Hi,

I try to find UPOCC RCA sockets (female) connectors but it seems that there are none on the market: it is possible to find such male connectors, but not female (chassis) connectors.

Do you know any of them ?

Anyone remember this board that was part of a group buy years ago? I dug out four of them but couldn't find the info. Does anyone have the info on these?

obit from today's New York Times:

Chuck Peddle Dies at 82; His $25 Chip Helped Start the PC Age - The New York Times

Chuck Peddle, the engineer and entrepreneur who helped launch the age of the personal computer after designing a microprocessor that sold for a mere $25, died on Dec. 15 at his home in Santa Cruz, Calif. He was 82.

His partner, Kathleen Shaeffer, said the cause was pancreatic cancer.

In 1974, Mr. Peddle and several other engineers were designing a new silicon chip at the Motorola Corporation in Phoenix when the company sent him a letter demanding that he shut the project down.

Mr. Peddle envisioned an ultra-low-cost chip that could bring digital technology to a new breed of consumer devices, from cash registers to personal computers. But his bosses saw it as unwanted in-house competition for the $300 processor Motorola had unveiled that year.

So Mr. Peddle moved the project to MOS Technology, a rival chip maker near Valley Forge, Pa., taking seven other Motorola engineers with him. There they built a processor called the 6502. Priced at $25 — the cost of a dinner for four, and the equivalent of about $130 today — this chip soon powered the first big wave of personal computers in both the United States and Britain, including the Apple II and the Commodore PET.

Hello all!

I'm searching a LCBPS pcb or a finished board. A tpsa7a4701 / -3301 supply can also be used for the planned use.

Thanks for your offer in advance

Hi i am looking for 2 Altec 1579 A

Maybe someone can Help me and has it around?

Thanks!🙂

Tang Band W8-1772

I've been reading with interest an article using these Tang Band full range units.

Has anyone had any experience with them ?

Hi all,

years ago I built 2 Eiclone monoblock amplifiers, following the schematic of diytube.com, using the tube rectifier insted the solidstate, so the secondary winding of the power transformer was calculated considering the voltage drop of the GZ34.
The amps after hours of operation still sound good, but I have a higher B+ than the project data, 515V vs. 485V. How I could reduce it?
Otherwise I would switch the power tubes to Tung-Sol 6550. What to do you think of these tubes? Can be a good improvement?

Many thanks
Regards from Italy
Andrea

I have Audison LRX 1.1k with this problem.When i connect 12v - and+ this resistos from pictures start to increase temperature without any stabilization..If i remove CPU pcb temperature stop raise.I verified all transistors from pcb and seems ok.This resistors must be from aux supply 15v..This problem happen even if REMOTE is or not connected.If somebody know better this type of amplifier please leave here,diagram,message!😕

Hello everybody,
I'm a beginner, I'm here to learn.
Thanks for your information

Hello together,

I'm new to this forum and in parts to audio processing (digital signal processing, analog circui desing for HF applications i'm into if it comes to digital signal transmission), so i want to say sorry for my stupid question in advance, and for my bad english as well.

However, i have studied electrical engineering and worked in the past years on lighting and home automation (hobby wise). During the last years i worked on my PhD in computer science, which is the cause why I forgott some details on signal processing :/. Anyway now i want to prcatice those skills and planned, to build my own AV-Receiver, based on the TI class-D amplifiers. The plan is to grab 5.1 Audio from the HDMI and Tosslink/AES-3 protocol. The latter, however, is one of the later steps as it seems to be more complex than expected, thus i will work on the analog back end and use as a stopgap with a COTS 5.1 audio grabber as the backend is finished (which is a lot of work anyway 🙂).

So hopefully i can provide some helpfull comments and get some if i got stuck at a ceartain point.

Best regards Björn

Hello for everybody. I have a problem eith my hifonics bxi 3000d. I have rail supply and without output transistor(irfp250) square signal is present on gate . When i try to mount transistor that square signal is missing and other side (low side) become verry hot , amplifier remaining in protection. Now i removed al output transistor and square signal on left side is again present. Every time when i tryed to instal transistor that signal disapear. Al transistors are good also irs21844s . I wait some answers!:-| thank you !!

Dear Guys,

i have a KRK Rockit 8 G2. And sometimes it just stops working without a reason. And some hours later its just working again.

I don't think its a heating problem because it also happens if the speaker was switched off for hours.

Any ideas? I already opened it and had a look inside but could find anything unnormal. But I'm not really into this stuff so I will attach the pictures I took. Maybe you guys can see more.

Thanks for your help.

Hello,
While working on my android tablet HU for car I accidentally desoldered smd component that is in series with D+ line for usb, there is also the same one for D-, but there is nothing writen on it. I checked with microscope...
I measured the same smd from D- and it`s not a diode, it`s resistance is 0.2ohm.
It`s black and I think it`s a 0402 size...
So ok I tought it`s a black smd, its got to be a resistor, so I soldered 0.2ohm 0805 smd resistor instead of it... But I get error message "Device descriptor request failed" in windows...
I can confirm that I get 5v on VBUS and GND if I short ID pin to GND (OTG mode), I have 96,5kOhm resistance towards the GND from both D+ and D- lines...
That would confirm that everything is soldered correctly, no shorts...

That being said, that SMD component must be something else...

