Have 2 pairs for sale. Each pair comes with the optional remote and touch panel.

Totalling $660+ in retail, I'd like USD350 per pair excluding shipping and paypal fees.

Do note they ship out from Singapore.

More info here
https://www.madisoundspeakerstore.c...sp-active-2-way-amplifier-with-digital-input/
https://www.madisoundspeakerstore.com/hypex-amplifiers/hypex-touchpad-for-as2.100-amplifiers/
https://www.madisoundspeakerstore.com/hypex-amplifiers/hypex-remote-control-for-as2.100/

Looking for a matched set (4 pcs) for Diyaudio's 2016 Sony VFET kit, pls pm your offers thanks 🙂

I purchased 320 Phono and EB906/255 super shunt regulator from Erno Borbely a few years ago. Last year, I changed the regulator to Dexa and put aside the 255. Recently, I wish to use it again for another diy kit but I could not find the 255 circuit diagram again. The new diy kit uses only 20mA that the current setting at 240mA would make the power transistor red hot.

I remember there is a formula to calculate the resistor value but I can't find it. Can anyone give me the formula, or the value for 30mA or Erno's email addres (I wonder if he still reply email today).

I need to fill the gap between my sealed subs and midrange horns.
60-300hz would be the range I need with smooth top end roll off.
The 60hz horn is big (long) and I am considering other loading option that are the next best where high efficiency and low distortion is priority.

Here's a plan but not sure if it's good for my range -- anyone know this?


My 2nd find:
horn loaded 7th order banspass:
www.renkusheinz-sound.ru/pdf_datasheets/CE3TLOK_data.PDF

Would appreciate any recommendations from someone who has heard good midbass horns and experience other (close 2nd) loadings....
thanks
Herman

Hello

I'm hesitate between those two line preamp circuits, both are old diy circuit done years ago that I have just modified with Ltspice.

Any suggestions, ideas ?

Thank

Bye

Gaetan

Can a ballast tube be used as a CCS in an amp, say rather than a SS CCS used on the plate rather than a choke or a resistor? Maybe as a Cathode bias? There seems to be a large list of available tubes, although finding one to meet an exact requirement would likely be difficult. What would be the result it using one if it can be used. These were kind of the LEDs of the day? I have never seen such a thing, but ......

So we got our subs 20-90hz
And we got our kick bins 90-400hz (could cut down to 200-250 but they are flat to 400hz)


Obviously I'd want to use a horn for my highs somewhere between 1.8k-6k depending on the mid cabinet/driver used...

So what are people using for their mid bins?

Ideally I was thinking about hanging some multi-cell horn paths like some altecs or something..... But this means I would need some kind of mid bin in order to fill that gap between the kicks and the horn.

Anyone ever hear of any designs like this?

Or any suggestions for build types to optimize output of 400hz+ up to say 2khz?

Hello, I am repairing this Hifonics bx1000D it came with problems in the output. Does anyone know if the 10uf 250v capacitors that go on C19C C20C are polarized or not?

I've been using my "Brute Force" mu follower amp for headphones for many years but I needed something that could drive lower impedance headphones. I found the Glassware schematic for the Aikido/WCF amp online so I decided to build it point-to-point. I've got it working now, it sounds great with my Grados. It uses the same (6SN7/6BX7) tubes as the old amp and I've configured it for 32 ohm operation.
But since it's optimized for 32 ohms, what happens if I plug in higher impedances? I have 4 headphones ranging from 32 to 320 ohms and I'd like to use them all.

Hi All,

I haven't set up a TT in ages, and I'm sure that when I did it - it wasn't properly done. Establishing myself as a noob that just barely knows the terms surrounding TTs and components. 😀

Onto it...

My brother has a Denon DP3000 table with a Grace 707 arm and an as-yet unidentified cartridge / stylus.

He's the 2nd owner and has had it for 30ish years. He thinks he got it in 89.

Lately, he's said that it just doesn't sound quite "right". I'm hoping I can help him out a bit. He's gone to a local person (purportedly familiar with the arm etc.) to have the relevant physical settings adjusted.

No particular improvement to his ears. However, the person doing the alignment etc. (to the best of my knowledge) did not check the stylus or cartridge condition. I also don't know if the phono stage was ever set up properly for the cartridge. However, I assume it was. The sound was marvelous years ago to my ears.

Set up -

Stylus and Cartridge - Unidentified. Pics attached.
Arm - Grace 707
Table - Denon DP3000
Phono Stage - Forte FP 1
Pre - Forte 44
Amp - Forte 4
Speakers - Vandersteen 2C

First - could anyone help in identifying the cartridge? I tried to get a look at the back and bottom to no avail. I did not see any markings. Since he just paid to have it all re-done, I'd hate to loosen it and take it off.

Second - Any advice re: simple places to look and/or check to see if the stylus / cartridge is performing "properly"? I read an article re: stylus wear. That may require a more skilled person for evaluation than I. It plays music, but I do agree after all these years that some of the "life" has gone out of the music. With CDs etc. and other sources, the chain is just fine. So, I'm narrowing the search down to components directly related to the turntable / phono stage.

Third - Do phono pres potentially need any loving care? I had the power amplifier re-capped about 6 or 7 years ago due to an electrolytic failure.

I'd truly appreciate any insight. It's a lovely system, but the record collection is collecting dust at the moment.

After looking around it seems like connecting two Bluetooth speaker to one source and have them play stereo is a problem and not common.
Just connecting two speakers (booth playing the same) seems to be not always possible?

I found this old article: Tempow turns your dumb Bluetooth speakers into a connected sound system – TechCrunch
And i was on that Tempow site: Tempow | Enabling the next generation of Bluetooth Audio

Looks like some proprietary stuff that needs to be build into the device.
Not just software you can use everywhere...

I did see there are speakers out there that can do it. But you always need special software from that company and it does not work with all there speakers.

I wonder why its so complicated. I mean Bluetooth headphones play stereo - or not?

I have here 2 First One amplifier modules v 1.2. If you look closely at the photos you'll see one of the capacitors has a bulging top. I did something during set up and I would only be guessing if I listed a reason for this. I just don't remember. I just ordered 2 more modules from "lazy Cat" and finished the amp.

So 1 module is good, basically unused the other consider not working.

$50 plus shipping.

I have a sundown scv6000d that had several mosfets blown in the power supply. Replaced all bad parts and I have the amp up and running, but one of the banks in the power supply has a slight deviation in the square wave as compared to the other three.
Is this a problem? Picture A is the 3 banks picture, B is the one in question. thanks for any help

Need help 🙂
Please, if you're the "bits are bits" kind of guy, I would ask that you refrain from commenting, as by questions are based on the opposite attitude.

A couple of weeks ago I came to the conclusion that I wished to upgrade my Bluesound Node 2 (not 2i) streamer in 2020, and I began contemplating if the upgrade should be Raspbery Pi (or other SMC) based.

This is my baseline:
Bluesound Node 2 (connected with a coaxial cable)
NAD C510 DAC
Dual mono Pascal L-Pro2s amplifiers
Dynaudio Contour 60

Originally I wanted to switch my streamer out with a Node 2i, as it has been apraised for the improvement in sound quality compared to the Node 2 that I own. So my goal is to either match the SQ of the Node 2i or exceed it. I do wish to keep my external DAC, which does include both coax and USB input.

So for the last week I have been looking into SBC's and HAT's that be interesting, but I lack a comparison of the majority of them, and especially comparison between "tweaked" SBC's and RPi with hat.

