20k ohm

After building a set of Pensils a few years ago I fancy trying my drivers in another enclosure.
Does anyone have a plan I can follow?

Thanks

Cleaning out my project bins and have the following unpopulated/bare boards for sale:

1. (2) MyRef RevC monoblock boards. These are the v1.3 boards that I ordered from Siva (linuxguru). See the pics in the following post: https://www.diyaudio.com/forums/chip-amps/167458-myrefc-build-guide-post2844341.html. I will include copies of the schematic and board layout that I received with the kit. $15+shipping for the pair.

2. An early (2008) VSPS (Very Simple Phono Stage) board from RJM. See the following thread for more info: https://www.diyaudio.com/forums/analogue-source/33555-diy-phono-preamp-cheap-simple.html. I will include a copy of the original BOM. $5+shipping.

PM me if you have questions. Thanks!

-bill

This is my first working tube amp. I pulled it from a old readers digest portable record player. I built a dim bulb tester and recapped it before hooking it up to my pioneer bs22 speakers. Wow am i impressed!!
Anyway...now what? Id love to remove the tone controls. And maybe improve the circuit somehow. But, i also want to keep it simple...
Thanks in advance

Amp powers up but no output .

I was checking for regulated voltages and on 1 opamp I bet the following voltages

NJM4556

Pin 1:21.35
Pin 2:12.79
Pin 3:12.79
Pin 4:12.62
Pin 5:0.02
Pin 6:12.64
Pin 7:12.78
Pin 8:12.78
Pin 9:21.53

Is this normal for these amps?

Hi!

Just for fun, a small test of three DAC's.

Denon DCD 1290
DCX2496, rca modded
OpenDRC-DA8

Source: CD 16/44.1 original record with a crowdy mix.
Target: Motu Ultralite ~600$ sound card (24/44.1 capture)

I will share the labels of the tracks tomorrow.
...Can not upload atm.

While rummaging through my wood pile, I ran into some zebra wood scraps that I thought might look cool around my AT-LP120XUSB. Spruces it up a bit. 🙂

For now they're just tacked in place on three sides with some hot glue. I plan to dampen the underside of the plinth with Plasticine sometime....when I do that I'll trim them up and fit them a little better, and re-fasten them a bit more securely, tho I'm not sure I want to mount them permanently yet.

As stated I purchased the ebay kit as seen on them here and there with the new PC boards and the like. So, Have only recapped the Hafler DH110 with success I then though to take this on. Long story short. I felt pretty good about my soldering job on it with no cold solders that I am aware of. It power on with a variac and have it up to 110. No fuses blown. Great. Get speakers on it and nothing. Not even fuzz sound. Wiggle the rca's and no sounds as well as speaker wires to hear that cracking sound when you hook them up. Just nothing. So, not knowing how to back track diag. Could someone walk my through what to check first and then the next to see what I hooked up wrong. Was working on old board and wires before.

Just to have full info.. I also rewired the entire amp as well and thought I followed the instructions to the letter.

Can get pics up if needed. Thank you for any help to this noob trying to be a one of this idiots to take these things on.

I do have a Fluke Multimeter if I could also know what setting to be on to check different parts of the amp out to diag my issue.

Geez, what a noob...

Does anyone have a frequency response plot for the KEF T27 tweeter? The only plot I can find online includes a third order high
pass filter, but I want the response of the raw driver.

Has anyone 2pcs of the LTC6228IS6#TRMPBF and would like to sell me them?
Currently ordering parts for a new project and that are the only two parts I can't get...

National Instrument has made a "community edition" of LabVIEW 2020 available for free. You need to create an account (of course) and redo the license after a year; it's a fully functional "test and measurement" program development environment that works with GPIB, Serial and other USB connected hardware. Pretty good.

Regarding Audio test, there's not much you'll be able to do with it that hasnt been thought of and done already - considering the myriad of available audio test programs available in the last 20 years...

What you can do with it is create something specific to a particular need, that other general test system programmers wouldnt have possibly thought of -

Something like "When I clap my hands, give me a spectrum analysis of the sound I'm measuring in the moment just before the clap".

I'd be interested if anyone here installs and uses the LabVIEW "community edition" for audio test and measurement -

Hello. I Thought in a project at the begining of this year with SB Acoustic drivers. I wanted a 3 way floorstander with the following config:

Tweeter: SB29SDAC-C000-4
Midrange: SATORI MW16P-8
Woofer: SATORI WO24P-8

I thought in a active system although I have changed my mind and would go for passive... or selling the drivers because I do not have much time not space for this nice project.