I can find no schematics only of any phone, tablet...
Does anyone know what would it be?
It`s a black SMD, I think 0402 with resistance of 0.2ohm in series with D+, where is another one in series with D-, followed by common choke...

Thank you for your time and help

Does anyone know if all the audio driverboards and outputs have to be in this amp in order for it to have output?

I’m working on 2 channel at a time and can’t get any output from any channel .

I know the amp won’t have output on the channels the outputs are missing from but the other 2 channels also have no output

Still cleaning out of my cartridge stash, to make room for other diy projects 🙂
This time the former flagship of Ortofon´s Rondo series, the Rondo Bronze.
Just retipped by Hans-Peter Grasse at Techne Audio in Germany.

Home - TechneAudio

Just played 3 records to make sure, everything is in perfect order. It performs flawlessly and as original tracks 80uM with 2.3 gram stylus pressure (2-2,5 recommended):
It´s retipped with boron cantilever and ML stylus.
Neutral, tipping to slightly warm, lovely midrange and superbly defined high´s.

Selling for 500 Euro´s (paypal, family and friends) and I´ll carry the shipping costs.

Just built a version of this, but with Seas 27TFFFC instead of the original H087 tweeter. Filter is 4.7 uF and 2.2 ohm. I have never heard the original Dynaco 25, but I am stunned by the sound they make with the 27TFFC tweeter.

It is detailed, and at the same time exremely relaxed. It can play loud without being tiring. When pushed very hard on some music you can hear the tweeter struggling a bit, but this is at sound levels much higher than I ever normally listen to.

It is strange to me that a 10" bass/midrange can provide so good midrange! Both male and female voices just sounds magical. I wonder if this is because the lack of filter on the woofer, or is it just an exeptional good driver? It is hard to be believe it was produced in 1971. Bass is not very deep but fast and always present, without being too much.

Have anyone compared the A25 to the new version from seas A26?
I have read that some people just think the A26 is a marketing gimmic from seas just for profit.. I need to the hear the A26 first but I find it hard to believe

I'm just curious to hear what commercial phono preamp built in any type of receiver or preamplifier from the 70's to the 90's you liked the most.

Just finished building my "portable" boombox. It's powered by a battery but still not very portable because of how heavy it is 😀. Just for feedback, is this a respectable response? I just finished taking measurements today. It sounds alright to me though, considering I can carry it around if I really wanted to. Spent a total of $500 in parts including wood, drivers, everything, just was wondering if I did okay considering the cost, I don't have many friends who are into sound lol.

Hi all,

First post here.

By mistake, I have ended up with two x 4-inch Tectonic sub drivers.

I don't want them to go to waste, so I was thinking of building a box in which to fit them.

I have a B&W DB2 in my stereo system and wanted to build a box to place the drivers in a similar orientation, i.e on opposite sides.

This will be a passive system driven by an external amp.

I am 3D printing a pair of spiral speakers to use a 4" full-range and this sub cold compliment these.

Does anyone have any suggestions?

Thanks

caleb

Hi all

I have been out of the game for some time, but I think that now I am finally ready to do that DIY project.

Can you recommend any 2» semi fullrange drivers? I am thinking about splitting at 300 Hz or so to a sub.

Regards
C&H

I don't understand what this waveform in the attached photo is telling me.

It has a significant dip in the top before it pulls down. This bank is heating up with a 2ohm limiter but i do have the fets clamped similar to what you have recommended in the past with a binding clip and an old clamp from a kicker.

Its taken from the Gate of IRF3205 Q16A. It drives the transformer that has the additional winding for the 15V regulators.

The probe is grounded to the source leg.

Photo #2 shows the waveform I am seeing on the gate of the other banks driving different transformers.

Thanks so much to get me in the community. I wish all of you and the human being overcoming the struggle against the corona virus. I'm a medical doctor (Cardiovascular surgeon) in Istanbul. Recently I've begun in interesting with vintage reel to reel tape recordings and bought some of them from second hand sellers. My problem is, one of my devices (Revox B77 MK II) slows down both while recording and playback when exceeding the half of the reel band. Is there anyone experiencing such a problem and can help me. Thank you.

Hi peeps, can someone please confirm that I can replace this old capacitor (from the power supply of a Wurlitzer organ):










With this newer one?








And that I just need to assume all four pins that are part of the aluminum sleeve of the old capcitor are the negative end?


Thank you!




- Ofir



.
.
.

So I'm having a bit of trouble with getting any sort of useful output from a Fountek NeoCD3.5H ribbon tweeter (transformer-coupled) in a 3-way design. Just free-air testing the crossover design (shown below) revealed that the midrange is not attenuating at all (passing even 12-16kHz tones without attenuation), and the tweeter output is far less than expected.



The crossover design is a Linkwitz-Riley 2nd-order 3-way with a 6-7 ohm woofer impedance, 8 ohm midrange impedance, and a 7.2 ohm (flat in the usable range) impedance for the tweeter. The drivers are:

Woofer - Dayton Audio PA380-8 15"
Midrange - Fostex FE166En 6.5"
Tweeter - Fountek NeoCD3.5H Horn-Loaded Ribbon Tweeter





I've tried everything I can think of, hence why I'm here. I know it's probably some big, easy-to-spot type of thing, but I'm the type of person that "loses" his keys, only to have been holding onto them the whole time.