These are some of the SBC's I've seen:
- Raspberry Pi 4
- Asus Tinker Board S
- Allo USBridge Signature
- Khadas VIM3

HAT's:
- HIFIBERRY DIGI+ PRO
- IAN CANADA TRANSPORTPI
- I2SoverUSB v.III
- Allo DigiOne Signature
- Allo DigiOne
- JustBoom Digi HAT

What should I go for?
Seing that my DAC accepts USB input, would it make sense to use an audio improved SBC as the Allo USBridge and just use the USB port, of would I get a better result using a RPi 4 with a hat and using coax, or even a combination of improved SBC and HAT? How do I get the best possible result with what is possible to buy and assemble?

All input and pointers are very much appreciated, just keep in mind that the total cost of electronics needs to a maximum of a $700. 🙂

Hi, I am going to build +-15/ +5 v power supply and post my schematic here for review.
The +5v is for arduino MCU controler



It is basically CRC filter and a voltage regulator.

Any suggestions/ comments about topology and parts value is appreciated.
F.ex.
- The electrolyte cap values in CRC - way too big before voltage regulator?
- The extra caps C111/112, C21/22
- Using one big polygon for DGND and AGND, instead of option for ground potential lift? I am schizophrenically afraid of ground loops...

July 9, 2020: This thread is evolving from selecting a Woofer for my WHW DIY project (selection is now closed - I've ordered four Peerless/Vifa/Tymphany NE315w-04's - they should be here by End of July, early August 2020.

The next phase will be to build and test the optimal enclosure for the woofers, since calculations show that a small 48L / 1.8 cu.ft enclosure is all that is needed for a sealed cabinet with F3 near 45 hz.
The quality I'm missing from my current speakers is that visceral thump from the kick-drum or fast Low Frequency transients (between 50 and 150 hz). I'm hoping these drivers can deliver that, so I will be paying attention to the enclosure to minimize vibration via damping and CLD techniques. I am also following several threads on cabinet construction to understand those concepts a bit better.

June 29th, 2020: See posts #38 and #54 for Sealed/Vented Box alignments and FR performance comparisons My current bias is to go sealed, due to the cabinet size requirements.



June 24th 2020: I'm looking for 12" woofer recommendations in the $100 to $250 range (each) I'm evaluating these options: (I'll be using 2 per cabinet)

1) SB Acoustics SB34NRX75-6 12" Woofer
2) Peerless SLS 830669 - 12" Woofer - Coated Paper Cone
3) Peavey pro 12
4) Dayton Audio RSS315HF-4 12" Reference HF Subwoofer 4 Ohm
5) Eclipse, W1238R 12" woofer
6) Peerless by Tymphany NE315W-04 12" Paper Cone NE Woofer 4 Ohm
7) Goldwood GW-12PC-8 12" Heavy Duty Woofer 8 Ohm


I'll be building a WHW with the Horn in the center similar to The Raptor ... a 10" MTM. One difference is that I would probably turn the horn vertical so that the horizontal dispersion angle is 40d and vertical dispersion is 60d, and I'd like to go with 12" woofers to get more slam and low end extension. (not sure about sealed or vented yet)

I recently received two 18 Sound XT1464 horns antwo SB65WBAC25s full range drivers (similar what was used here: A Bookshelf Multi-Way Point-Source Horn but I have room for a larger box. I think I'll use MiniDSP 4x10HD as a crossover, eq, and phase correction.

My Living Room is 13' wide, 24' deep and 9' tall. I'm usually sitting about 12' from the speakers which are toed-in near the corners of one end of the room. I currently have 2 B&W 640i as the mains, which are probably bouncing sound off the walls, roof and floor like crazy. (though I use the receiver's Audyssey Curve Editor to get a flat FR at the listening position - confirmed by REW).

Thanks - Six - Minneapolis.

Hi all,

I am at the beginning of a long journey... building my first true (fully self-developed) DIY speaker project. I have built several kits before and have also developed a very small 2.1 system for my PC workspace several years ago. These projects were cheap, with little amount of labor and cost involved. This will change now: 3-way active with Hypex Fusion amps, professional neodymium drivers and quite a lot of sawdust is to be expected.

Since I have several promising drivers for each position to compare, a lot of measurements will have to be conducted. These will be fully polar in order to obtain directivity patterns for each of the options. Now, I am tinkering with an automated turn-table approach.

For gated IR measurements I can use a large garden. Putting the prototype cabinet on a speaker-stand like this:

K&M 21435 Boxenstander – Musikhaus Thomann

will yield roughly 2m distance from the lawn. There is also no other obstacle (buildings, trees etc.) in this 2m radius around the pole. This will lead to about 9ms before the first reflections will hit the microphone (assuming 1m meter distance between baffle and mic). Please correct me if I am mistaken!

Now, instead of rotating the cabinet in two meters height (quite a mechanical challange...) I propose rotating the microphone around the center pole with a rather lightweight turntable mounted underneath the cabinet-plattform.

Is this (acoustically) sensible approach? Any ideas and comments are highly welcome!

kind regards

I have this small TDA2030 amp. Its lacking BASS.
Is there some way to have it put out more BASS?

Thanks for any suggestions.

On a ported speaker is there an easy way to make sure the drivers are sealed? I used a thin layer of silicone that I let dry well before putting in the driver. Or at low volumes is it even an issue?

hi all,

I upgraded and modified my Marantz 2330 :
- Replaced all electrolytic caps for Power supply P800, PE01, PH01, power amp P700
- Updated to film caps on the signal path and feedback path for tone preamp, and main power amp modules
- For Power supply P800 Updated to fast recovery diode (MUR1620CTG), H801, H802 to MJE15032G
- For main power amp P700, i replaced differential input pairs Q701, Q702, and Q703 to all KSC1845FTA with Q701 and Q702 matched hfe as closed to each other as possible

After all the mods & upgrades.
- I was able to observe a constant voltage of 35 Vdc of b/w J804 and J805 on P800. I noticed almost all of the new caps from P800 pwr supply are pretty warm to a bit hot the receiver is making music. Is it normal for PS caps to get warm to a bit hot with this high of power ? I upgraded the caps to all high temperature (105 C), low ripple, with higher voltage rating than original caps

- When adjusting bias current for both left and right power amps. I noticed 1 side of P700 is able to be adjusted to 13.5 mV and it stayed there after the amp is warmed up. The other side of P700 bias voltage is somehow jumps to 15 mV or 16 mV after it was settled at 13.5 mV as the other side. When it jumps to 15 mV, i readjust the trimpot to bring it back down to 13.5 mV, then the other side starts to slightly increase the bias. By the way, the P700 amp that has the jumping bias voltage is the one with the damaged and burned resistors/diode/transistors as explained below.

- After 2 days of music enjoyment, I smelled a funky smell and smoke coming out of the right channel of P700. This is the PA module that sit closed to power supply P800

Pulling both P700 boards out (left and right) with left was the one that sit closed by P800 board. I noticed
- R730, R732 resistors are complete toast (Please see photo)
- Q724 transistors are damaged with short from B to E
- Diode Q717 was burned. C720, C721 are burned (See photo)

Please see photo and schematic highlighted for the damage signal path.

Instead of replacing the damaged transistors, diodes, caps and resistors, I want to understand why it causes such behavior that leads to the damages for the R730, R732 paths all the way down to Q724, diode Q717

Can someone help me understand the circuit better (P700 schematic attached) ?What is the purpose of transistor Q724 ?
Does anyone know what the actual causes ? it only happens on 1 side of the P700 board. The other P700 board is fine and does not have any issues. I checked the each of the output power transistors and all of them are still alive and functional. Power supply still provide a constant 35V

I have a theory of C718 = 330pf is going bad and short circuit which allows DC current from bias transistor Q708 flow through B of Q724. Thus, it short ckt B to E of Q724 and burns R730 and R732 on its path. C718 does not look burned from visual inspection but I will remove it out of the PCB and check it.

