There is a high pitched ringing (~15khz) coming from my system which seems to fluctuate in volume slightly, almost like tinnitus , which I assumed it was after checking on scope and seeing absolutely nothing.

But after checking more thoroughly it is definitely the system, test tones of any frequency show up clear as day, rapidly changing waveforms like music or noise still show up clearly even if the scope cant track them.
How could it be that this noise is not being picked up at all on the scope?

Also I could still hear the noise through the headphones as the scope was attached.

Hi to all!

I just run into a person selling 4 Peerless CSX 217H / 850134 8 Inch Woofer.

Does anyone knows this model? I was thinking of buying them for a diy project... a 3way Studio Monitor.

Hey guys, so I bought a few of these Jab2 boards, specifically the AA-JA32171 2x50 Bluetooth amp board from Sure Electronics.

I emailed them when purchasing to find out if there was any way to get them in Mono without ordering 500 of them. And they said no but sent me this email

"Please kindly understand that there are more than five parts need to be changed for the PBTL mode and all these modifications are finished by our engineers.
It wastes much time so MOQ 500 will be required. Hope that you could understand.
Here is the guidance of how to change JAB2 board into PBTL mode:
JAB2:
1. Change resistors in R6, R21, R5, R23, C26, C21 into 0 ohm resistors
2. Remove 1uf capacitor from C10 and add 1uf capacitor to C18
Maybe you can change it by yourself."

So I figured great I can just do it myself. Now that the boards are here however there seems to be some confusion. R6, R21, R23 and C26 all were empty, so I bridged all of them with 0 ohm resistors. But C21 has a 1 nf capacitor on it, and C10 is empty and C18 has a 1uf capacitor on it.

So I left C10 and C18 alone and put the 0ohm resistor on C21. And while the audio output does operate correctly, I am not getting mono, I am simply getting the left channel.

I have emailed them several times but still have not received a reply. Anybody have any suggestions on how to get true mono out of the board?

hello everybody
few weeks ago i made this lovely small DHT PP with URSS 6B4G Svetlana LogoC
6C4C, interstage LL1660 driven by E80CC , LL1540 splitter driven by E80CC SRPP
sound very nice THD all harmonics 0,1% for 8Watt
THD 1% for 10W so no bad for tube amplifier
E80CC its long life gold pins Philips special Quality very low distorsion medium mu twin triode, here Dario and Haltron made by Philips Hollande Netherland.
also 6C4C are beautyfull and very well built DHT triodes from URSS Svetlana logo C.
5C3S logoC rectyfier, oil caps and electrolithics and choke for HT power supply.
the negative bias on parallel choke 600H 10mA
NP cathode caps, transformer splitter, i now should write down schematics

First off, this will be used for music with no HT duty. A pair of subwoofers will be matched with sealed 2-ways F3 ~ 73 Hz. I plan to cross the subwoofer 200~300 Hz. I can get a sealed enclosure flat pack for 1 cu-ft, 1.5 cu-ft, and 2 cu-ft.

2 cu-ft, Qtc =.71, F3 ~ 40Hz

1 cu-ft, Qtc =.8, F3 ~ 49 Hz: Has a slight .91 dB hump in the freq range of interest. This is the enclosure size recommended from PE.

I think that I will split the difference and go with the 1.5 cu-ft. which is in stock and ready for shipping. Would anyone care to comment on why this won't be an adequate choice?

Thanks

For a long time I have been fascinated with the "circlotron" output stage topology because you can use N-channel devices exclusively and it is totally balanced, unlike quasi complementary symmetry. The downside though is you have to have two floating dc supplies for every output stage. Imagine a 5.1 HT setup! Anyway, a while back I saw this setup in Glass Audio and have been bursting to give it a try. The big advantage is that you can use a single supply for all stages just like in other amp topologies. I did make a small one a while back but wound up a small ferrite transformer and because of the lack of inductance the LF response was not that great, but it did work... So, on the weekend I got busy and pulled apart and rewound an old 120va tranny with 43 turns quadfilar of 1.25 mm wire. I just used what I had and what would fit. Another really good thing is that the transformer doesn't have to have any great audio qualities, it's major job is to transfer dc to the two electrolytic caps that are going oppositely up and down at an audio rate. The tranny is sort of like a double ended see-sawing (teeter-tottering for you Septic Tanks 😉 ) common mode choke. You can make it out of any old junk, just so long as the windings are identical voltage. at the moment I am shooting for 200w into 8 ohms down to 50Hz with a *single* 40v rail. Will post further pics as the project proceeds.

BTW, I refer to it as a Tetrahedron topology because you can redraw it as a perfect 3D tetrahedron with one tranny winding as the top edge and the other tranny winding as the bottom edge. CT's to power and ground. Each end of the bottom edge has a fet source and a cap negative on it. They split to opposite ends of the top edge so each end of the top edge has a drain and a cap positive. Draw it on paper. Looks cool. Great to dream about.

I'm planning to use this board for my VFET 2 and Pearl 2 builds. But I've been unable to find any information or posts for the JojoD8118 v2.0 filter cap board.

I picked up a couple from Variac at BAF a couple of years ago and could use a schematic if anyone has one.

Specifically, I'd like to know, what should the values of R20 & 21 be?

Also, are the 0.1uF caps C17 & 18 snubber caps?

Thanks to anyone who might know.

Need help identifying 4 missing components on this stetsom 5keq

I am trying to build a 3-way standmounted speaker and I have very little if any woodworking skills. Does anyone happen to know a speaker cabinet maker in Houston, Texas area? I looked at the cabinet design and there is no way my woodworking skills or the tools I have, do the job right. Any suggestions will be greatly appreciated.
TIA,
Jit

I am busy with a single ended 12W amplifier design.
My question is how close to the output transformer power rating can one go.
If the transformer is rated at 12W output can one design to that as a maximum?
There should be a built-in margin in the transformer design before core saturation kicks in right or should one allow for a margin? If so, how much margin should be allowed for?
I am constrained by the availability of output transformer options available to me so need to either lower the amplfiier power or find another output ransformer which I cannot seem to get easily.