Cheers,

-Kev

Has anyone an idea about the acceptable noise of the M4?

Measured directly at the XLR output, I measure around +- 8mV when the device has started up. This does not change when the computer is on battery, the USB externally supplied, or even USB-cable is conneted only by an high quality PSU.

M4NOISE1: USB supplied by high quality PSU, before M4 has compeletly started up
M4NOISE2: USB supplied by high quality PSU, M4 started up


Therefore, I would consider the noise coming from the M4 itself.

Any suggestions?

Many thanks in advance

Michael

Does anyone happen to have an amp like this? It is a Diamond D3 800.1 Q523 is blown, does anyone happen to have a part number for it. Thanks in advance

Hi,

In my hunt for a vintage alnico speaker, for a small valve amp project, a colleague has kindly offered the speaker from his 'old' guitar amp which was scheduled for disposal.
On plugging and testing the amp before dismantling it, I was confronted by hum, hiss, sizzle and apart from immediately powering off, only lots of turning of the volume, treble and bass knobs revealed the following:
-treble and bass pots had absolutely no effect on the audio output, or if it did
it was not audible to me.
-the volume pot only worked to about 3 o'clock and the amp went quiet thereafter.
-slow turning of the volume pot could locate a 'sweet spot' where the output was clean and with an almost valve like presence.

Unplugging and removing the chassis was straightforward, so I immediately got to work replacing the pots, using what I had in my spare parts bin, after which very little sonic improvement was achieved.

Since the markings on the chassis indicated assembly date as being '1973-or 1978' the last digit is not clearly visible) -I recapped the board - replacing all the electrolytics, which was a relatively cheap and affordable exercise.

The amp sounded good after the recap - but the little else changed re; volume, treble bass and output noise.

I do not have schematics for this amp which is identified as a Made In New Zealand Alron 1600 50watt guitar amp.

If anyone has the schematic, experience, information or any suggestion to help rejuvenate this piece of vintage equipment, it would be appreciated as I would love to retain this amp as a backup.

Thank you.

Quite awhile ago, I bought plate transformers to HV for paralleled 6DJ8, 6922, tubes at a reasonable price, (I could afford them). They are frame grid tubes, like the 8417s. I have PPP Bogen amps sitting on the shelf for some time. Do you think they would make good driver tubes? I've had 8417 amps before and liked them, and amps with 6922, or 6DJ8s, but never in the same amps. Maybe drive a paralleled tube into the cathode of another 6922, using the 2nd half of that tube as a splitter. I know, "try it and see if you like it." Good advice! However, I retired and really went to work on our rentals, and audio time I THOUGHT I'd have, vanished. I suspect I won't be soldering at 130 years of age, so I am grateful for any timesavers. Anyway, I know audio constructors have strong opinions on this preamp tube. Some say it's not designed to be an audio tube, and unsuitable. Some like like this tube, but others do not. If you wouldn't mind sharing a VERY few words from experience, I would genuinely appreciate it! Thanks in advance for your time, and good luck with your projects!

Hi Dave, this question is for you. I currently have my TAD 1601a woofers in sealed Parts Express 77.87 liter knock-down trapezoid cabinets that were given to me, and are way smaller than the 113lt to 307lt cabinets recommended by TAD. With notification yesterday of being furloughed this Friday, there's no way I'll now be building suitable cabinets for these anytime soon as I had hoped.

In thinking out of the box, no pun intended, I was wondering if I could improve their sound by a simple modification. Even though it wouldn't increase volume, it would be easy to cut a slot along the sides in the back and then add side panels by adding furring strips and beveling the resulting openings as seen with miniOnkens.

I know, it sounds crazy and probably a waste of time. Your thoughts?

I'd like to find a seller inside the EU if possible. I'm not interested in 6-7N wire, OFHC is fine for me.

My Alpine mrp f240 amp, has no audio when the car engine shuts off and turns back on. The power light is on, 12.8-14.5 volts is at the remote and battery terminals. When this happens I have to disconnect the B+ from the amp for a few seconds and then reconnect, and the audio comes back. Has to be done with the radio on. Please help as this is sometimes frustrating to do, Everytime the car has to be started

Add a band to parametric equalizer Rod Elliott Project 150

Rod Elliott's project 150 shows schematic for a single band parametric equaliser.
Parametric EQ




How does one add another band to it?

Thanks,
WA

I built it with el84 tubes wired ultralinear and 5ar4 rectifier. The power transformer is an Edcor XPWR008. What would be a good fuse amp rating for testing? If testing goes ok what value fuse would be good for long term use?

To me this amp was a more difficult build than the two sse's I have built because of all the connections, more output tubes and transformer wires, so I am trying to proceed with caution.

I did not put the feedback caps in place yet as I am not sure what they do or if they are needed.

The output transformers are Edcor CXPP25-MS-8K/23% which have 4/8/16 ohm taps. I attached the feedback to the 8 ohm tap.

Any tips or comments would be appreciated.

I put it in a pessant 3u chassis from diyaudiostore. Here is a photo:

in my new listening room my tweeters does not sound right, they sound dull and lacking in sparkle/air/life, dispersion is simply not sufficient. so i tried a pair of small sb19st's and that was a relief, but there is always room for improvements, so which is the best 19mm tweeter in your mind?