Many thanks,
Tom

They are Celef CF1 Cirrus. Made in the UK, they became Proac later on I believe.

They need new drivers and probably crossovers I would think. They are a sealed design it looks like, Made out of 10mm chipboard veneer. So I am guessing the cabinet construction is not all that great.

Thought maybe I could put some nice new drivers and crossovers and might have a little gem? Or am I wasting my money?

I can post all the dimensions if anyone wants to make any reccomendations.


Thanks.

Hi
While I feel like coming along pretty well with most threads, I... always stagger at those abbreviations.
Does somebody know of a lexicon of sorts to be found, that I could print out as my cheatboard?

Furthermore: there are builds that can be either a line-stage or a preamp. I guess the difference is that a pre has (optional) an input-selector and a volume-pot? Or is there more under the hood?
Thank you [emoji1317]
David

Sorry posted in wrong section.

I am thinking of doing 3 mods to the torroid transformer in my amp but not sure if it will help.

1. Encase the tranformer in a steel casing to block the magnetic field.

2. Isolate the teansformer from the amp. Rest the transformer on a thick fiam pad so any mechanical hum is not transmitted to the chassis.

3. Fill the steel casing with non-conductive ferrofluid. I think this will help to cool the transformer. I am hoping it will perhaps improve the efficiency of the transformer as well.

Hi. Here I begin the estate sale of various items. A little story, one of audiophile friend past away just before Christmas. His widow was stuck with all his audio stuff, and I mean a lot... I'm helping her to sell as much stuff as I can. The large stuff I'll sale locally, but I'll put up for sale bit and parts here. The money will go the her 2 daugthers fund. So it is for a good cause.

FS pair of unused, still in their bag, Jantzen Alumen Z Cap (pair) - 8.2uF, 100V.

These caps are designed for tweeter and mids crossover applications:
-Pure aluminum foil with PP film dielectric construction
-Oxygen free copper leads helps lower series resistance
-Epoxy sealed ends and flame retardant tape wrap protects against high humidity
-Extremely tightly wound to prevent internal vibration and microphonic distortion

They are brand new, and they sale for 67U$ ea from Parts Connexion or 78US from Parts Express in the US.

I'm asking 50U$ each + shipping (shouldn't be too bad, it is a small box) and 3%Paypa fee

So 100U$ for a pair of great, brand new caps.
Let me know
Thanks
SB

Hi, I have a query and I hope that you can help me with.
I am starting out on building speakers and have no clue about electronics and would like to learn. To this end I am building my first speaker from a kit. The drivers I decided to get in Australia, but did not want to risk putting together the crossover, which I bought from the USA.
The crossover is put together as per wiring diagram of the speaker kit, except for one difference.
In the tweeter circuit, there is first a resistor going into a capacitor which feeds into a branch. First to an inductor which goes to ground. The second branch goes into another capacitor which feeds into a branch. The first goes into (according to the circuit drawing) an inductor, then into a resistor and then into a capacitor and then goes to ground.
On the circuit board supplied it is not as per the diagram. It is a sequence of capacitor into a resistor into a inductor, which then goes to ground.
I have queried this with the supplier, but would like to get a second opinion.

My question is, does it matter if the sequence is reversed and if so what would be the difference.
Another question is, are components usually mounted with the printing down? I would like to study how components are laid out, and, at a later date, maybe want a look again how it’s done. I don’t even know which way to point a capacitor in a circuit.

I can change the components around, but would really like a second opinion and maybe a short explanation.
The diagram in question is at Zaph|Audio - ZRT - Revelator Tower. I am building the enclosed version of the speakers.
I hope you can help me and clarify things.
Thank you for replying

Bluesound Node2 player streamer. Mint condition, rarely used just for testing.
Great reviews and a lot of awards as a very good product.
White colour.
Price 380€ plus shipping to EU.

Hello everyone

Hope you can help me. I changed the Output Transformers in one of my tube compressors. I used a LL7903 wired inverse 4:1.
The point is that I am getting a square wave peak at the very low end. No idea if it is resonance. The load impedance is 9K6 (tube output with decoupling cap [1.5uf]).
Do you know if a RC Network at the OT primary can help with this or is better to use another OT?

Thanks in advance.

Hi all hope somebody can help ..... I am after a schematic layout for this built up board ...... the reason is I have 24v transformer and I want to connect it so that I have +30v and ground. Presently this board is designed to give +VE and -VE and ground. If I connect AC and ground it works but I am only getting something like 1/4 wave rectification. I want to cut the boards tracks and re connect the -VE bank so that it works as positive.......... the transformer would then connect to each AC input but not ground....

The problem I have is this is dual layer circuit board .... so has anybody built one of these and can they help regarding a general schematic...









https://oi1064.photobucket.com/albums/u367/D3savage/Top again_zpsnkkeg3kj.jpg?t=1594110071

https://oi1064.photobucket.com/albums/u367/D3savage/Top Left_zpsyh7bgqkz.jpg?t=1594110096

Hi there,

i have a SPL Dynamics S2000D, Powersupply was broken, few parts on the Driverboard from PWM was missing, but i got this fixed. PSU runs fine.

On the output section i have only on 4 of 8 Fets signal on the gates.



From the IRS21844 the LO-signal works. The HO don´t.

When i measure on VB-pin, i have only few milivolts. Could this be right?

Thanks

Hi.
I have a pair of B&W DM602s amplified with Marantz PM6006.
My interest is to add two subwoofer speakers, one for each stereo channel.
The idea came to me when I saw a design in which the stands of the speakers were made with the boxes of the subwoofers.
It was called RS BASS STANDS.
Dayton Audio RS 225-8 speakers were used in a 1.3 cubic foot cabinet.
The link is this:
http://projectgallery.parts-express....rs-bass-stand/
My question is this:
Can I connect an 80hz passive low pass filter between the amplifier and subwoofer and in turn connect an 80hz passive high pass filter between the same amplifier and the B&W dm602 boxes ?.
Would it be correct ?. Would the impedance of the set be affected?
Filters are these
Parts Express 80 Hz Low Pass 8 Ohm Crossover
80 Hz High Pass 8 Ohm Crossover.
Thank you and I await your opinions.
Jose.

Hi,

I am designing a two way speaker with a loaded tweeter on a waveguide and a 7" woofer.

Looking at using one of these two wave-guides, the Monacor W300 and the WG-148R by Vistason. The Vistason has USA distribution (low shipping available now) but the Monacor does not, and the shipping is kind of pricey at this point due to Covid. The driver can be attached directly to the Vistason but you need a 3d printed adapter for the Monacor

I am thinking about a XT19, SB19 or the XT 25.

It seems that the Vistason loads at 650Hz while the Monacor at about 450Hz (see attached graphs). Both are done by the same person under similar conditions but they are different tweeters, that is the best compassion I could get to determine the point of loading.

How can I calculate the minimal crossover frequency on the wave-guide ( I am shooting for the vicinity of 1500 Hz)?

Regarding the choice of waveguide, is the Monacor worth waiting for and the extra work of the adapter, or does the Vistason provide the desired frequency point and a good compromise?

Regarding the graph, Sound pressure at angles (15 °, 30 °, 45 °, 60 °)

Tks in advance

Hello everyone, does someone has a spare output coil for this amplifier Twisted Sounds 8.5k board if so please let me know. Thank you.

I’m looking for Neurochrome parallel 86 boards. These were designed for the L.M 4780 chip. If you have any spares please send me a PM.