Hi guys, I'm new here looking for a little help. I have an eclipse 88150DVC aluminum sub(15 inch) and have started building a sealed box but would like to port it, if possible. I've tried the apps available but getting different outcomes cause I'm just not good at them. The box I have has a total of 3.75 CuFt with wood & sub displacements already calculated in. According to eclipse, my box is too big for sealed but have always had better luck with bigger boxes. I'd like to know if some one could calculate port or vent for me OR if I should even port it. I'll be pushing it with a Alpine MRP-M850 amp. Any help is highly appreciated.

Just gone to switch on my trusty Arcam Alpha 8R and it’s as dead as a doorpost. No lights, sound or the initial solenoid click as it powers up. It is bereft of life. 🙁

Swapped the power lead to check that so I’m assuming it’s the power supply? If so is it an easy swap and are they available or should I start dropping hints to Mrs W that it’s time for an upgrade?

Hi i need some help with this amp one output mosfet is heating up rapidly any help will be appreciated

I've attached the photo of the diagram Thiel sent me for the CS1.2, and a scan of the schematic I tried to make from it. I wanted to better understand it.

Are there places where I've made mistakes?

Thank you.

Hello all, this is my first foray into the ESL side of DiYAudio. I have been on DIYAudio for a number of years. Built all sorts of tubed and SS amps (Icepower, Tripath, Hypex, Krell KSA-50 clone, Aleph 5 Clone, etc) and preamps (Aikido, Jfet BOZ, etc), and now want to take a dive into an ESL.

I have acquired a working pair of CLS panels. I should have no problem with the frames (got some good ideas already), but am in need of a little help on the bias / power supply.

First question is what is the voltage on an original CLS? 3kv? Are the power supply requirements any different from what I have seen here if the CLS is a full range design?

I have a few CLS schematics, but they are a little vague on the actual component values. I also noticed there is no Bias control or brilliance pot on the CLS that my panels came from. They also do not have a toroidal output transformer either.

BIAS CIRCUIT
I have two designs I have researched - one is a simple basic power transformer to a voltage multiplier circuit with diodes to get to 2 - 3kv (or higher), or just getting a 20VDC supply (plan on a 20vdc 3.2 amp laptop power supply) and running it to a DC to HVDC converter to do the same. Is one design preferred over the other? I know the original PS for the CLS had the diode voltage multiplier (12 stages if I remember correctly)...I will post some pics later of the one I saw....

Thanks in advance!!

EDIT: Also, thinking of leaving the CLS to do 200HZ and above, and leaving the remainder for a Tympani bass panels...

Hi guys, it's been a long time sense I have participated here!
I follow a YT channel "NewRecordDay" which the host said that the GR Resarch A\VO's are basically "sleepers". Great great speakers that are usually overlooked.

Anybody know anything about this kit? It's an omni design that throws a big soundstage with claims of a "Frequency response is as good as +/-1.75dB". Kit looks really well put together too!

Hi!

I have a BNIB car audio subwoofer - Kicker L7S 12" and i was thinking about modding it with PirateLogic's MFB StarBass accelerometer and EVE module.

The driver is a dual voice coil, rated 750W RMS at 2Ohm.

Here are the specs:

Fs - 30Hz
SPLo - 86,9 dB
Qms - 11,2
Qes - 0,63
Qts - 0,59
Vas - 55,7
XMax - 16,25
LE - 4,5mH
Bl - 18,28

Here is how it looks.



Do you think this driver can be a good candidate for modding? Although i can tell good sounding sub bass from mediocre, can spend hours upon hours toying with EQ, DSP, FIRs, routing audio, etc, i am still complete newbie in electronics. Probably, will be asking a lot of questions here in this thread.

I also have a car audio amplifier with ample power which i can power via 220V->12V converter. Do you think that a car audio amp can be used in this application?

I am building a Synergy horn with Beyma bass drivers and Faital HF driver and thought that this sub with an MFB would couple with these speakers nicely.

What you think?

What would you change/add to the Akitika GT102 in order for it to be improved overall? Personally, I am curious what could be done to raise the WPC over 100, flatten frequency response, and perhaps other sonic qualities that it is currently lacking (I read it was missing some bones approaching top end). Can this chassis be made to turn into a dual monoblock, for example?

Thank you, any sort of advice would be wonderful.

I recently finished my o2 amp build, and after going through all the troubleshooting steps listed on NwAvguy's blog, I'm still having problems.

NwAvGuy: O2 Details

10)Negative Battery Voltage – Check the “-“ terminal of BT2 (closest to U3). It should be –11.8 V and slightly less that what you measured in step 3. If it’s wrong, check D5, D6 and R2.

I'm up to the 10th step on this page (see above), everything else seems to be working, but the voltage between both terminals varies between -2, -3 volts, not the -11.8 it should be receiving. Also noted is that there is correct voltage on the unbranded side of d6, but the lower voltage on the banded side. does anyone know what might be causing this? thanks in advance

Hi
have 2 older sony's here, both have similar symptom, probably been answered many times so here goes
both read disc's, shop soiled, both play throughout discs, the 970 may skip at some point and both skip(backwards) on playback when i tap (gently) top of facia, the 790 is the more sensitive of the two, is it down to not being used in a long time or something a bit more sinister like being 30 years old or so the lasers are past their sell by dates.

[NOT For Help]

Switching power supplies can be implemented in many different ways using different output voltage control mechanisms. The simplest form is a power supply that achieves output voltage regulation indirectly using the transformer principle. In this case, the output is a *multiple of the input voltage.

The general basic operating principle of switch-mode power supplies is the following.

An cored inductor is energised by passing current through it but avoiding magnetic saturation of the core. This stores an energy equal to:
In a cored inductor, the stored energy exists as long as a sustaining current flows in the coil. A switching power supply, turns off the magnetising current and redirects the output to the inductor into the output smoothing capacitors which hold many times the inductor's maximum energy. For the inductor to charge the output smoothing capacitor, it must develop a voltage that is equal and opposite to the voltage on the smoothing capacitor. This forces the inductor to adjust a current decay rate according to the relation v = -L(dI/dt). The fact that an inductor has the ability to adjust to any dI/dt means it can develop any voltage across its terminals. This is what controls the output voltage of a switch-mode power supply. A control circuit is used to direct this inductor energising-deenergising phase, so that, the output voltage remains within the accepted tolerance.