I'm buying a whack of parts to start experimenting with chip amps. The 8406 I want to try both in class D and class AB. The others are class D only.

However for Class D, i'm having trouble determining specs for the filter.
Data sheets claim full LC filters are not required, and you can make a ferrite bead filter, then goes on to say you must take care selecting a proper ferrite.
How do I pick a proper ferrite? Is the lack of a suggestion just a cop-out so that if your design fails emi testing they arent to blame?
I was looking at using some 150ish ohm @ 100mhz ferrites and the 220pf caps suggested on the data sheet. Is that good enough?

I've read so much at this point I feel like im on the precipice of understanding the requirements of the filter, but i'm not quite there.

Also I dont understand spice so I cant simulate.

Is there a rule of thumb? I've found that the angle about 7 - 8 degree generally works well at least with using first order filter with the mid situated just below the tweeter on the baffle. For my case, the measurement was done at between the mid and the tweeter.

I supposed if you measure on the mid axis, then the angle might be different.

Used these for a test for active speakers. I have 9 of these modules. 8 are used for the test; 1 is never used.

I will let them go for 15 euro each.

not sure if this tester works, i found it in a collection of old stuff and thought i’d try to sell it for a friend. i’ve noticed they are used by people on diyaudio.com and also some guitar forums. i plugged it in and switched the selectors around, no smoke so it possibly works fine? missing two knobs and the original wood case. manual is included. get yourself a deal?!

shipping from Westby, WI or pickup on the spot is also fine.

-David

tube tester - B+K model 607 For Sale - US Audio Mart

I recently got out of storage; put on new power cord and cleaned the push button switches; the unit worked fine until it got a little warmed up then loud cracking static comes out of left channel which cannot be volume adjusted at all; comes through headset as well so not the speaker connection; what is this noise coming from. mj

I have a pair of Polk T15 speakers with dead mid/woofers. They aren't worth buying replacement speakers for them, I was using them as test speakers, but has anyone reused these with anything different inside them? I know the boxes aren't high quality but it seems a shame to toss them out.

Height 10.63" (27 cm)
Width 6.5" (16.51 cm)
Depth 7.25" (18.42 cm)
(1) 5.25" (13.34 cm) d (Round) Dynamic Balance mineral filled polymer composite cone driver - Mid/Woofer
(1) 0.75" (1.91 cm) d (Round) Dynamic Balance silk/polymer composite dome - Tweeter

Hello,

I wish to built 2-way active crossover with 1300 Hz cutoff frequency.
I have theorical schematics, please see Figure 5 and 6 in link bellow:
AM Active Crossovers

But I don't know how to calculate all components nominals.
Maybe someone know equations or maybe can calculate these values?


Best regards,
Tadas

Can I change the cabinet size from 6" face X 9"h X 8-3/4" depth (this is the overnight sensation design size) to.... 6" face X 13-1/2"h X 6" deep...without changing the performance of the speaker? This different size keeps the same internal volume & the same face baffle width.

Also, can the port be moved to the front?

I've been thinking about changing my amp from Sovtek 6B4G tubes to 300B tubes by bringing filament voltage down to 5v and using a tube adapter. The key here is that the Sovtek 6B4G can be pushed much harder than a NOS 6B4G, which was actually a paralleled triode inside the envelope. The Sovtek is a single plate and has been claimed to really be a 300B in an 8 pin base and a higher filament voltage. Maybe the original 300B filament could take the higher voltage anyway without any ill effects. My amp was running with these somewhere higher than a 2A3 operating point and at the low end for a 300B.

So, as I'm looking at 300B tubes I've read that the Genalex tubes are considered a decent tube among the lower priced 300B, all being relative of course since 300B tube prices are astronomical. Then I started looking at the online stores and look at the pictures and it struck me. These tubes are the exact same construction as the Sovtek 6B4G that I already have. They are both made by New Sensor, which I kind of knew, but it hadn't occurred to me that these are really the same tube. One other thing I noted is that these tubes sometimes have OTK markings, which was believed to be a military inspection mark, but when I looked it up using my newly learned Cyrillic skill it just means "inspection station", not necessarily military. It is surprising to me how much I can understand of Russian just because I can read the script now.

So my guess here is that they are branding these to be a higher quality version of their 300B, but is it just branding? Do they select certain tubes to be higher quality, do they build them better, what exactly is it that they do? If all it is is the branding, 6B4G are much cheaper by at least half and I'll stick with them. I'd love to get a quad of the premium types like the EML or PSVane WE copy or Shuguang Treasure, but that isn't happening. $$$$.

Anybody with experience with these tubes care to comment?

Hello fellow DYI audio members,

This amplifier is one born out of social distancing boredom. I always wanted to take a shot at designing a class A2 single ended 300B amplifier. The attached schematics is a works in progress that I will plan build to build but I thought I would share my design as it stands and ask for some suggestions on what might be done better. A number of DYI members have offered great insights on how people might do things better on other projects and I am hoping to harvest some of there thoughts on my bordedom project amp.