Does any one of you has any suitable crossover suggestion for this config?

Thank you

I have a Behringer nu6000dsp that gives a hellacious power-off thump when switched off by my smart power strip.

I want to use a relay at the speaker outputs that will open before the power is removed, which I can achieve with the delayed output on a surge protector I have.

I've perused many threads on relays and it sounds like mechanical ones are problematic because I'll never be switching with a load to keep the contacts cleans.

The possible issue with a SS relay is linearity at low levels.

I'm thinking it's probably not an issue with subwoofer frequencies but wanted to check with the more knowledgeable.

Would this one be suitable?

Solid State Relay 25A | RSS Solid State | Solid State Relays | Relays & Timers | USA

Key Features
Current ratings up to 90A at 660VAC
AC (90-280V) or DC (4-32V) input
Input current regulated 10mA
Photo isolation of input and output (up to 4000V)
Zero voltage turn on
Dual SCR output with built-in snubber
Optional fingersafe cover
Worldwide approvals: UL
C-UL
TUV
CE
LED status indicator standard
Updated pressure plate for easier installation of wires
New housing design keeps wires from twisting and breaking
Dual SCR output with epoxy free design

I bought these supposedly 30v zener diodes.could anyone confirm that they are as such?Never saw such notation.


PS.They are indeed...just measured them, but i couldn't find a 40v supply at hand before writing this topic..As i can't delete it anymore...

hi,
i have this Parmeko oil-filled transformer,
and i dont understand the primary windings description?
it's quite clear the secondaries are 200-150-0-150-200
but the primary is a bit confusing 0.5.90.115 ???
how do i connect for 230vac operation?
and what does this 400c/s stand for?
please help me to understand it.
best and thank you.
K

I have acquired an amp which uses two ILP HY248 modules and a single ILP power supply.

When I turn it on I get ~10v across the outputs, but only if there is a load/speaker attached. If there is nothing attached there is no voltage and no voltage appears if a load/speaker is subsequently attached.

If, however, I start to put in a signal, one of the modules develops a DC voltage and one does not.

Any ideas how to fix this? Given that they are modules there is not much I can fiddle with. Can both be broken in the same way?

Many thanks,

Simon.

I just made a pair of XKi’s with PA130s in them. I am powering them with a Behringer iNuke1000dsp. I mounted them under the eaves of the side of my garage for some backyard sound and for movies when I bring a projector out. I watched a movie last night. Wow!!! I am so happy with these. The bottom is so beefy for the size of these!!! I’m not nearly as eloquent in my description but everything just sounds so well balanced. I did some tweaking with pink noise(though not really cuz I just used my iPhone mic) and a sine wave sweep.
Thank you so much to whoever has designed/shared plans!!

After much reading i have built Troels Gravesens Fusion BAD. (pic attached) Why, because he seems to go into every detail and explanation and builds for big companies as well and then gives out free build information. i liked that style.
I think they are great, i think he has done a great job and service, i am listening now, everyone else who has listened says how "out of the box" the sound is, its dynamic, realistic, great bass etc etc.
Its the best sound i have ever heard, but i accept completely there is better to be had, even Troels' own more advanced designs, probably much of what all you guys build.
I have also now read lots more since i built these.
I have done quite a lot to the room, that has helped a lot as well.
I am not dissatisfied at all, more curious, everyone says Open Baffle blow boxes away, so, if i used exactly the same hardware on an open baffle would it be interesting and good, or a waste of time and effort. the baffle could be the same dimensions, i can use the passive crossover i already built for mid/treble and even adjust the bass if necessary as the design has DSP plate amps on the bass....
It may just be that lockdown causes this curiosity, is it worth a project or a waste of time!?
thanks mike

This is more a thought experiment, I have built a couple of 3 way speakers with passive crossovers. I think about making them active, but I hit the same wall, price. For a 3.5 way setup I would need 8 channels of amplification. I think class D would work for me, but every option I look into, new power amps, kits, raw amp boards, Hypex plates or used multi-room amplifiers it always ends up costing $1,200.00 USD or more. Then I need to add a 2 in and 8 out DSP like the Aurora and I stop thinking and stick with my roughly $300.00 3 way passive crossovers. Am I missing something or is active still just expensive?

Hi
My ML Purity has stopped working, and I suspect that it is due to a
failure in the Class-D amp. (the panel works fine).
So, does anyone has a schematic for this Amp?
Br,
Brian

I have here a output transformer with ul taps and lots of 6v6 tubes.