As mentioned earlier, the simplest form uses transformer based regulation and does not use an inductor.

Switch-mode power supplies come in two families: flyback converters and forward converters. A flyback converter uses the transformer as an inductor while a forward converter uses a transformer as a transformer and an inductor in the output section. A forward converter does not always need a transformer depending on the input and output voltages.




* multiple: some refer to this as a percentage

Hi
A few years ago I bought PCBs for a MooseFet pre amp, Boozhound Labs J-fet Phono pre and the power supply board.
The Boozhound worked perfectly but couldn't get the MooseFet to work so it ended up in storage since I didn't have the time or expertise to get it working.

Recently got the MooseFet out of storage and trying to get it going. I think I have found the problem, the round pad for one of the power inputs wasn't connected to rail on PCB so hope I have managed to fix this.

I would like both preamps in same case which I am working on but need some advice on the power side. I am running the Boozhound of a Hammond 186B24 transformer using terminals 5 & 8. Terminal 7 is free which is the 24v required for the Moosefet. I am bit confused here as the MooseFet has 2 power wires going into this but there is only one tap, do I run both wires to the same single terminal or does one of the wires have to go elsewhere?

Hi,

Curious if there is any Nutube 6P1 + Zen HPA hybrid?

I’m looking for that nice tube warmth sound with high power to
drive my planar headphones. HE-4xx and M1070’s. Around 32 ohms.

Or should I just build the Nutube 6P1 buffer and the Zen HPA?
Single unit would be ideal 🙂

I’m currently using Asguard 3. It sounds great but I miss that tube sound.

Hello everyone!

First I just want to say thank you all to the great knowledge shared on this website, it has really made my first diy project fun.

I bought and assembled the f5 v3 boards with universal psu and on first startup everything seemed fine. P1 and P2 set to zero resistance measured over r5/r6 but when i started biasing one channel I read the DCV on the wrong resistors and went to quick, resulting in the r13 starting to smoke. I figuered out the right resistor to read and with the broken channel disconnected from psu i sucessfully biased the other channel to about 0.55dc voltage and let it stabilize with lid on for several hours, no issue.

I replaced the burned resistor on the first channel and turned pots back to zero and reconnected to psu, but on startup both r13 and r14 start to smoke rather quickly even when reading 0v over r5/r6. No other component are visibly affected.

I am kind of stuck on where I should go now, i guess i will start by carefully examine that i put all the components in correctly. Any advice?

Thanks in advance.

Edit: "Mosfet gate resistor" not "source resistor"

Radio frequency signals is an area where I am a tabula rasa as I have never built or tested anything with these frequencies.

This question is about a device which generates ultrasound waves using a piezo transducer. If I am not wrong, such devices use high DC voltages to generate enough acaustic energy. The device in question generates a maximum of 0.6W/cm^2. I would like to use a cable extension of about 1.5m to 2.0m between the square wave generator and the transducer. At present, these are connected with a short cable about 10cm to 12cm long.

I remember there is a rule of thumb in electronic engineering, which states an electronic current starts behaving like a wave, when its wavelength is about ten times as big as a transmission line or metal link. The effect becomes more and more pronounced as the wavelength shortens.

I am asking because an unmatched transmission line, when used with a frequency behaving like RF, can result in a wave whose amplitude increases until the RF generator is destroyed. I want to avoid this from happening.

At 1MHz assuming an electric field tranvels at the speed of light, the wavelength on the transmission line is 3e8/1e6 = 300m. A 2m long transmission line should only be 2/300=0.67%. According to this calculation, successive harmonics of the square wave above 1MHz should have enough accomodation up to 30MHz. For a square wave this should accomodate up to the 15th harmonic. In mathematics, using the first 15 terms in the Fourier Series should produce a good approximation to a square wave. However, this is all book theory: I am more interested in practice whether what I want is possible without destroying the source of square waves.

The cable I plan to use is a flexible microphone cable with a shield and a twin pair. I plan to use the shield as the ground and one wire of the pair as the signal. The other wire will be grounded at source but not at the piezo transducer.

Thanks for your patience.

Hi
I am about to start building a couple of mono blocks using ICE125ASX2 in BTL mode.
My pre amp has XLR outputs.
I am not sure about how to wire the BTL sync pin ( pin 1 ). What does it wire to?
Thanks in advance

regards

Steve

Hi,

I would like to use the same 12V switching power supply for a TPA3110D2-based amplifier and an USB hub. The amplifier board (PUI audio AMP2x15) has both single-ended and differential inputs. It is connected to the headphone output of a monitor and the USB HUB is connected to the same monitor's built-in USB HUB.

My original setup looked like this:



In this case there was a lot of high-pitched, "digital-sounding" noise from the speakers, presumably because of a ground loop created this way. I then changed it to use the differential inputs:



The SGND was not connected to the ground of the headphone output, but is connected to the board's gound plane. In this case, however, there was a different kind of noise (noise.mp3).

If, however, I connect the USB HUB as well, i.e. the grounds of the monitor and the board are actually connected, the noise goes away:



Why does the noise appear in the former case? Isn't the differential input supposed to work with the difference between the signals? Why does it matter that the grounds of the monitor and the amplifier are connected?

In this latter case the digital noise observed in the very first case also goes away, even though some sort of ground loop still exists. If I connect the SGND of the amplifier to the display's headphone output ground, the digital noise reappears:

Anyone have a pic of the output section of this amp ?

I’m looking for a pic of the resistor that sits in front of Fet 5 in the output section

I'm installing an isolation transformer in an old pepco tube amp (this one's labeled Marlin), and i have a question about general approach.

it's my understanding that i want to ground the amp's chassis using only the ground connection on the 3-prong side of the isolation transformer (IX), so it makes sense to me that i no longer want the amplifier circuit to be connected to the chassis anywhere. everything that was previously connected as a ground or neutral plane should be together, but floating from the chassis.

thankfully, there were only a couple of components that were visibly soldered to the chassis, so i used a spare tab on the terminal strip to connect them together.

now i've realized that the 4 inputs are still grounded through the chassis, but if the chassis is only connected to the ground on the 3-prong side of the IX, they won't be connected to the ground plane of the rest of the circuit. i can't find any mention of this separation in the discussions i've read online.

is it ok to have the chassis connected to the neutral on the 2-prong side of the IX as well as the ground on the 3-prong side? do i need to isolate the inputs from the chassis, and run separate grounds to the neutral on the 2-prong side?