Thanks Mickeystan

I’m building a small single ended zero feedback amp based on 6L6GC tubes.
The goal is to achieve as low noise and hum as possible - after experience with commerical kit using 6L6GC where some noise is still audible (with my 98 dB horns) - 6L6 SE Tube Amplifier Kit 10+10W (Stereo)_Power Amplifier Kit_Tube Amplifier Kit_Analog Metric - DIY Audio Kit Developer

Obviousky I will pay a lot of attention to ground loops, placament of transformers etc.

However one key decision is which circuit to build to achieve minimum noise too.

In general I found two different concepts for the driver stage:

1. simple with a single triode - eg:The 6V6 Marblewood Amp | Cascade Tubes or DIY Single-Ended (SE) KT88 / 6L6 / EL34 / 6CA7 Tube Amplifier

2. more comples with “SPRR” and two input tubes -eg: DIY Tube Amplifier Kit 6L6 + 6N8P Single Ended Tube Power Amplifier Kit | eBay or 6L6 SE Tube Amplifier Kit 10+10W (Stereo)_Power Amplifier Kit_Tube Amplifier Kit_Analog Metric - DIY Audio Kit Developer

What is the benefit of going with more complex driver stage (2)? Linearity, frequency range? Does it also help with noise?

If I go with the simple driver stage using a single triode (1) is there an advantage if using a selarate tube for each channnel? 2x 12AX7 while only 1/2 will be used for each of R and L channels? Will it help with crosstalks?

Thanks

Is there any reasons why the signal to the XLR outputs is not taken from where indicated on the schematics?

Has anyone found a good replacement for these ?

I have an mtx amp to fix and the outputs are blown

Hi

I recently tried to get back into playing vinyl records. I have two turntables:
- a Rega Planar 3 with a Goldring cartridge, I think it's a 1020.
- a Bang & Olufsen Beogram 5500 linear tracker with MMC-4 cartridge and new stylus (professionally fitted to the existing shank).

Both players are old but the stylii haven't been used much; in the case of the Rega, I bought it new many years ago and it hasn't seen much use. The B&O has a new tip.

The problem I am getting is that every LP I've tried sounds like the styluses are worn. However, it seems likely there is some mould on the record surface causing this. Is that a "thing" with old vinyl? Although the collection has been stored upright indoors, the room it is in has had some damp issues and the sleeves smell a bit musty.

Any advice?

Hello all. A friend gave me a pair of Focal drivers: 6w3252b. Discontinued way back. Looking for TS parameters, and/or, designs out there for a 2 or 3 way.
These are old, but brand new.
Thanks all.
Stay safe.

Hello!


I have a Technics SA-424 which I lake very much because it has a build-in AM/FM receiver with analog and digital metering.


The issue that I experiencing is that I lost the ability to select from the preset channels, to tune and also I've lost the LCD output.


Long time ago I’ve started to check the machine I made some replacements.
As you can see at the schematics on E section (main amplifier circuit) there is a spot which is the power supply for some parts of the system in between of is the supply of the C (FM/AM preset tuning circuit).
For the pin out 17 to 23 I couldn’t take the measurements that I should have.
The replacements that I did are Q703,704 with the original 2SC1815 (just for renewal reasons),
Q703 – 2SD880 with a BD241C (which I believe that it is not the correct I will explain later),
all the electrolytic capacitors C708,709,711,712,713,716 and the diode D712 -svdsr1k2 with a 1N4007.


Then I had assembled again the parts and I fired up the amp. I saw for a few seconds light on my monitoring but right then I lost it.


So after farther reading I realized that when you try to fix a Japanese amp circuit is not a so easy.
I have some doubts regarding the Q703. The specs says that I should have a rank of Y or O and the BD is a C. Watts more is that I am not sure if the electrical characteristics are similar.
The same situation for the 1N4007 which I believe it should be the 1N4007 but I am not sure if it maters at all.


Can somebody guide me through this?


And one more thing… When I measure on pin 36 I have 36V AC. When I measure on D711 at anode I have 2,5V dc. Is that correct?


Attached the schematics

For more detail the service manual is at Technics SA-424 - Manual - FM/AM Stereo Receiver - HiFi Engine

Hello everyone!

I bought a Peavey PV8 mixer and it has a weird problem.
It plays a high pitch whine when I'm trying to record anything with the mic.
I've checked if it was a ground issue, but even when connecting to the laptop on battery, still does it.
The behaviour is very weird, it allows me to listen clearly to anything on my computer just like my regular interface, but when I try to use it to record, the whine starts playing.
To me seems like an issue with the "ADC or USB" part of the mixer, as the beeping always starts after the program starts recording, an not by pressing or turning any dial in the mixer. Changing some ASIO4ALL settings also makes the whine intensity change.
Any suggestions on what could be the issue?

Thanks in advance!

Is there any product that is capable of capturing NON_AUDIO spdif streams? I want to capture ac3/dts 5.1 over spdif. All the devices I have tested mute the input if NON_AUDIO bitflag is set, which it is with ac3/dts bitstreams.

capture devices which mute NON_AUDIO input
ESI U24 XL 24-Bit USB Audio Interface for PC/Mac
M-Audio Audiophile USB

Hello everyone, forgive my bad English, I use the google translator. The subject of my thread says it all. Can someone help me?