Hello,

I have a hi-fi stereo system sound with separate pre-amplifier (with source selector, tone control, etc) and power amplifier. I find my pre-amp great but the problem is that all of its controls are sliding style (including the volume that have separate sliders for R and L channels - this is a real pain!).

I'd like to know how hard is to build a small box with a single rotating stereo signal attenuator to place between my pre-amp and power. So basically the idea is to leave the volume controls of my pre at the maximum position and use the rotation knob to control the volume.

PS: my electronic knowledge is limited to solder things and basic recognition/comprehension of parts.

Thanks!

Hi,

Please find below the way I managed to connect 2 devices on I2S output/input, using a simple cable.

The source is a USB>spdif interface, having a I2S output over a HDMI plug : Gustard U12
The « receiver » is a FDA (Full digital Amplifier), a QLS-Hifi QA100, having a I2S input over a RJ45 plug.

In my case, the downstream device is a FDA, it could be a DAC of course.

I do not have background in electronics, thus I just made a trial, just by connecting the right pins from each side.

The result is fairly simple : it works perfectly. No hum, no EMI that alters the sound etc.

In my case, the SQ is equal using this I2S cable connection, to a standart toslink link between the Gustar U12 & the QA100.
Thus, no gain in this exemple in using I2S.
But after discussion with others we ends up to the conclusion that it is due to the QA100 that have very good other inputs (toslink, aes, coax, bnc), this makes the difference between these standard inputs & I2S negligeable.
For instance, using I2S on another FDA like I.AM.D V200 makes the SQ much better than coax or toslink inputs.

***************************

These are photos & pics to see what I did :

Wires & color code & pin No in RJ45 & HDMI cable/connectors : basics
Basicaly, as I had no idea about pins in HDMI & RJ45 ports before that job, I just found these info thanks to our mate Google.

HDMI side :
HMDI plug => these are the pins numbers :
HDMI wires inside : 7 simples wires + 4 main foiled cables each made of 3 wires
=> drawing :
=> same info with pins No :
=> cross section cable view :

The digital data flow FROM the Gustard U12 HDMI input.
This is the info regarding the pins No & functions on its I2S/HDMI ouput.
It is available on the seller web page.
Of course you need that info to go forward ; I don’t know if these relation pins No vs function is commom to all manafacturers… I would say so. Ask for the manufacturer of your device to be sure.
=> layout :


RJ45 side :
The digital data flow TO the QA100 I2S input over RJ45 plug.
This is the info regarding the pins No & functions on its input :
=> simple photo on the QA100, you have all the info =>

RJ45 cables & pins :
1st, I noticed there are 3 types of RJ45 connectors, with the references : EIA-568-A or -B or -C.
These are the differences, it is about a change in the pins No (FYI)
=> 1st type => EIA-568-A & -C

=> 2 type : EIA-568-B

Photo of the RJ45 I used, it is a B type, and the color code you can see through is OK :
Tricky point : on the 2nd RJ45 cable I tested, it was written on its side it was a « C » type, but the wire colors you could see thru the connectors indicated that it was a « B » type, thus I connected it like a B type and it was OK. So, check this.


Which wire on HDMI side corresponds to which wire on RJ45 side ?
Basically, according to the photo of the QA100, the I2S on the RJ45 side requires only 5 wires (http://img15.hostingpics.net/pics/88250820151119154231.jpg ) :
pin1 = LRCK
pin3 = DATA
pin5 = BCK
pin7 = MCLK
all other pins = ground

On HDMI side, you have, according to this diagram http://img15.hostingpics.net/pics/644095GustardU12HDMIpinscode.jpg you have more « useful » pins.
For instance, you have a +5V pin, and 4 pairs => DATA+ & DATA -, BCLK+ & BCLK- etc…
So, to make it simple, I thought it is a good idea to let the RJ45 port to lead that connection !
Thus :
I don’t care about +5V pin on the HDMI side, I don’t care either about the DATA- BCLK- etc…
I found nice & straight forward to connect : DATA (on RJ45) to DATA+ (on HDMI) etc… and connect 1 ground pin on the RJ45 to 1 ground pin on the HDMI side.

This is it.
Then I just had to find & connect the wires like described above.


Inside RJ45 & HDMI cable/connectors : wires ID

Inside HDMI cable :
- take off the PVC => http://img15.hostingpics.net/pics/75532020151121231715.jpg
nice shield + foil
- open the foil => http://img15.hostingpics.net/pics/32240820151121232323textarrow.jpg
you have the 4 groups of 3 wires, as it was showed on this drawing (« + » pin, « -« pin, and ground> http://img15.hostingpics.net/pics/551890HDMIcablefrontviewPinsNofunctions.jpg
- please note that the color of foils & inside wires does not match the diagram I found, this one : http://img15.hostingpics.net/pics/740755HDMIcablecolorscode.jpg
thus, the game was to guess > trial > error > trial. 2 small mistakes, but no time lost on this.

Inside RJ45 :
let’s look at a SSTP cable. As said above regarding RJ45, you have 8 pins, corresponding to 4 pairs of 2 cables.
take off the PVC => you found a shield (it is cut on this photo) => inside the 4 pairs, foild => inside this tiny foil, you find a pair.
=> http://img15.hostingpics.net/pics/60183620151122164714.jpg
According to the pins used in the I2S connection written on the QA100, and the basic data regarding RJ45 plug B type, you realise you need only to deal with the white wires, the other ones will correpond to « ground ».

Usually, each pair is : full color on 1 wire, and color/white on the other wire ; easy to distinguish all these 8 wires.
In my case, in this exemple, no « color/white » wires… they are only white… no a big deal to distinguish & avoid a complete mess between all these full white wires, but really annoying that « color code » seems to be « optional » whatever the cable producer…

Look at the connection : http://img15.hostingpics.net/pics/42762820151122164803.jpg
the orange wire is on the pin2 => it is a B type cable (although it is written « C type » on the cable…). Thus you know which wire at the cable end correponds to the pin at connector side.


1st connection trial : wire to wire

The 1st test consisted in connecting the 2 cables like this :

Fairly basic & easier to test the right link between pin & cables. For instance, useful when pins No & ID given by the manafacturer of the interface or/and the downstream device are not correct.
I made a mistake and inverted on the HDMI side the wire from the green foil (LRCK in fact) & the silver foil (BCK in fact) : I had some sound, but full of EMI etc…After inversion => dead clear & nice sound.


2nd & final connection trial : RJ45 wires on HDMI connector

The 1st trial allowed to understand the pin/wire links & ID.
Then, to have a ready to use cable, with EMI as low as possoble, I needed to soldier it somehow.
The best way I found was to soldier the RJ45 wires on the HDMI connector.

HDMI connector : inside
this is the connector =>
you have some silicone aournd to take off…
then take off the pins you do not need using cutter & clamp.
As seen before, I chose to deal with the pins of the HDMI, only the DATA+, BCLK+, LRCK+ ; MCLK+ (seen here : http://img15.hostingpics.net/pics/644095GustardU12HDMIpinscode.jpg )

ATTENTION : I kept 1 pin links to the ground.
Because on this photo => http://img15.hostingpics.net/pics/52331920151122100016.jpg for fun, I cut the ground link => big hum => I wired back 2 ground wire (1 from each cable) => no hum => nice & clear sound

So finally, I have the super nice HDMI connector
side 1 => http://img15.hostingpics.net/pics/53591120151122153356.jpg
side 2 => http://img15.hostingpics.net/pics/68408520151122153414.jpg ; here the non-green wire is the ground.