I need a lesson on the importance (or not) of the L-W-H dimensions of a sealed enclosure.

I've read in the past about the "golden ratio" but I've seen box enclosures that are "all over the place" since the 1970's

It seems that the more recent boxes have the depth longer than the width.

In the past, I've seen the opposite.

I'm sure it may be a function of the driver parameters? BUT generally what should you shoot for? (and why? -- please teach me).

After all, air is moved with more force from the front and back so in a sealed enclosure it would seem that making the depth longer would make sense.

I'm interested at the moment in building a simple system using the Pioneer B20 full range in a sealed enclosure and I again see dimensions (width and depth) that are inconsistent.

One plan calls for a 10" wide, 6" deep, 40" high?

THANKS.

Hey guys,

I got an ION PA speaker which doesn't work. So I bought a amplifier board from AliExpress.
The speaker has a 15 inch woofer and a tweeter. I would like to learn how to make a crossover for this pair. Here's some photos.
I would hope some of the electronics from the original board can be reused to build a new crossover.

Here is a poll to understand if CCRCC type PSU is useful for people for Class A / Class AB type amps.
Doodle - Make meetings happen

Its in doodle, I am first time user. So sorry if it doesnt work.

regards
prasi

I have a vintage early '60s Magnavox console that we use daily...it's in our living room and more than just casual listening. It's been recapped, I've modded/altered the turntable endlessly, we run either streaming or a vintage CD player also through the tape input, etc.

There are simply not enough high frequencies using the original drivers. I've replaced the single capacitor-crossover with a modern one of the same value with no real improvement. I've posted about this elsewhere and people go down the rabbit hold of questioning sources...what we are playing is often FLAC files from CD rips we've done, or HQ digital, or vinyl.

I hooked up a set of AR-15s directly to the amp and it sounded fine, so I know the issue is the speakers. I removed the original tweeters and pulled a pair of Vifas from an old set of unused Tannoy monitors, and while I can now hear high end, it's just not loud enough compared to the original woofer and mid that are both running full range per the original configuration.

So my question is this; could I - just for the sake of experimentation - safely pull the first-order crossover out of the old Tannoy PBM 8 since it's presumably set for the tweeter I removed from it, and use it to determine the overall impact of adding a more sophisticated crossover to the original mid and woofer?

If so, how would I hook this up? The speakers are all now in series with a single cap between the mid and the tweeter. Could I put the new crossover first, then run what currently goes to the single woofer in the original monitor to both mid and woofer, in series? I don't want to fry amp or speaker so asking if this is potentially a hazard.

I realize this might not be ideal and understand what I need is a specially designed crossover for these drivers but really want to experiment to see the impact volume-wise of having a crossover on the mid and woofer.

Thanks!

Hi, In a previous set up I used Altec 420a as midrange drivers and really enjoyed them. I sadly had to sell that system a couple years ago, I am now in search of a midrange driver with some of the same smooth qualities but at a less expensive in price. Are there any such units you would recommend using between an Altec 416-8a and an Emilar EA-175/EH800 combo? Vintage paper cones with alnico motors are very appealing to me.

Thanks for looking

Friend of mine brought an Orion HCCA 25001 a week ago, of course - blowned.
Long story in short, some guy having no real idea of electronics tried to "fix" the amp and made a mess.

Now I have missing parts, some previous replacements that i'm not sure about, some added components...all of the "goodies" 😀

I've cleaned up the amp and brought it back as much as I could to a factory condition. Power supply section seems to be fine. Output section needs a lot of work.

Few question.

1. At the voltage regulation section there are 3*LM317T and 1*LM337SP at each side of the board. What is the right placement for the LM337SP, because they look rearranged manually ?!

2. In front of each voltage regulator there are 3 SMD resistors - big one 10 ohms, middle 120 ohms and the third is different for almost each regulator and they are all over the place - and yes, i can confirm they have been changed before by the local "tech guy". Where can I find the right values, since I can't find any schematic for this amp ?!

3. There is a small shorted SMD transistor - Q388 right under the driver board, which even with a magnifying glass i can't quite read the markings on it, seems like there is a glue or some kind-a of epoxy on it.

4. At the driver board the marked IC's, are those irs2184s or is it the tl072c + lm211 design ?!


The output mosfets are the original ones - irfp90n20d, 3 of 8 are shorted. I will buy 8 new ones, but i've to fix the voltage regulation section first and see if the driver board has any drive.

There is also something I don't quite understand. There is an ESP BOARD which contains a PIC. Is this PIC used only for troubleshooting and features or it does control the amp, like the PIC's in the brazilian style amplifiers ?

Wondering if anyone has tried a triaxial speaker using a coaxial compression driver? Say a 12 or 15 coaxial woofer paired up with a BMS coaxial CD. Or is there some reason that wouldn’t be a good idea?

Have a Rockford fosgate power tm750x1bd amp. Not shore what happen befor I got it. Had a few output transistors and fets blown already. Replaced all the blown fets. Checked all gate resistors, they're still good and within tolerance. But when i attempt to power up the amplifier, only one particular fet in the power supply section keeps blowing. Happens only when I apply power to the remote. Blowns with in secs. Q4 is it location on the board

I thought I'd quickly share my impressions of the Hypex NC400.

It lives up to the hype. It sounds great. I feel I can definitely hear the difference between it and the TI TPA3255 I've been using.

I do still love the 3255 and think it's an unbelievable amp for the money. My 3255 build cost about $250 with the PSU. The NC400 all together is about 3x the price for the same number of channels.

Another observation.. The NC400 runs HOT. Much hotter than the 3255 at similar output level. I'm actually leaning to adding active cooling to my NC400 build with a ball bearing fan.

I've also got a QA401 audio analyzer and I'll get a few charts with the NC400 vs TPA3255 to satisfy my own curiosity.

I've got the amps assembled and out of standby. However, everything played back is high pitched. Sounds like it's playing from an awful cellphone...

But coming out from the Klipsch towers.

There's almost no bass... it's there when you put your ear up to the woofers but not much else.