Hello all of you,



I've got the forums confused.
I own a B36-MF from 77-78' ish.
Could you help me sim it in hornresp?
Here is the 3d model i made of it:
B36-MF
And a dfx of the horn itself:
Horn B36-MF.dfx




Thank you all




Niclas

This is a thread about parafeed headphone tube amps. It's open for anyone and everyone to join in and add their experiences, experiments, tips and traps. The more the better! I hope for plenty of variety and contributers.

I have AKG K701 headphones, 62 ohms, and have long been curious about a tube amp to drive them. So finally I started putting a few designs together.

Version 1
This used a 6N30 with just a LL1660/18 interstage in 4.5:1. Might have worked into 300R cans but no good for 62R. Needs more step-down. So on to parafeed.

Version 2
Cunning plan was to use a mains transformer 60VA 230/12+12 as OPT giving 9.6:1 step-down. Kept the 6N30 and LL1660/18 as a plate choke with FT-2 0.2uF coupling cap. Cap size could be bigger so will look at that later. This was now well inside the ballpark and sounded generally very promising. I had help from Shoog and others regarding mains transformers. Tried damping the output with a 120R resistor but preferred without. Good tip is to reverse the primaries and use the preferred wiring, and this did make an audible difference. The 60VA size may be unnecessarily large but I just slightly preferred it to a 25VA I tried. Others have used sizes down to 5VA.

Version 3
Plan here was to use the best parts I have, which are a NP Acoustics 40mA amorphous plate choke and a LL1689 OPT in 9:1. This was now better then V2. Sound was fuller and more detailed. Tube was a 6J1P with Rp of 4.7K. A bit high maybe so next step is to try other tubes with the same iron. I have plenty of volume with my DAC outputting 2v, so the 4P1L and 2P29L look like the next ones to try. On to directly heated tubes, so hoping for more clarity/timbre. These will be tried in SIC diode bias and filament bias.

The ‘simple’ part of your boards makes it possible for tube noobs like myself to play in arenas we are normally not comfortable in. To that end I have a couple requests or recommendations for new ‘simple’ kits...

The SC (simple circlotron) or SO(TL) designed with a cheap, readily available tube, 10 tubes or less per channel total(maybe a top cap power tube? I like the look). A mono block design would be great, output in the 25-50 watts per channel range? Designed with a (cheap) commercially available (not custom) PT.

The SSP (super simple pre) designed with a common preamp tube (12au7/12at7/6sn7 etc?), cheap readily available PT, 1 tube per channel, minimum parts count (as simple as is practical) designed for any standard input or output devices. Something similar to the 4S universal preamp on DIY audio projects without the design limitations (the 4S has high output imp, vol pot on the output, single tube for both channels)

The TP (tubelab pre) an uncompromising 2 stage pre (1st stage 6sn7, 2nd stage 300b or ?) refined warm large gain range

Currently I'm using the standard black Dragonfly USB stick to output into an ancient but serviceable Cambridge Audio 2.1 speaker system. I would like something better. I'm also going to upgrade my speakers to something like Paul Carmody's Speedsters and a DIY sub. I've got a few solid state amps I can use, but I'm itching to try a tube amp like the Reisong A10 EL34.

I'm trying to decide between any number of less expensive DAC's. I see folks recommend the really cheap Chinese DACs and there's the Schiit Modi 3.

Are there significant differences in sound between all of these? My primary digital media are FLAC and 320 kbps MP3.

These are the ones on my list so far:
1) L1387DAC 4X Quad TDA1387 Fever USB Decoder HIFI 44.1K 48K 16bit
L1387DAC 4X Quad TDA1387 Fever USB Decoder HIFI 44.1K 48K 16bit | eBay

2) L1387A 8X decode 1969 pure methailles one machine TDA1387 super TDA1541
L1387A 8X decode 1969 pure methailles one machine TDA1387 super TDA1541 | eBay

3) Schiit Modi 3
Schiit Audio: Audio Products Designed and Built in California

4) Topping D30
Amazon.com: Topping D30 DSD Audio Decoder USB Coaxial Optical Fiber XMOS CS4398 24Bit 192KHz Decoder (D30 Silver): Electronics

Hi,

Will I have to tweak the crossover if I add additional dampening using better materials to an existing speaker enclosure?

Thanks

Hello,


I'm building an headphone amplifier/pre-amplifier and I have a question regarding wiring and preventing internal ground loops.
The attached picture is how I'm thinking wiring the inputs and outputs.
The preamp will have two inputs, selectable with relays, a loop out and a pre-amp out, in addition to a output jack for the headphones. The pre-amp out is activated by a relay.
In the picture we can see the pcb with the relaysand the inputs/outputs.


I'm thinking in wiring the gnds of the RCAs together. I'll still use twisted pair to get the inputs to the relays, but won't connect the gnd in the twisted pair to the PCB.
The left and right channel will be common on the relay outputs and will run parallel for some 10mm (will this be short enough to prevent crossfeed?) and then leave the PCB in two places, one to the amp (volume control) and another to the loop-out. The loop-out will have twisted pair just like the inputs, with the GNDs connected only on the RCA side. The RCA GNDs will then be connected to two wires wich will form two twisted pairs with the common input to the amp.
Regarding the output, it will come directly from the headphone's jack, in the form of two twisted pairs. These will be floating on the relay side.


The star ground would be at the PSU. RCA's GND will run to volume control, then amp, then PSU. ouput jack GND will run to the amp (which goes to the PSU as stated before).