RJ45 cable prepared for soldering.
the RJ45 is fully open, no sheild, foild etc…. Ready to be soldiered on the connector => http://img15.hostingpics.net/pics/97436520151122174440.jpg
The trickiest part of the job for a newbie in soldering is ahead…

Note that on this photo you have 2 RJ45 cables.
Why ? because I have 2 QA100 amp. 2 FDA used in passive BI-AMPLICATION for my floorstanding speakers.
The nice thing with this type of cable & I2S connection is that, as mentioned Globulegl on a other thread, there is NO ISSUE regarding impedance voltage etc… too tricky stuff for newbies…
With I2S, just soldier 2 RJ45 cable on 1 HDMI connector, and data will flow without any issue from the HDMI interface to the 2 device downstream on RJ45 port, in sync : perfect solution for spliiting digital audio. Much cheaper than optical splitter of course, & even more cheap than my Mutec MC1.1+ (but the Mutec MC1.1+ can handle inputs… with this cable, you split only the I2S)

RJ45 cable soldiered on the HDMI connector
side 1 =>
Side 2 =>
So, as you can see :
- the blue wire, alone on the ground pin
- and 2 wires soldiered on each pin, because 2 RJ45 cable for my biamp.
- dots on the white wires, it was to distinguish the color of each pair (given than in that bloody cable, the color/white wires were fully white…)


RJ45 wires & HDMI pins combination

Thus, the combination to link the Gustard U12 to the QA100 is the following :

HDMI connector.
As mentionned above, on RJ45 side we need 4 « active » pins (thus 4 wires) + 1 for the ground.
Thus on the HDMI connector, I kept the following pins : No 1 - 4 - 7 - 10, for the « active wires » ; and the pin 11 to connect the ground.
Reminder, see here the pins No & location on the connector =>

On the HDMI pin 1 (DATA+), you connect the RJ45 pin 3 ; white/green wire of the RJ45 cable type B; or the white one in the foill where you have the green wire.
On the HDMI pin 4 (BCLK+), you connect the RJ45 pin 5 ; white/blue wire of the RJ45 cable type B; or the white one in the foill where you have the blue wire.
On the HDMI pin 7 (LRCK+), you connect the RJ45 pin 1 ; white/orange wire of the RJ45 cable type B; or the white one in the foill where you have the orange wire.
On the HDMI pin 10, you connect the RJ45 pin 7 ; white/brown wire of the RJ45 cable type B; or the white one in the foill where you have the brown wire.
On the HDMI pin 11 (for instance, or another one linked to ground according the Gustard U12 info), you connect a full colored wire of the RJ45 cable, I chose blue…

As you can see on this photo for instance, my soldering is pretty awful, but it works… so why bother with I2S ?...

***********************************************

Sorry if this post is too long and/or not clear. Feel free to ask if you can’t catch a word about this tricky but simple connection.
Hope it helps
Rgds

I've just dug this old PSU out of a pile of junk.

Just out of interest I'm rebuilding it to see what it is like.

My question is. what modern MOS-FET would you use in this application ?

Originally it would have been a HPWR6501 but that is missing.

For sale 2 Antek AS-4458 power transformer 400VA 2x58v @ 3.4A, 12v @ 2A, 18v @ 2A
Never used. 1 has been opened.

$80 shipped in the US

I have for sale a VZAudio amplifier control system. A amplifier control board version 5.3 I believe, DC detect and amplifier temperature sensor.

I had the system installed in Tribute 3000 amplifier and it worked perfectly. I no longer use the amp and it has been disassemble. I have another set of control boards and will no longer need these.

$165

I have for sale a never used pair of BMS 12n630 neodymium 12" subwoofer drivers. I opened one box just to look, the other box is unopened. Neither have been connected.

I purchased these about 3 months ago from Assistance Audio thinking I was going to build 2 subwoofers but changed my mind.

$285 ea. plus shipping

SPECIFICATIONS
Application Subwo
ofer
Nominal impedance:
Ohm
4 or 8
Power handling AES noise:
W
600
Sensitivity (1 W / 1 m):
dB
96
Frequency response:
Hz
25 - 300
Voice coil diameter:
mm
77 (3”)
Voice coil material:
Cu
Voice coil winding depth:
mm 26
Magnet gap depth:
mm
10
Basket:
Cast Aluminum
Effect. diaphragm diameter D
mm
252
Frequency response measured 100 W (28.3 V) at 1 m in a closed enclosure of 50 liter incl. 2nd and 3rd harmonic d-is tortion raised 20 dB.
Impedance – 8 Ohm driver

THIELE-SMALL PARAMETERS
Resonance frequency:
Fs
Hz
28.6
DC resistance:
Re
Ohm
6.00
Mechanical Q factor:
Qms
6.24
Electrical Q factor:
Qes
0.35
Total quality factor:
Qts
0.33
Equivalent volume:
Vas
l
85.5
Moving mass:
Mms
kg
0.127
Mechanical compl.:
Cms
mm / N
0.24
BL factor:
BL
Tesla m
19.8
Effective piston area:
Sd
m2
0.0498
Max. linear excursion:
Xmax
mm
±8
Voice coil inductance:
Le1k
mH
0.68
Le10k
mH
0.44

I am fooling around with some Eagle parts. Just wonder if anyone happen to have an Eagle library for the CMC teflon 9-pin tube socket? 🙂

Thanks.
Rol

Any suggestions what to do with 4 of these:

Peerless TG9FD 10 08 (Vifa 9 BG 119/8 Fibre Glas) kaufen bei hifisound.de

There are some box plans on that site too, but for a pair. I got 4 to put in motion.

I am thinking of an opamp amplifier where I could change its gain by changing resistors.
Using large SMD resistors, is there fasteners like small fuse holders to hold such resistors.
Do you see solutions that would achieve reliable contacts.
I do not want a pot, because I need fixed gains that are extremely stable, looking for no gain drift.

So I need to build a "subwoofer" for a Pioneer AVR; the AVR has a built-in crossover and a high pass filter, so I'm aiming for 45 to 200 Hz as determined by these.

I like closed box sound and don't want to build too big; 25 liters is fine.

I am down to a choice of two drivers: Dayton Audio DC200-8 and HiVi M8N. They cost similar money where I am.

A WinISD simulation gives slightly better bass in a 25 L box for the M8N, but this depends on speakers fitting the advertised parameters; and some reviews say the M8N only really fits them after long burn-in. I play music very quietly most of the time, so I am not sure my usage would provide effective burn-in.

So which one should I pick, after all?

Hello. Housecleaning continues...

DIYSG products:
1 pair of new, unused EOS-6 waveguides for use with 1” exit compression drivers. See photos below, the tooling marks are from the manufacturer and will obviously not affect performance. Asking $20 for the pair (OBO)

1 pair of new, unused SEOS-15 waveguides (matte) for use with 1” exit compression drivers. SOLD

Dayton Audio products:
These were purchased to build an inexpensive, compact, full-range monitor

1 new, unused DC28FT 1-1/8” truncated silk dome tweeter. See group photo. $14
1 new, unused DC130AS-8 5-1/4” shielded woofer. See group photo. $14
1 pair of new, unused ND140-PR aluminum cone passive radiators. One box unopened, see group photo. $16 for the pair.

I will sell the Dayton lot for $35

CONUS ONLY, all prices plus shipping.

SEE POST #4 FOR PHOTOS

Hello,

Has anybody here used Welcome To Sound Audio Manufacturing for their PCBs?

What has been your experience?

Thanks;
Leo

Hi !!

I have a Nad 2600A that is burning its 10A fuses (and main one once). Other fuses are OK. I replaced them once but they burnt in the second in a stylish green spark 🙂

I have some knowledge of digital electronics, and kinda know my way around a soldering iron, but analog stuff is not my cup of tea unfortunately.

Could somebody point me in the right direction ? Is it worth the effort ?

Thanks a lot !