I don't like 6v6 in a harmonica amp, too bright. but looking at building a guitar amp to use some of the parts I have on hand.

if anyone has tryed ul on the 6v6's push pull how did they sound.

preamp will probably be 5e5 but using Russian 6h9c

This is all just an idea @ the moment

I'm having trouble with my Sony CDP-333ESD which has a Sony BU-1 laser assembly.

I have just replaced the original BU1-E laser with a compatible second-hand used BU-1C.

The good news is that after installing the replacement laser it reads and plays around half of my CD's flawlessly from start to finish. The bad news is that with the rest it will not even read the TOC.

If I load a disc that it 'doesn't like' it will not even spin the disc which suggests to me that it is not detecting a reflective surface from the disc. Is that correct?

So does this mean that the photo detector system is somehow defective? Or could it be that the laser power is just a bit low (because of normal laser aging) and that this only manifests itself as an issue on discs with lower than average reflectivity?

It is very frustrating because it sounds great when playing discs it can read!

Looking for a FR driver that performs well between 100Hz - 20KHz in sealed or circular ported enclosures for LCRS speakers that will be crossed between 100-120Hz.

Goal - To use the advantage of the point source accuracy of the sound from a full range driver to build a 5.1 speaker set up for movies and music spanning genres like soft rock, dance and pop mainly. For the general sound quality benchmark, lets use the Marantz NR1510 AVR as a reference.

AVR Power Output - 8 ohm, THD - 0.08%, 2ch Drive - 50W

Current top contender - FaitalPRO 4FE35.
Reason - 8 ohms, 30W, 90Hz - 20KHz, 91dB, has good reviews and the amazing price of £13.73(Vat incl)/driver .

Question
Is a driver that has 100Hz - 20KHz range enough since HPF will be applied on LCRS speakers at 120Hz on the AVR or do I need a driver that goes lower?

Would appreciate other driver recommendations. Can go for higher priced drivers if I can get appreciably better sound quality.

PS: My earlier find was Tang Band W5-2143(£65/-) which I now feel is over kill for this project in term of its frequency range or should I stick to it for its sound quality.

This interesting article as well as recent discussions have made me think again about how I test the speakers that I am experimenting with, and also evaulating the entire sound reproduction system.

I do not have the sensitive instruments to test my speakers, no an anechoic chamber, but this may be beside the point. I have been, after all, listening to music and testing what I hear 'subjectively'.

I have come up with some working guidelines to evaluate audio systems by ear only:

• Frequency range - do I hear the lowest frequency and highest frequency instruments?
  
• Clarity - Can I hear all the instruments playing all the time clearly. If it is a familiar track, can I hear what I hear with headphones and do I hear any detail I had not heard before?
  
• Can I hear what seems to be distortion?
  
• Are the percussion sounds sharp and clearly defined or sort or muffled and woolly?
  
• Do I hear any unnatural (to me) colorations of sound- boxiness, sizzling sounds from the tweeters?
  
• Do the music and vocals sound natural?

There are only a few high powered systems and headphones that will pass fare well in the above set of tests, so it is kind of a basic hi fi filter.

Anything more to add? It seems a good way to do things.

Confusions about the options and possibilities how to combine the BPBP with the Maya remote control, made me decide to start this thread, where all info being scattered over several threads now combined in one place.

Intro
A preamp without a remote control, in particular for controlling the volume, is only half a preamp.
The BPBP is a superb preamp, with a solid circuit design, but most special is the absolute excellent PCB design that makes it stand op top what is possible today.
The circuit design itself was used almost exactly by Mark Levinson (and probably by many others also) over the last 10 years for all their models of Pre-amps, with the difference that they use Fet switches in a linear R-2R network for volume control, where the BPBP uses a standard linear Pot.
A pot can be remote controlled by using a motorized version, with added hardware, but more elegantly is to control the volume digitally.
Fet’s as being used by ML cannot compete with Relays in behaving like ideal switches and also a linear R-2R network is way more complex in # of components and in steering without having any advantage over a logarithmic attenuator, so the choice how to replace the pot was easy to make.

Realisation
In controlling those relays, a remote control is needed, and my attention was caught by the well-designed MAYA remote controller, having lots of options, like Bluetooth and a learning IR remote control, 64 steps to control the volume in 1dB steps, multi-channel select and last but not least a serious display giving lots of information.