When I take the same source and connect it to another amp - it sounds normal. But when I connect the NC400 it's awful again.

Sounds like something isn't wired up quite right.

I'm going from:
DAC to RCA -> RCA to XLR adapter -> NC400 Amp

XLR to amp pins:
Shield, White, Blue

Both left and right channels are behaving the same. Both NC400 modules are affected.

The XLR adapter looks like the photo attached.

Any thoughts?

I am still not 100% if I picked the correct parts as there are so many options beyond what the Arta voltage probe diagram mentions.

Diode I used,

PART: BZX55C4V3-TAPGICT-ND
MFG : Vishay Semiconductor Diodes Division (VA) / BZX55C4V3-TAP
DESC: DIODE ZENER 4.3V 500MW DO35

Blocked

920 Ohm resistor I used,

PART: A129366-ND
MFG : TE Connectivity Passive Product / H4P910RFZA
DESC: RES 910 OHM 1W 1% AXIAL

Blocked

8.2K Ohm resistor I used,

PART: A129365-ND
MFG : TE Connectivity Passive Product / H4P8K2FZA
DESC: RES 8.2K OHM 1W 1% AXIAL

Blocked

Does it look okay?

Thank you,

David.

This is a new driver. SB17MFC35-8. The driver is mounted in a box that currently has no rear baffle. There is polyester stuffing in the box, but it simply radiates to the rear for now. I am using DATS v3.

There is a lot of non-smooth behavior 70 Hz and 150 Hz, and then a bump at 220 Hz. The blip at 1.2 kHz is not surprising, I would expect a polymer cone to have some breakup starting around 1k or so... but what is with the hash down low?

The SB17CAC35-4 drivers I worked with back in February did not exhibit this behavior.

On one level I would like to simply build what I think is probably the best stand mount box available for the MA10P drivers that are on their way to me, the Wooden Design Simple Reflex 0V9. Over the past couple of years I have watched several of Scott Lindgrens videos on box design and am tremendously impressed with the depth of knowledge he brings to getting the best out of the MA drivers. But, I would very much like to have the speakers be significantly smaller than his 17.6L design.
The speakers will be located in a 15X15 foot room with a 9' ceiling and 6'X7' open pocket doors into the adjacent 15'X15' room. Because of a fierplace with a large hearth in one corner of the room and a large L shaped sofa, the speakers need to be placed about 6 feet apart on each side of the hearth and 8 feet from the listening position. They can only be placed about 18inches from the front and side walls. I am currently using Thiel 2.4 speakers with Conrad Johnson solid state electronics and the speakers tend to be bass heavy and overwhelm the room.
I listen mostly to jazz, classical, and folk music; very little rock or bass heavy material, except for some electronic and new age music.
I want to try some quality full range speakers and have built many 2 way and a few extended range speakers using mostly Tang Band 4 inch "full range " drivers. An audiophile friend has assured me that the MA Alpair 10Ps are substantially better than the Tang Bands (which are very nice in some ways but lack the detail and sparkle of a good 2 way).
So I have purchased a pair of 10Ps and am going to build the cabinets for them, but really want something smaller than Scott's design if possible. I have modeled the 10P in WinIsd at 13 L and it suggests that I would lose about 5Hz bass extention. However , having watched Scott's videos, I think there would be other, perhaps very significant, losses in performance because of the numerous design features of his Simple Reflex 0V9.
The obvious answer as to what to do is, "Just build Scott's design", but aesthetics are important and I would really like a speaker that is no more than about 8.5" wide X 14 tall and 11"deep.
So, If you Mark Audio afficianados can suggest a proven 13L or smaller cabinet for my drivers I would greatly appreciate your input.

Best,
Jay

Looking for a pair of interstage transformers 15K:600 or something like that.Need this for output on my 26 triode pre.

FOR SALE - IMPASSE PRE-AMPLIFIER.

This project is complete and is fully functional.

I decided to go down a different route as I finished it so it has never been used.

There is a slight issue with a bit of hum which will need to be addressed. Information at the time suggested that the HT wiring from the PSU to the pre-amp board should be twisted pair but I never got around to trying that.

Carriage is from the UK and will have to be agreed upon before sale.

My preamp (Rotel RC-991) has started to fail recently; a quick look inside told me all I needed to know. Leaking capacitors and a failing pot/opamp (left channel significantly lower - deoxit was no help). I thought to myself I'll order replacements and fix it. Then I thought, perhaps a new one. Then: perhaps I'll build it myself... I'm currently building my first DAC/DAP so perhaps this is a great goal! Bonus, I can make them look the same.

I wasn't expecting the world I just put myself into, actives, passives, attenuators, relay-switched resistors, rotary encoders, tubes, opamps... well it's been quite a learning curve.

Not sure if I was ready to actually build the thing, I started looking for prebuilt boards. I came across Twisted Pear and am considering the Joshua Tree attenuator as well as the Retro RIIA stage for my turntable. Then I realized these are likely to have very different outputs so I'm now considering the Neurochrome Universal Buffer after the attenuator. On top of this, I'll need an input selector as well. My DAC will have balanced and unbalanced outputs and the turntable is unbalanced only.

So, here's the question. Does any of this even make sense? Am I tackling this the right way, or should I be looking to build something myself instead?

At least for now, the preamp will be paired with two Rotel RB-980BX power amplifiers in bridged mono, my custom DAP and a Project Debut Carbon TT.

Thanks, and apologies for the totally newbie questions!

hello everyone, I have a bit of known audio components, double c core transformers, capacitor resistors, accumulated over years of testing and experimentation, I would now like to assemble an audio note kit l5, would anyone be available to provide me with a schematic? I'm also available to pay for it.

Hi

I have two pairs (unused) FU10RB drivers for sale.

$75/pair + shipping or $140 + shipping for all of them.

Thanks

S

Items are located in California (can pick up in Sacramento or SF)

HI

Looking to buy a pair of Seas FU10RB 4 ohm drivers in good condition

I am located in California

Thank

S

I have built an Aleph 30 that sounds greats and play loud my 4ohm 87db speakers and the volume for my room is plenty enough.
Someone of us has never compared Aleph 30 to F4 or F6 sound?
I'd like build another amp because built is also fun but I'd liy build an amp that is not whorse than my Aleph.
Thank you!