I have a pair of A7s: 416C 902A+811B plus a Fostex A90 supertweeter all going through the JE Labs passive XO (1k6 I think) and 1.33uF direct to the supertweeter. Driven by either 6V6 triode PP at ~3W or EL84 UL PP at ~10W.

I would like a bit more bass (of course!!) any suggestions as to a matching sub design? Not too clued up on LS design but do build all my own electronics so not afraid pf dirtying the hands. Are horn subs possible?

Having a bit of a clear out. UK based.

I know they are not necessarily DIY but thought someone on here may be interested.

1) Audio GD NFB3.1 DAC (upgraded)

Dual WM8741 dac chips and dual mono power supply design.

Good used condition minor scratches to case, Coax/USB/Toslink input, 2.5V (variable) and 2mA outputs, DIR9001 coax board, Audio GD supplied Amanero USB card, selectable filters, 10k ohm Log Dale Resistor ladder attenuator on outputs to make it variable, solid aluminium volume knob, Mogami cable. (comes with original Tenor USB card)

I use it directly with active monitors and it works really well, very clear and nothing but a resistor in the audio output. Could also be used with older amplifiers with lower voltage inputs.

£300 + Postage (in mainland UK) (or pickup see below)



2) Linn Axis turntable with Linn Basik Plus tonearm and Audio Technical VM95ML (micro linear) cartridge (stylus has 200 hours used out of 1000 hour life)

Very Good condition, lid has minor scratches but is clear and not cloudy, new hinges so they are not cracked and do work, wood surround very good, speed control works fine. Sounds wonderful, with the ML stylus on the AT VM95 body it digs out so much detail.

Comes with a Linn A2D phono stage in very good condition

£425 - prefer pick up in West Sussex or possibly drop off in Farnborough, Salisbury or occasionally Bristol.





More photos on my Flickr account - Items for Sale | Flickr

Also have videos of the volume control and turntable working if required.

Any questions please ask.

Im looking to buy a pair of this CCS boards if someone have this for sale.Send me email.

I replaced the driver transistors and diode and gate resistors on all 4 banks. When I check the drive signal 3 banks are at 4.04v and one of them is at 3.75v. The square waves look good and the drive signals coming off of the center leg of the fets of all 4 banks are identical in shape and voltage. When I check the voltage on the rails the +hv rail is at 162vdc but the -hv rail is at 4v. The board is in the heatsink will all screws for testing.

Reviewing some old Audio Express mags, I've been tempted to bypass the tweeters in my Klipsch Tangent 40Ws and replace them with the JBL2404H "baby butt" tweeters to remove some shoutiness I've experienced with these speakers. I've heard that the horn tweeters standard on these speakers aren't the best on the planet....

Though I've been part of these forums for many years at a low level of activity, I haven't introduced myself.

I'm in my early 30s living in Zurich, and have completed a couple of speaker projects (a small 2 way according to Tony Gee, as well as the 4-way dipole Nao Note II). I haven't designed any of my own speakers, and beyond wiring together some Class D boards into amps for the Nao Note IIs, haven't done much in the way of electronic components either.

I'm interested in optimizing room acoustics and listening to different DIY speakers and setups, so if anyone is in the Zurich area and interested in listening sessions and swapping ideas, PM me.

Musical interests lie most heavily in the classical tradition, everything from pre-baroque to modern composers, though there's plenty of electronic, traditional/folk/world, jazz, rock, etc. in the rotation.

John G.
I have a Technics SL-P990 cd player which will not play unless I manually spin the disc. Several people have reported a similar problem. The cure appears to be changing 2 smd capacitors associated with the motor drive. Can any body tell me the value and number of these capacitors on the circuit diagram and roughly where they are on the board. The SL-P990 does not appear to have a separate motor board, so they must be somewhere on the main board.
Thanks, John.

North Creek speaker kit CM-7. Includes 2 tower, 1 center and 2 monitors. Does not include cabinets. This is the kit as shipped from North Creek. No assembly has been attempted. Will ship for cost. Best offer.

Sorry but this is winding up being a difficult thing to find with Google... I'm getting every kind of sniffer/sensor probe coming up except for what I'm looking for.

Does anyone have a schematic for a device that can detect and amplify hum emitted by chokes, transformers, wires, etc. I've seen guys who made these. I suspect It's basically a coil pickup probe point, hooked up to a small op amp and small speaker, maybe a VU meter too. It is used to probe around the empty space of a chassis to find where hum is being emitted. It can be used to position chokes and transformers, detect what sides of a coil might be emitting the most or least hum field, etc. It would be a handy device for valve construction.

I would like to make one out of junk box parts on hand, if anyone has a good schematic for one of these. Could they share it?

Hi,

now my friend have a problem with Audio Note Conquest. One of the capacitor (marked red) blowed up second time. First one was 470uF 385V, second time was 470uF 500V. Do you have any ideas why this capacitor goes bad?

Best regards

hey all


so i snatched up a heck of a deal on a 5.1 system (def tech bp7006, clr2002, studio monitor 350, mirage s8) for $150


however the amps in the bp7006s are shot. they do work, but barely any output. this appears to be a very common problem for the 700x modules, so replacing them with the same troubled module for nearly 200/ea just isnt worth it



i attempted the 'hum fix' which entailed replacing a small capacitor bank on the amp, which did not address the issue. i measured the 5k pots which one measured 33-39k (nice) and the other goes from 8k-12k, so i bypassed the pot, to no measurable improvement. so i suspect the main 80v 6800uf caps might be at play here, but for the price of them (heck even finding them), i could just fit in a new board into the mix



inside these units, there are some nice toroidal transformers (49.5-24-0-24-49.5), so i didnt want these to go to waste. there is no markings for a VA rating, but there is a T 3.2A L 250V fuse on the unit. so perhaps someone could help maybe give a round about idea of the output


i dont mind clogging up any existing holes on the mounting plate, so trying to get something to fit the holes exactly is not really a requirement. and i'm not concerned with the fact that these can take either rca or speaker level input, sacrifices will have to be made there, plus the rca method imo is a better way for them to be hooked up anyway



so looking at some options, in the ease of 'plug and play' i was looking at the BTL tda8954th boards, they accept a simple ACV input, so one less thing to deal with, but i'd really only be using the 24v leads and i feel like there may be options to use the 49.5v leads instead? also, the drivers are 4ohm, not sure how the 8954th boards would do btl into 4ohm as i believe it's rated SE 4ohm BTL 8ohm according to the spec sheet. i thought i read 1.2v input for max output, and with an avr generally you'll only get 0.7v so perhaps thats enough to subdue the board into an acceptable range?



thoughts? i wanted to be able to share this fix/option with the deftech community who are stuck buying $200 replacements over and over again just to get another board due to fail. def tech used to be cool and just replace them at no charge, but since being bought, they have tightened the belt


anyway, here are some pics of the modules, i'll work up some wood/allumium mounting to get everything to fit once i find the board i'll be using as a drop in


thanks for anyone who has some ideas and ways to help!

Hello everyone,can anyone identify me this GZ34,the tube has no code.I am interested in who is the manufacturer of this tube,the factory,and if anyone knows year.Here are the pictures.Thanks

Maybe this is the correct forum (and not the Pass one).
I'm a very newby in electronics but I would like to try to build a Pass F5.
Only the F5 board and not the PSU, so I need a built PSU.
Best trafo than switching type...
Output should be +/-24 V plus the Ground with about 300W.

Please help me to choos the right one!!


Danilo

Good day.

I would like to build a good DAC.

I want to use the AK4493 DAC or 4495 even 4497 will do with LT3042.
Where can be find good layout for 4-layer PCB?

Thx.