A complete Maya system must be seen as a “passive” preamp where the signal comes in, gets attenuated passively via a logarithmic relay switched attenuator and leaves the system without any amplification in between.
As such, Maya is doing a great job.
The BPBP however is an active system with a very high CMRR and dynamic range, where volume control is integrated in the feedback of an Op-Amp.
As good as passive preamps may be, the top of the preamps is reserved for active preamps when looking at test magazines like for instance Stereophile.
An interesting feature is that hardly any high end preamp has a tone control, which is also not available on the BPBP.

There are however some potential restrictions like only having 2 input channels.
For this reason a 6 channel GB was started on this Forum.
Another restriction is, that the BPBP is in its basic form has no provision for a remote control.
To solve this problem, a Volume Control Board (VolCB)* was developed giving the possibility to have 64 steps of 1dB each, to being steered by the same Maya controller that also controls the passive Maya preamp.
And here it is where things are beginning to become complicated.
There are three different boards start with: the BPBP pre-amp, the Volume Control Board that replaces the stereo pot and the Maya controller.
This volume control board (VolCB) can select via the Maya remote control between the 2 channels that are available on the BPBP preamp.
If you wanted more channels at your disposal, there was the 6 channel GB board that is operated manually, but no longer available.
With a new GB PCB would it be possible to select 4 or maybe even 6 channels from a similar external input/output board directly from the existing Volume Control board, because the control hardware is already there.
If someone can give me all the essentials of the 6 input GB, I could make a redesign directly to be controlled from the VCB. Maybe 4 balanced inputs should be enough for most situations?
It would be also nice to add a balanced record output to this external board.

Do not confuse these multi-channel options with the multi-channel boards that Maya supplies for a complete system, because they cannot be used for the purpose of selecting input channels in combination with the BPBP.
In case you are happy with a passive preamp, I think the full Maya system will be an excellent choice with the option to have multiples of 4 input channels either Single Ended or Balanced.
When you want to go for the top in high end active preamps, take the BPBP.
However using the full Maya system with all its features like having many input channels IN FRONT of the BPBP, thus placing two preamps in cascade makes no sense at all and should not even be considered.

To conclude for Stereo Applications:

1) use either the full Maya system with expandable multi-channel inputs, or
2) The BPBP with standard 2 input channels to start with, combined with the Volume Control Board and the Maya controller subset, as in this diagram or (later)



3) The BPBP with an added multi-channel board (still to be designed) with 4 or 6 balanced input channels to choose from and also equipped with a balanced record output, again combined with the standard Volume Control Board and the Maya controller subset.


* Until now this board was called the “Hans” PCB, but I suggest changing this name from now on in VolCB.

Maybe all MP3 players ?
Is there a limit to the number of ( mp3 ) files that can be on 1 usb stick ?
Or number of bytes ? ... Or ?
I made a compilation of albums for my friend ,
and the titles ( at least some of them ) show on his screen ,
but the stick does not play .

I've seen some references to the idea that a bipole driver configuration can eliminate baffle step effects. I'm not seeing it.

Any driver putting out long-wavelength frequencies (compared to box dimensions) is going to radiate into 4*pi steradians. Put two drivers on the front of a box, and both are going to "creep" around in the lower frequencies and drive the whole hemisphere. Put one on the front and one on the back, and both are going to do the same thing.

Am I misunderstanding the argument or is it not grounded in reality? At the end of the day, it shouldn't matter where you place a driver if the wavelengths it is sourcing are large compared to the box (baffle) dimensions.

So you've built a diy amp, it tests ok with a restive dummy load but when you plug it into a test speaker it shows signs of instability, how do you personally go about testing and then making the amp stable?

So far I've only found two references online to the method, the best being this one by Patrick Turner - amplifier-frequency-tests I looked in the Tek Cookbook and in Metzler - nada. There is obviously some info in Radio Designers but for those who aren't big on theory it can be a bit opaque. After having read Patricks article there's a few things I'm unsure of but AFAIK the procedure is this.

With the amp in open loop and closed loop and with various capacitive loads do frequency sweeps looking for where THD is greater than 2% or where the OP of an amp peaks.

So for instance I ran several sweeps yesterday with my recent 807 PPP amp with a 100n and then a 470n as load, noting down where THD exceeded 2%, no peaks were noted or increase in THD.

I then ran a sweep with my big test speaker which is a cobbled together job of a 15" Celestion woofer cab, 10in Celestion in another cab, and two Fane horns in another cab, all through a Kef Xover, this typically is a difficult load. I got more clear results where THD shot up to 80% at 15hz and at 45khz and again at 111khz, this was using a HP3903B to monitor the OP as well as a B&K AC voltmeter, signal source an Advance Type 81A.