Hello everyone! This project is my first time with dual power supply so, before i start to modify the amp and eventualy be disapointed (or worse, start a fire.), i prefer asking you if improvements are needed on my schematic. Thank you in advance!


[Edit] Typos on the schematic, C3' and C7' 10nf.

Hello
This is Sreenath, and I am currently facing a problem where I build my own amplifier based on Tpa3110 - Power Limiter, (as on Datasheet). But somehow after all soldering when I connect the amp to VCC 14V, there is no sound and the speakers does not provide any Output.
Please give me a solution what is wrong with it.

Thank You
Sreenath C.

**Schematic Diagram and Pcb Layout Attached.**

hello everyone, I have a bit of known audio components, double c core transformers, capacitor resistors, accumulated over years of testing and experimentation, I would now like to assemble an audio note kit l5, would anyone be available to provide me with a schematic? I'm also available to pay for it.

I've been reading every thread about SSE and have a question on Power trans here are two from Edcor.
1- XPWR222 Power transformer for a 120V, 60Hz. line to 750V (375-0-375) at 350mA center tapped, 6.3V at 6A and 5V at 6A. ? is 350mA to much.
2- XPWR033 Power transformer for a 120Vrms, 60Hz.or 240Vrms, 50/60Hz. line to 760V (380-0-380) at 200mA center tapped, 6.3V at 5A and 5V at 3A. I've seen others using this one but having problems with the 760V (380-0-380).
I'm looking at KT88, 90, 120 outputs, if the first one will work then the voltage will be better. I'm going with choke no SS and putting CFB and mode switches in, I'm using High efficiency speakers 35Hz to 20kHz, 92dB.
These are the OPTs I'm looking at GXSE15-5K - 15W, 100mA, Screen/Grid Tap 40%, Frequency Response 40~18K Hz., <1dBu.
Is the 560ohm 5W R17, R27 good or do I need 680ohm 5W, just getting build list made any changes or upgrades you see or know of would be listened to.
Thanks in advance Kevin

Here's a rare opportunity to acquire a set of Oleg Rullit Aero field coil 10" drivers and potentially (if you pick up) some cool bruce edgar back horn enclosures.

These drivers are an entirely different animal than Rullit drivers with vintage paper cones. If you look on that famous auction site, you will see that Oleg lists permanent magnet versions of these Aero drivers at over $4000.

The field coils are powered by 150V and I will include a regulated, linear Lambda power supply.

Also included are a pair of absolutely incredible solid walnut "waveguides" for the Rullits. These really worked a charm with my back loaded horns, giving a boost to the low mids in a way that mated with the natural roll off of the back horns. These were built by a Swiss furniture maker and are things of beauty. You can seem them in the picture of the Rullit in the back horn by the piano.

I'm asking $1750 for the drivers, power supply and solid walnut waveguides.

I'll ship the drivers + power supply + "waveguides" anywhere in the world, but the cabinets are free for pick up with the drivers.

The condition on the drivers and front horns is very good/excellent. The power supply works fine but is an old surplus item (it is, however, worlds better than the cheap switching supplies often used to power field coils these days)

For local pick up with the drivers, I'm also offering a choice of enclosures free. These are not graded for condition, but I would say they are "fair". Note that the purchase price is for the drivers and front horns for them; you get the enclosures if you can pick 'em up and get them out of my garage.

The first is a set of Bruce Edgar designed back horns built out of a very curved laminate of wood and fiberglass. They are very heavy and you will need to pick them up. The JMLC horns in the picture are neither included nor available. The pain on them is automotive high gloss, but it was applied by yours me, so it is only so so. Another sanding and coat...

I've also used these horns with Lowthers and Voxativs + adapters. They work great, and they are configured so you can take the top off and access the throat and back chamber to make adjustments.

The second is a simple 50L plywood box, which is nicely finished on the sides in walnut veneer. You can't see the sides in the picture.

These later boxes aren't really worth anything, but you can have them.

The Edgar back horns are very special, but you have to pick them up.

Please reach out with any questions.

Hi! I'm planning to upgrade the sound system in my car. Since my car is a Mini, I already have very limited space. I'm leaning towards getting rid of the rear 6.5 speakers and putting in a pair of these: Tang Band W6-2253S 6-1/2" Low Profile Subwoofer

Plus, to me having rear speakers makes it sound muddy, I like my fader set to the fronts only. How bad of an idea is putting those subwoofers in that location? I know there's not much airspace, so I'm wondering if they'll actually hit lower frequencies at all. I don't want "thumping" bass. I just want it to sound "full" and I want to be able to crank it up to a reasonably loud level every so often.

That's my other concern, the sensitivity of these subs seems pretty low at 80 db/ watt. I will of course be powering these with an amplifier, and will make sure they get atleast 100w per sub. Will these still be too weak for a car environment? Should I look for something more efficient or a higher power rating? Like I said, I usually listen at moderate levels but like cranking it up occasionally. The stock h/k speakers in this car were "crankable" enough for me but sounded awful.

Hahah, how crazy is this, rght!?!
Well, I simply don't have time to build a new cabinet.
But I have an incredibly well built tower cabinet that I can re-purpose.
The problem is, it has one flaw.
It's got bottom-to-top resonance!

I dont know how I overlooked that when I built it.

Anyhow, my new speakers require a much, much smaller enclosure volume.
I will be crossing these over at 80hz to a subwoofer.

So I want to take 22" of height away from it.
But, from the bottom. Because I need the overall height or I'd have to make speaker stands.

At first I thought I'd just fill it with concrete.
But it seems that even just 1.5 ft3 of concrete is a massive undertaking and a couple hundred pounds.
I had no idea!

Can anyone think of a way to reduce the internal height and volume?
Some sort of liquid, like plaster of paris, that could be poured in the bottom and then would harden like a rock.

For sale: a selection of RPi HATs some in cases with attached RPis. Freeing up some space as none of these are ever used!