Hi Guys,
I've built a set of Pensil cabinets out of Birch ply, not Baltic Birch alas. I need to mount the drivers on the wide side of the cabinet not the skinny as the instructions specify. Several years ago I recall one of the gurus (Scott or Dave or?) blessing this driver location. I've made the backs and bottoms removable so internal stuffing or lining will be easy. The Pensil specs call for some level of stuffing. I'm happy to use poly-fill or some other variant but am curious of the intent. Are we stuffing the cabinet to dampen cabinet vibrations to reduce unwanted coloration, slowing or speeding up the air flow to the terminus or something else? Also, should I still put the port on the same face as the driver? My plan is to have them painted by a car shop that painted my Fried subwoofers which have held up really well.
Thanks for any and all input.
Mark

Hello!

I've searched the last 2 weeks for Audio Players for my Raspberry Pi, but yet haven't found one that fits my purpose.
In theory its really simple:
My hardware includes a Pi (2 or 3) and a cheap amplifier plus speakers, there is no need for a good hifi experience.
I just want an offline player, that starts very quickly (because no special modules/services) and auto play all audio data on the USB stick I insert. Its headless and should work without any command, just like switching music CD's.

I tried PiCorePlayer because of its merit to poweroff without harm, but couldn't get it to work. Forum members said the player has to be online and can't autoplay.
MoOde, Volumio and RuneAudio should be similar and have way more features I don't want. MoOde ought to have many configurations, but the same problem as PiCorePlayer I estimate?

My next steps would be trying Archlinuxarm and then pygame, but I also don't know if it works there.
What would be the best solution for my task?

If it has to be online, I will accept that, but USB autoplay on boot and switching USB stick has to work!


Thanks in advance!

I have a dc audio 7k that pops when it shuts down. Any ideas what is causing this?

Also known as the "Death Of the Staircase". My previous design was called "The Staircase", so I thought of putting it to an end. 😀 This is the 3rd reconstruction of the amplifier with mostly the same parts, but a new chassis. The reason for rebuilding the old and not making a new is because it's cheaper - not having to buy entirely new parts. Afterwards it's my first and it will always be my amplifier for learning and practicing.

This version has improved chassis - rigid, very thick pine wood; coupling - interstage transformer 1:1; power supply - RIFA PEH169 high grade capacitors.

It is not completed yet. I have to build transformer housings, put black plate screws, tube top cap insulation and... I'm also winding hi-fi low Cp and low DCR psu chokes and maybe I'll do a higher grade power transformer. I'm very tempted to try regulation, maybe salas SSHV for the driver stage and "something else"for the output stage.

Every component is described in the schematic right here! It says it all.

I'm very happy with the result - smooth, liquid, live sound that makes you go into extasy right away 😀. The bass is a little slow and I guess the high PSU DCR is to blame, this is why I'm tempted for the regulation. Ideas never stop.

The power output is 11W. There are no power switches. The power cords are Neotech 3PS25 terminated with Valab rhodium IEC and plug. There is a separate power cord for the heaters.

Enjoy the pics. I'll shoot some more in a more thorough way these days.

Hi @all,

i work the last days on a broken amp. One fet in channel 4 was broken.

3 channels run fine. If i replace the broken, the new one gets in a few seconds really hot and the amp goes in protect.

I see that between gate and source was a difference of 6V DC. None of the other channel has it.

I replaced all the green marked fets, transistors, diodes, OP amp too.

but it will not work.

Anyone any idea?

Dropbox - IMG_20200630_211903.jpg - Simplify your life

Thanks

Hi,

I'm curious about the impedance curve of my new esl panels. I have REW installed on my laptop, but my laptop has only a mic out jack, no line inputs. I would like to use this scheme:

https://www.roomeqwizard.com/help/images/impedancesetup.jpg

I'm wondering what would be a good way to make a impedance plot with my laptop + REW: would an external USB soundcard with line input and mic output work? Something like this soundcard:

Product

Greetings, all. First post; retired lifelong police officer, turbine helicopter geek, as likely to go necrotic as quickly as this thread will.

I hope it helps somebody, somewhere, in whatever your future allows. The following is my way of giving back, to this group, especially.
Thank All Ya'll Very Much, DIYAudionerds. Your existence only enhances life quality.

A Gut, Hack, Mod and Polish Turd-Treat Especial*. A Moldie Oldie, but Goldie.
An Ambitiously Absurd Tale of Transforming Surplus into Slightly Better Surplus.
For Dummies, by a Dummy. *AvE

VICTIM
Anchor Audio Xtreme XTR6000CU1 Sound Reinforcement System, aka Anchor's obsolete, disowned millenial era bas_ard child, a Kitchen Sink Combo Cab, sans batterias.

SITREP:
-2016. Purely ignorant, infatuous impulse purchase. Lubbock TX pawn shop, $100. History unknown. "Very good knick", my Brit brothers might say.
-Clueless (Anchor Audio who?) but absolutely intrigued by its MILSPEC-like construction/design, etc; in a word, outstanding.
-Made in the State of Degeneration nee California in the late '90's, apparently. In spite of this, clearly built to be as indestructible as a Smyrna Glockenspiel.

-**Turns out, Anchor only markets to, essentially, "wedding rentals" alongside their corporate/conference/commercial venue et.al. demograph. Hidden secret in plain sight, hence my highly educated, yet total, ignorance of them.

NERDISTRY:
(representative internal pics will follow, precise photos upon forum request.)
The public marketing-wank brochure specs are readily available, but almost nothing else. Surprisingly scant info. Webwashed.

-The bi-amped thing is bi-bi-amped, QUAD-amped, essentially.
"Proprietary", through-hole mother-daughtercard mezzanine design, aviation-quality assembly. Every PCB crisply marked with pinouts & traces. Impressive and Unusual. HackNmod Freedom Bonus Points=Anchor, Inc.

-An apocryphal tale references a "passive companion speaker", its existence known by few, and seen by fewer....The 6001, allegedly born to suckle from a then-obscure oddity, 4-pole biamplified Speakon Socket. Professional Prescience Bonus Point=Anchor, Inc.
-properly and precisely shielded & separated ERFI noisy-bits.

-"DIVERSITY" UHF wireless RX module, 1-channel. For the tinker bits bin; unneeded, obsolete & unsupported, but a fascinating little RF device, and 12VDC...[more on that later.]
Conjoined to its plate-steel housing, (was) a then-high-end, Belgian Samsung DAC'd, 12VDC OEM CDR used in a few BMWs. Combined, they fill a single DIN or 1/2U space, with intriguing possibilities, as will follow.

GOAL:
Meh. Learning experience, heckuva lot of fun. Flying OClamps fitted, repurposed PDU PCB, etcetcetc. Maximum overdrive mods, because if worth doing, its worth overdoing. No rabbit hole too deep.

Anybody interested in specific details from here, I'll do my best to cover it with specificity. Otherwise, I'll gradually post the processes & pieces I used in coming days.

Eric

Found an old NAD T760 which needed a little TLC, clean it up, straighten the case etc. The only issue it had was a hum in the rear channels.

Initially using the optical input the noise was horrendous but calmed down after a few minutes but was still quite audible. If you just use the analog inputs things improve in all channels and if you use the pre-out RCA connectors the sound is again clean.

This led me to the belief the hum must be isolated to the surround board and changing the caps to newer ones would clean up the signal, so fitted some Elna Silmic II. I double checked the connections after I did each one and validated the caps were the same way round as before.

Put everything back together and while the rear channels sounds better the original hum is worse than before, not horrendous and when you watch a film it isn't very noticiable but I would like to resolve the issue if I can.