I'll run some more but would be very interested in other builders methods, I'm after practical methods rather than maths heavy methods involving bode plots, Nyquist diagrams and imaginary numbers please. I'll probably change the odd coupling cap and fit a few step networks as well as a zobel network to reduce gain at HF but interested in other members wrinkles.

Andy.

Hi everyone!

It seems that recently I made a major discovery for which, I think, I should be given a Nobel prize. 😉
What I did was I switched off an active crossover in the subwoofer amplifier and put a large and thick pillow near a woofer. Thus the woofer is used as a full range speaker without any crossover but the woofer in the sub is closed or muffled by a pillow and hence I hear only bass up to may be 100Hz. I was amazed by the quality of bass in this set up which does not cost anything.
You just need a good woofer, a cheap amplifier and a pillow or a blanket. And that is all: no crossover is required and a pillow is used instead of crossover. The bass is fast and pleasant to listen to. Isn’t that wonderful?

As regards the fact that some people might think that in this setup the sound coming from the sub can be easily localized that is not the case.
I have installed my sub near the right speaker to the right of the speaker. If 100 to 200 Hz were coming out of the sub then I could easily hear the sound coming from the right speaker. But I do not hear any sound coming from the right. All I hear is just deep bass.
So this means that a pillow muffles sound very efficiently indeed.
I wonder if anyone has heard of this method before?

Selling my stash of TDA1541A DAC chips

All tested in various diy projects

marking explainations here: Philips TDA1541A d/a converter information - DutchAudioClassics.nl

TDA1541A - S2 100 euro

The others 40 euro combined

Shipping at cost

Hello,

I am trundling right along with my Neurochrome LM3886DR amp build, and I am at the point where I need to start wiring things together.

(red and black wires sort of mock up the input signal path)



What is the prefered method of wiring single ended inputs to an amplifier board?

The two options are, Mogami 2330 shielded microphone cable or plain 'ole twisted solid core 22g wire.



Shielded is a little more difficult to wire up, but is "supposed" to be better. (don't be too critical of the ends on the wire in the photo, I was just playing around, I know the ferrule should be pushed up to the insulator of the centre wire)

Twisted 22g solid core wire is super easy to deal with for soldering and "stays put" when bent where it needs to go.

Like most things I do, I am sure I am overthinking this, and either solution would be fine as I have seen both examples used. I am also pretty sure I would not hear a difference, but I would like to use "best practice" even if I won't notice the difference.

Thoughts on one vs. the other?

(I did lots of reading on this forum about this topic as well as general Google searched and I am still on the fence)

Thank you,

David.

I am looking to venture more towards a 300B dual tube per channel integrated amp for its sound preference and lower plate voltage. This dream machine might weight a ton after its done but that's fine. If I can get some suggestions with a rock solid simple design circuit with an excellent set of transformers that would be great. Integrated amp is always my personal preference. A dual tube mono block can be a last option. I saved up a handful of preamp, rectifiers and 300b power tubes. Any takes or suggestions will help be great.

Hey guys,

I've recently thrown a KAB-BE battery board onto my build with KAB-250v3, although since it's run out of power I haven't had any luck charging it.

It recommends a 19V 1.5A power supply to charge it, the closest thing I could find is a 1.66A. Regardless, Ive tried to charg overnight and I still don't have any power.

Any ideas what could be wrong?

My only hypothesis is that you're meant to connect a charging cable directly to the battery, although the only wiring setup I could find similar to mine had power go into the amp.

Thank you!

Why do my active speakers sound better with my PC as a source compared to a Denon AVR-E300?

PC motherboard is a Gigabyte G-Z170N-Gaming 5. Line out from the PC is a 3.5mm to RCA breakout cable. The RCA ends plug into a Dayton Audio DSP-408. Speaker wires run from DSP-408 to active speakers. (JBL 305P MkII, also tested with a DIY set of active speakers.) With this setup the speakers sound fantastic.

However, if I use my Denon AVR-E300 the active speakers -- both sets -- sound terrible. Attaching passive speakers to the AVR-E300 sounds much better, but not even close to the quality of the PC to active speaker combo.

As an alternative to the Gigabyte motherboard I have also used a Topping E30 to bypass the motherboard DAC through a USB connection. I did not notice a difference between running active speakers on either the PC motherboard or the dedicated DAC. Sounds the same to my ear.

Does anyone know why a PC motherboard would sound so good and an AVR would sound bad with active speakers?