1 x Allo USBridge clear acrylic case - 100 GBP
1 x Mamboberry LS DAC+ - 40GBP
1 x Ian Isolator Pi - 30GBP
1 x Ian Isolator Pi / Ian Isolator DoP to DSD converter - 50GBP
SOLD 1 x Audiophonics I-Sabre V2 ES9023 - 30GBP
1 x HiFiBerry Digi B+ - 20GBP
1 x HiFiBerry DAC+ Pro /Silver Case/ RPi 3 - 65GBP
1 x IQAudio 2015 Pi-DAC+/Pi-AMP+/RPi 3/Case - 90GBP

Hi everyone,

I'm new to DIY audio, so forgive me if I'm misguided from the start. On a rash, late-night eBay impluse, I bought four 15" Eminence drivers that had come from Allen Organ speakers from the seventies. The plan was to use them in an open-baffle speaker that I was building with my daughters, but we've decided to simplify that project and won't be using the big woofers.

They have alinco magnets and paper cones and they seem to be in good shape. The stamps on the magnets say "292-0008 67-7548". The 292 code means that they are 15" subs, the 67 is the manufacturer code for Eminence and the 7548 is the date of manufacture. I've contacted both Eminence and Allen Organ and that's as much information as they could give me.

I don't know Fs, Qts, Mms, Xmax, etc. All of the Allen organs have a 32hz stop (maybe even 16) so they must dig down to a low frequency. We tried to power them with a Yung 100W plate amp in the open baffles, but were only able to produce low volumes.

If I wanted to build a pair of subwoofers with these four drivers, how would you guys recommend getting started? All variables are negotiable: I'd consider cabinet sizes big or small, ported or sealed, even odd configurations like ripole. I assume that I'd need bigger subwoofer amps to power them, but that's fine.

I don't have any measuring equipment, but that may prove neccessary. Again, as a beginner, I don't really know.

Thanks in advance! Any help you can provide is appreciated.

David

Good afternoon.

I have a lot of PCB designs that can be used in the construction of vacuum tube related audio projects. However I want to try something new if permitted which is a dedicated group buy channel on the Telegram platform.



What is telegram?
Telegram is a instant messaging app of Russian origin.Its Ideally suited to managing large groups and has a convenient desktop application that i'm very happy with. I was first introduced to the platform during my time at Technical university in Eindhoven and i'm using it ever since.



The telegram invite link for the group is : Telegram: Join Group Chat




Shipping.


I ship exclusively through DHL and only to EU countries that are part of the free trade zone. International orders outside of this zone are possible but at a premium for filling in the customs paperwork. And only for orders above €50.

You can check the international parcel rates for DHL in this PDF. it is in Dutch but that shouldn't matter much.


https://www.dhlparcel.nl/sites/default/files/content/DOCS/2020_internationale_tarieven_consument.pdf

Payment conditions.


Either bank transfer or Paypal is accepted. For custom designs the cost of the design is payable up front. Rates are displayed in a sticky in the channel. For orders over €50 there is a 20% downpayment required.



Order date: My expected order date for this month is 30 June. Deadline for custom design requests is 27 June. The deadline for shipping is 7 July.



Pcb specifications

The PCB's are FR4 matte black finish, that are ROHS compliant. There is a surcharge for ROHS-ENIG finish.


I will post some examples of PCB's in this topic. I expect people that are interested to instal the app. Its rather cumbersome to use the diyaudio PM system or email.

Hello.
This is the clearance from my last project on the shelf. I'm going to stop building for a long time (I guess) to enjoy my stuff.

For sale a pair of SB34SWPL76-4 12" subs from SBA.
They are new, not tested, not measured, not connected.
They are in their original box. One box opened yesterday to picture content, the other box as it was shipped out from the shop.
They were bought on 27 December 2019 and stored at home. I will include invoice for the warranty (until december 2021)
Their price is like 430 euro the pair + shipping.

I will sell for 300 euro shipped within EU.

Hi, hoping to find some more information on this design. It had a proprietary bitumen damped 12" woofer and a 1,25" Audax tweeter.

The 12" looked through a wide rectangular "diffraction slot" supposedly to enable the heavy cone to extend to 1.5khz with a more even on and off axis response.

Given the aperture size I am a bit dubious as to how effective it was but can find no information regarding any dispersion improvement.

If anyone has information regarding this aspect of its performance.. the design paper by Spendor perhaps, or links to it, I would love to see them!! I understand hifi choice did a review and I think hifi news and may be others. Any links would be much appreciated!

I am building a VTV Octal Preamp. I followed the schematics, and need to figure out what I'm doing wrong. I'm using a Hammond 370BX PT instead of of the 270. Because I need the multiple inputs to wire for my mains voltage of 230VAC.
I have 2 of 370BXs. So I was able to compare them to each other.

Using a Variac & Dim Bulb (40WATT)
Dim bulb will glow a little brighter than I expected because of filaments?

When testing the power supply assembled:
With out Rect. tube: No glowing of Dim Bulb.
Pins 4 - 6 (584VAC)
Pins 2 - 8 (5.31VAC)
Green wires (6.7VAC)

With Rect. tube: Glowing of Dim Bulb. Not really bright.
Pins 4 - 6 (4VAC)
Pins 2 - 8 (1.85VAC)
Green wires (2.62VAC)
A & B leading out of Power supply ( 9VDC)

Michael

I am opening this post to ask the Admins of the forum to disable/deactivate my acccount.

I no longer wish to be affiliated with the forum and have a right to NOT be considered as either an active member or a registered regular user.

I have noticed a steady increase in the level of verbal violence and aggressiveness and no longer wish to be seen as a "part" to this forum.

I asked a moderator to respect my wish but was not granted this simple right.

http://www.diyaudio.com/forums/forum-problems/141244-account-deletion.html

it has been done in the past. I ask for it to be done again.

Alessandro

I recently was given a Jensen DB-E transformer and decided to try my hand at building a simple direct box based on their schematic. I’ve done some basic projects before but I’m certainly not and expert and I’m stumped by this problem. When I plug in a bass with an onboard active preamp, it sounds great. When I plug in a passive bass, there is all kinds of noise. Ground buzz type noise. I have a couple basses that can switch between active and passive. In active mode, great. In passive mode, buzzzzzzzx.

I thought it might be a ground loop issue but lifting the ground has no effect. Only thing that changes it is when I turn the volume down on the passive basses, the buzz seems to get louder. Any ideas???