A visual inspection of the board looks fine and when I plugged it back in nothing I could reach got hot nor did the heatsink the transistors are attached to.

I do have some initial thoughts but would really appreciate any suggestions on what I could do to resolve this. I am no expert, not even at an intermediate level but I am trying to learn and happy to have a go.

A few thoughts I had:

Wondered it a shielded power supply would help.

The board has empty junction connectors marked A and B thought of connecting them with a separate wire

Could there be interference from the power supply which is right next to the board

Could there be interference from the AC3 board which has a random wire running to the surround board. NB. There are a few extra wires connecting boards together which I think is factory as I saw this in pictures of another T760 just a bit bizarre.

As I said, your suggestions would be appreciated

Happy Independence Day to all the USA members here! Have a good one and enjoy! 🙂

I had posed a question in the Aleph J thread a number of months ago to see if there was any reason I shouldn't try the following, and not receiving any negative feedback, I went ahead and made the changes this past week.

I had built an M2 and an Aleph J a while back. I've always loved the stereo imaging and sound-stage depth I get from mono-blocks, so I wanted to convert my amps to mono-blocks - but the expense for the extra chassis and power supplies kept me from doing so.

Since the Aleph J and the M2 use the same power supply, I decided to swap an Aleph J channel for an M2 channel between amps, so each amp has one Aleph J and one M2 board. I installed a heavy duty DPDT switch on the back of each amp, unhooked the V+ and V- from the power supply to the boards, and instead ran the V+ and V- to the center pole of the switch, and then ran lines from the switch to the V+ and V- of the audio boards. I didn't do anything with the ground lines.

The power supply in each amp now only powers one board depending on the position of the switch, and I change the RCA input, speaker outputs and switch position depending on whether I want to hear M2 mono-blocks or Aleph J mono-blocks.

How did it turn out? Really well. I always had a bit of a ground loop that I could hear in my Aleph J if my ears were close to the speakers. Beyond the increase in separation that mono-blocks bring, now both the M2 and the Aleph J are totally silent with my ears right next to the drivers.

Both amps were built with Antek 18V 300 VAC transformers. As a stereo amp with this transformer, the M2 sounded very pretty for jazz, and folk type music, but wouldn't really rock to satisfaction. Dedicating the power supply to a single audio board has given the M2 much more bass drive and punch. I was actually shocked at the difference, as I wasn't expecting it. Now the amp can rock as well.

Hear are a few not-so-great pictures that demonstrate the change.

P.S. Not that there would be any reason to, but as 6L6 pointed out when I asked about the idea earlier, you would never want to flip the switch while the amp is running.

I have 2 OPPO Sonica DAC's. In general, I really like the DAC and she plays beautifully w/DSF files from the hard drive.


Background: One of the Sonica's suddenly sound's slightly muddy or more like listening through a veil, lacking authority or punch. Frankly if I heard this DAC standalone for the first time, I would have assumed "meh, nice but not that impressed".


Performing an A-B swap out of one Sonica for the other, clearly demonstrates it's the DAC.


Question: Any idea what to check?

Thanks for any guidance.

HQ-Audio ESS9018 Reference DAC for sale, 500$ O.B.O.

Hi. Selling my great HQ-Audio (quanghao forum member). This is a great dac and it was my best dac before I upgraded to quanghao latest ESS9038/Tube I/V DAC. So Mine is for sale. It has the solid-state dula mono I/V converter and high current Class-A output stage. Full discrete low noise regulators for each DAC section, I/V section inspired by dCs apparently. Each I/V channel has +/- low noise shunt regulators. Excellent design and implementation, Sounds great!

Mine as these mods:
-Replaced the MELF stock I/V resistors with Nude Vishay resistors for best sound. A substancial upgrade!
-Installed a rear mounted 1/4'' headphone jack. The output section is powerfull enough to drive an headphone with ease.

It has the Amanero USB input that works great with my music server.
It has also coaxial, AES/EBU and optical SPDIF.
Everything is working perfectly.
Silver color, comes with remote. Accept up to 24bits/384Khz and DSD as well.

Asking 650U$ (O.B.O.) + Paypal fee + Shipping.

You won't find a better dac at this price...

Thanks for looking
SB

Hello Phreax !

I´m confused. I want to build my own High-End-CD-Player.
For the CD-Transport-Unit i want use an expensive Philips-VAU 1252 with the "I2S" Output. This is very good ,because i´m not use a Digital-Interface-receiver (like CS8412,CS8414..).
The Digital-Filter (DF17xx,..) i don´t use, too !
It´s very minimal: Only 2 piece ob Burr-Browns "PCM63" direct coupled to the Philips !
There is only one problem : The PCM63 is not "Stereo", I need
2 piece for a Stereo-DAC. But is there a way to "divide" or seperate the "I2S"-Signals for the "Left"- and the "Right"-Channel.

Then i thougt, i can take the "PCM69" because it´s a Monolithic-Chip "Stereo-DAC", but i cannot get this Type here in Germany.

Is there anybody there with a little Tip for me and my problem ...?

greetings from Obelix

I was wondering if anyone had done anything in the area of detecting shorts on power amp speaker outputs while the amp has its output muted by SSR.

What I mean is using some way to sense possible shorts on the speaker side while the speaker is disconnected from the amp by the SSR.

It's not difficult to do with electromechanical relays, using the other side of the switch that would normally not be used, to pickup the lead from the speaker while it's not physically linked to the amp's output, and when the relay is energized to unmute, the speaker is connected while the short sensing circuit no longer is...

The thing is, it's a bit different with SSRs, with no physical contacts being used, and there would be no way to disconnect the short sensing circuitry from the speaker once the amp is unmuted.

So far I haven't found any way to do this with SSRs, but perhaps some have given some thoughts and may have come up with something usable?

Do you think this is enough heatsink for two DLH amps? I think I pulled it off of a powered sub so not new and no spec's. ( No idea why it flipped the picts ).

Hey everyone.

So I've made my 3 way cabs and dicided to go active and my setup is 1x 2 channel amp for the 12" subs and 1x 4ch amp for the tweeters and mids and an active crossover unit to separate the frequencies.

I was in the studio the other night giving them a first test and managed to set everything up nicely and they sounded great but when it got to a live gig they really under performance in the sense of I could hardly get any volume out of them before feedback occurring!

My main question is do all amp channels need to clip at the same time as the mixer?

I ask this because all amps channels are just about registering a signal according to their displays while the mixer is at optimum levels. Obviously I haven't set the amps correctly but I just wanted to know if they all need to clip at the same time?

Hope this makes sense!
Sal

(delete)

Sorry, thought my post was gone and wrote it again.
How to delete this thread?

Dwm0608X_V20
any way to get these board somewhere,
its installed on a Ground zero gzua 1.1000dx.
Or if someone sits on scematic on this board. ?

I overheated the pads on the to ics so pretty much destroyed the copperlines around.
i reflowed the u2 an u3 too many times ,
i assume u2 was tl072 and u3 is lm311 or 211..

so it got this board messed up.

best regards
Niklas .

I am working on a OTL headphone amplifier where noise and hum is essential. I can't help being nervous about having AC on my heaters for the 6AS7 output tubes and 6SN7 small signal tubes.
I have done some reading about maybe applying DC to the heaters to eliminate the risk of 50hz noise. I can see that DC on the heaters is not something you do without side effects. My idea however is to mount the heaters in a MOSFET H-bridge so I can switch the current direction with 1Hz or so.
Would this idea give me the best or the worst of both worlds?
For the power supply itself I'm thinking of using a toroid transformer with the heaters in parallel if I go with the pure AC option. If I go for the switched DC I am planning on something like a Mean Well LRS-75-12 with the tubes in series of pairs.