Is this good enough?
Thank you for all possible responses, and sorry if the image is horrible, I've tried my best. Right channel is red, left is green and GND is blue! 🙂

I had to remove one of the tonearm bearing screws to rewire the tonearm. Now I have tightened the bearing screw so that I can't feel any clearance in the bearing. I have used a 20mg weight to see if the stylus drops more than 3mm from horizontal position, balance, as described in the manual. My question is how tight does it need to be and which way do I turn the lock nut? (clockwise as the bearing screw is counter-clockwise?)

Thanks for your advice! 🙂

Hello dear
Please help me i want its clear pic/schematic.

I'm trying to eq a set of bookshelf speakers and every time I measure them I get slightly different results, I'm not sure where I'm going wrong. I'm using rew to measure and a umik-1 with a calibration file. What I do is use a chair and a few textbooks to prop the mic up to listening level about three feet away from one of the speakers, and unplug the other channel. I make sure to have the mic set to left if I'm measuring the left channel or right if I'm measuring the right. Is there anything more to it? For example, yesterday it sounded to me like my speakers had a hump in the midbass but the graph didn't show it, it showed it as a dip for some reason. The next day I measured again and it showed up on the graph, confirming what I heard. I really don't understand this and I want to figure it out soon so I can eq the speakers.

Hi All,
I follow this fantastic forum from many years 😀
Now I would like to realize a new project with yours help 😀

Frome some years I have two full-range speaker made with the TB W3-871 loaded in DCAAV, these are the speakers dimensions's and the simulation:




I am very happy from the results.

Now I would like to realize another two monovia but loaded in trasmission line/back loaded horn. First to try another type of load and second to take better care of the design/color of the speakers.

I'am thinking about somethings like this:



The speakers shuold be for a desk, therefore the speakers dimension of the previous image, 400x235x100, should be OK, but not bigger.

Now, the budget for the speakers is not too high, therefore I don't know if remain on the w3-871 or another driver like this.
3" or 4"?
Can you suggest me some speakers in the same price range of the W3-871?

I'am trying to understand how works hornesp to simulate this type of load, have you any guide or tips to start the simulation?

I prefer to simulate and realize my own project, though maybe works worst than other projects 😀

Excuse my bad english, but it is not my first language 🙁

Thank you very much in advance for your time and help!!

hi,
Audio Analysé is a French company from the 80 - who knows some thing about this amp?
i think that today is metronome-technology, but there is no trace back to it.
it has a very good sound, i am looking for the schematics of the power amp!
best regards,
Williams

I have built many F5's over the years but never had a problem like this. On the latest build one channel is acting differently. When I power on cold the offset is around -180mV on this channel, after a minute -150mV after 5min around -100mV, after 30min -50mV. Finally after 2 hours 0mV, then after 3 hours +10mV, after 4 hours +20mV and still rising. I have built multiple identical stereo F5's in identical enclosure and never before this much offset on startup and the offset rise has stopped after an hour or two.

The question is should I be worried? And what could cause this? I have already resoldered all solder joints but that did not help.

Boards and all parts including jfets are official from diyaudiostore.

Hello everybody!



As I am a new member I hope this section is right for my topic and I quickly introduce myself: I am a 40-y.o. guy 😎 from Italy and work on Automation Engineering.


The topic is: I am searching for information about Toshiba 2SK389-GK dual JFET. On Internet I only find datasheets which contain codes -GR , -BL , -V , but nothing about -GK. They have different IDSS values and ID-VDS curves.


Most of all I am searching for one piece of 2SK389-GK.


Thanks in advance!


PS: image of the JFET attached

Browsing the forum for aluminium or iron boxes for DIY builds, I noticed, they are expensive with prices for which one can easily buy ready made commercial quality equipment. This is a blow for any DIY visitors who may be motivated to build their equipment from not-so-welloff backgrounds.

These past few days I encountered several attractive equipment wooden boxes that can be made with a minimum of equipment. I am referring to legacy amplifier boxes like Marshall Model 1986 JMP-50 Bass Amp.

A box can consist of four pieces of wood fixed together in the form of a rectangular frame. The back and front would consist of metal or a combination of thin plywood and metal. I will try to build such a box for my LM3886 stereo amplifier build. The front aluminium panel would hold the knobs and controls and the back would hold the power connector, input connectors and the output connectors. I will also mount a heatsink on the back panel.

My aim is to reduce expenses. Sadly, ready made aluminium boxes with no holes drilled, cost too much for the general DIY individual. Many people are demotivated to spend so much on something they build or make, as the vast majority of people, consider DIY things to be inferior to commercially produced equipment. In fact, I remember several individuals insisting a DIY amplifier will necessarily be inferior to their surround system with a life of 6 years. Don't imagine the best of surround systems around, but commercially built ones with built-in obsolescence!

Here is my latest zither, I have a few before mostly they are easy to make, they are basically a box with a bunch of strings.
Imgur: The magic of the Internet
The sound hole is triangular only because its easier to cut that a round one.
The strings are acoustic guitar stings, the bottom string is a "e" tuned to a "c" , the next 3 are d's tuned to a c,d,e. the next are "g" tuned to f,g,a.the "b" is a "b" and the top c is a top "e" string.The sound is not bad I want to use a much harder wood for the bridge to transfer the sound better.There is nothing special about tuning it to a major C other than if I tuned it lower some of the strings would be too low and floppy and if I tuned it much higher some of the strings would have too much tension on them and might even break.