Hello,


NEWBIE on board😉


I'm building a simple 1 tube preamp based on 5670 tube (see the attached drawing) and would appreciate any suggestion for getting the best out of it.
with any lower cathode resistor than 2K I'm getting distorted output.


Any suggestion from experienced members will be appreciated.
Thanks

Hi Guys,

I'm on my way to build PP EL84 amp based on Audio Note EL84 PP "inspired" PCB available in Aliexpress. It looks like a clone of the ANK Audiokits L1 EL84.

I'm straggling to make up my mind regarding output transformer. I’m looking for something economic, but not disappointing. There are so many options and I cannot make up my mind. I assume the experienced of you can give some orientation.

To start with, EI, C-core and toroids are offered- would you prefer one structure over the others?
Regarding suppliers- I read about Hammond (which are not liked due to their frequency response), Edcor, Lundahl (which are beyond my budget) and many other in between like Toroidy.pl., Triad.
On Ebay I can find old stuff like Siemens Klangfilm and some super cheapos from Indonesia or China.
You got the point… will appreciate any hints. I would like to stay below 100$ per OPT.

Another question- which power rating would be suitable for this design?

Regards,
Aviv.

Hi all 😀

I'm looking for small connectors for low voltage power umbilicals (mostly 15V, occasionally 24V).

I'd prefer options for male and female for both the cable and chassis mount parts so there are no exposed power-carrying pins. I've used XLRs in the past, but I want to avoid possible confusion between power and signal.

I'd love to go for the likes of Lemo, but those are way out of budget at present. I've looked at the usual GX12 / GX16 aviation connectors, but the ones I've found thus far are all male on the chassis mount. The Bulgin 400 series parts come very close, but the need to buy separate contact pins, insertion tools etc. is a pain.

Does anyone out there have a recommendation?

I searched awhile this for this but I would like to control my DIY system from my phone maybe via bluetooth (?) elementary stuff turn on and off equipment. Maybe a few other functions I haven't thought of yet. I have remote control on my dac that takes care of volume and streaming functionalities. I want something more flexible than just another remote control and use from single device. Any suggestions are appreciated.
Thanks.

I put together a home system yesterday with a Pioneer VSX-932 AV Home Theater system, Sony PS-LX5, Hafler DH-220 driving a pair of B&W BM602's.

The problem is when I have the Hafler in the loop (between the HT sys and speakers) it has good audio but too loud even with the HT turned down to minimum.

I started with an older 80's Harmon Karmen Receiver(don't recall the model) in place of the HT sys, and same thing. The Harmon Karmen has some pot issues and decided to swap it out with the Pioneer.

So, does anyone know what I'm doing wrong? Shouldn't I be able to turn down the sound down to low or off? Is the signal to hot from the Pioneer? And why would the HK be so hot using the phono inputs?

Hello, I am looking for a power switch for a Viking 5812 stereo receiver, not sure where to start.

Where do I connect the 220Vac mains on the primary side?

Michael

Hey everyone,

I have a common question with the NC400 and after reading the manual and searching the forum I haven't found a direct answer.

I've received my NC400 amp from Europe but the enclosures were not available so I'm waiting... While I'm waiting, I'd like to make sure that the amps are working OK with the rest of my gear and make sure I wired everything up correctly.

I've connected all the pins, powered it up, and the red LED's appear to be all on. But I can't get any sound. I can hear a very very quiet playback through the compression horn on the speaker if I put my ear up to it.

I'm guessing this is because the amps are in standby due to nAMPON you're meant to ground to the enclosure.

Is there anywhere I can temporary connect nAMPON and get the amps out of standby without an enclosure?

I've soldered on XLR inputs with white, blue, and ground to the appropriate pins. I'm using an XLR to RCA adapter cable for input from a DAC with volume at 20%.

How do I model a port that is flared in both ends (e.g. aeroport) for a simple bass reflex enclosure in Hornresp, like this:





Screen shots of the input parameters would help 😱

Hello,

I am trying to decide on a reasonable number for the corner frequency for the RC of the output tubes(KT88/KT120) PP. I found numbers in the range from 1 to 33.9 Hz - see attachment.
I know the resistor value is basically set by the datasheet. Please tell me a reasonable number for the f3dB frequency.

Edit: there will be no global negative feedback

I got this amp in for repair

The guy said after minutes of use the amp just shuts off .

I had it playing on the bench for an hour with no issues .

How do you diagnose this issue ? Or in your opinions is it in the install ?

I got inspired by all the synergy builds and thought I'll give it a go. Getting the courage would not have been possible without your (Tom, Mark, Chris, Bill, xrk971, nc535 and many more I forgot to mention) excellent work.
I was going to go with synergizing the K-402 horn route, and talked to a local dealer. But it's a no go at $4K, I could buy a lot of driver for that kind of dough.
Just a warning. I'm a total newbie when it comes to designing, measurement and software. There'll surely be some bone headed mistakes and DUH moments. But I'm committed to listen and learn from everyone's experience and expertise.
I'm going to stick this in a corner and hope to go down low enough without a need for subs for music. One 15" for now, dual 15 if needed with BMS 4592 or 4594he.
It's a work in progress, slow going due to full time work and keeping the wife happy with home renovations. Finish a bathroom, build a horn kind of deal
Here's what I have so far, one thing for sure it's MASSIVE!!!

Greetings!

I am very interested in building a Single Ended Output
Transformer-less 45 tube amplifier with the fewest parts possible. I
would be very appreciative if you could either give me some guidance.
Please excuse me ahead of time for ignorant questions but I am still learning.

What is the minimum number of tubes I would need in an OTL design? I
am okay with low power output of 1-2 watts per channel.

I did not think this was possible but in a "Boy's First Book of Electronics" a schematic was provided for a one stage amplifier with only one 1h4 power tube and no driver tube or rectifier tube. Would it be possible to drive the power tubes directly from the preamp in an iPhone instead of using the driver tubes?

Bluetooth Apple AirPods use two separate wireless channels for the L & R channel. What would I need to use one audio source (ie iPhone) and
connect to two mono bluetooth devices (one for each channel L & R)?

Stax headphones use a bias of 230v and 580v in "pro" versions. Is it possible to build electrostatic speakers that use a voltage of ~250-300v?

Stereo repair technician position available in South Florida to persons with signicant professional diagnostic experience.