First off...yes...I'm a *******. "I know just enough to be dangerous" would be an overstatement. If I put a pot at the output of my opamp circuit...do I have a gain control? Or a volume control? Or a variable output impedance control? Thank you all for your patience. ---Tom

Patriarch of one of the more talented musical families we’ve been privileged to be gifted with, Wednesday, at age 85 from COVID-19 pneumonia.

Anyone have any experience with this amp?

EP-100.2SE | Emerald Physics

Reports are that it sounds ‘smooth and tubelike’ mids/highs.

Looking at using it to biamp the horns (B&C DE250 crossed @ 1500hz) on a new build. Sensitivity padded to 98db.

Would that kind of sensitivity be too much up top for this amp.....or even class D all together?

Bucky Pizzarelli has just died at age 94 of the coronavirus. (NY Times) I was lucky enough to catch him once at a jazz club in West Paterson many years ago.

I have a "new to me" C375BEE.

At low to mid volumes, it works perfectly.

At elevated volume levels (I'd estimate in the area of 10W and higher), the right channel becomes distorted (the distortion increases with volume level, and is most noticeable at lower frequencies) and (if pushed a bit further into the audible distortion) will trip the amp's protection circuitry, requiring a full power cycle. I don't think it's an over-temp situation (the amp really isn't getting that warm) so I am guessing there is some detection for DC / clipping / heavy distortion on the outputs and that's what is triggering the protection circuitry.

So far I've eyeballed it, and found no obviously failing caps, although most of the cap brands are straight from the junk list (Lelon, Jianghai, ...) which is a real shame for an amp that retailed for four figures.

I'm wondering what ya'll think. Should I just go through and recap this thing and odds are the problem will be fixed, or does this sound like a failure that I need to diagnose? Any recommendations?

hi everyone , I'm currently working on a powersoft m50q with a blown psu , most of the parts are blown so I can't even see the codes or values , can anyone help with high resolution pics or schematics of this amp or any of the same series or the K series , ill really appreciate it .

Hi everyone, hope everyone is safe.
First of all I am not sure if this is the right 'sub category' to start this discussion. I hope its ok.
I am really intrigued to learn about the design and the digital processing which goes inside a digital audio console. The nitty gritty of it - the electronics design and also how the micro controller/processors would be programmed.
Hope you could direct me to some good reference materials.

Thanks so much in advance for the help

This is just idle speculation but here goes. The Walsh (Ohm?) driver was a huge cone, specially constructed. I've never heard one, but I understand it was quite spectacular. As I understand it, sound waves travel across its surface and launch at different places, shorter wavelengths where the cone's diameter is related to a wavelength I guess. As designed, the waves launch from the "outside" of the cone. Very well. But what if the cone were more of a horn/waveguide: Would the waves then launch from inside the cone? Has this ever been tried? Would each frequency launch at a different distance? That would make time-aligning the speaker a chore, I'd bet. 😱

I have built a phono amp using four 12 ax7. Circuit is grounded grid input, two Class A, and Cathode follower output. The circuit, which is properly grounded to the house and case, is prone to picking noise up from the power line created by other on line components. I recently had a ground noise on one channel. When I unplugged a two prong cord from the outlet the noise went away. How can I prevent this in the future?

Hello,
So I got a TPA3116 2x100w amp w bluetooth from aliexpress:
ZK 1002 HIFI TPA3116 Bluetooth 5.0 High Power Digital Amplifier Stereo Board 100W+100W AMP Amplificador Audio Home Theater|Amplifier| | - AliExpress
And an AC/DC 24V converter:
AC DC Power Supply Module AC 100 240V to DC 24V 9A Power Supply Board for 100W 150W Power amplifier board power supply|100w amplifier module|power amplifier dc|ac power amplifier - AliExpress

I also got some Philips bookshelf 4' bass reflex speakers, 2x50W, 4 ohm, in total everything was about 65 euro, wasn't expecting it to sound good, by I have been impressed by the sound quality and shear volume of sound coming out from these small speakers and amp. I have a Logitech Z906 and used it to listen to music, but these seem to sound better than it, especially since the speakers are two way with a tweeter.

Anyways, that was the background 🙂

Now I am looking for a step up from this TPA3116 amp, I was looking at a more powerful amp. Been looking at the TDA7498E and TDA7498 2.1 variants:
UNISIAN TDA7498E class D audio 2.0 Channel Amplifier board High Power Hifi BTL mono 220w Amplifiers for home sound systems|Amplifier| | - AliExpress

AIYIMA Amplificador Class D Amplifiers Audio Board TDA7498 2.1 Digital Power Amplifier Board|power amplifier board|amplifier board|tda7498 2.1 - AliExpress


Does anybody have any experience with them?

I am also looking for other alternatives, in the 30-50 euro range.

I also found some TAS5630 ones:
new good quality TAS5630 2X300w stereo dual channel High Power Class D digital hifi AMP amplifier board A1 002|amplifier board|hifi amp|class amp - AliExpress

But couldn't find much info about them, so any help would be much more appreciated.

For the PSU, I am thinking of buying another AC/DC 36V transformer similar to the one I have now.