With all the hair splitting in this hobby is amazes me people buy expensive cable and then put brass connectors on it. Brass is like 30% as conductive as copper. I am surprised they even use it for electrical connectors. You also see phosphor bronze and its even worse. I don't get it..

I bought a bluetooth adapter which I was planning to hardwire into my car and into my stock stereo by feeding the audio into my XM reciever, being I don't subscribe or use XM. Being I wanted it hardwired, I cut the wire just before the plug expected to see 3 normal wires - one being ground, one being left + and one being right +. By normal, I mean a wire with insulation which when stripped would either be braided or non-braided wire inside the insulation.

On this particular wire though, it is very odd. It was very thin, and when I stripped the main/black insulation there were 3 colored wired, but not the usual rubber insulation with a wire inside. Instead the outer color is strained wires and if you unwind it, inside is just a nylon string which I believe gives the wire its pull strengh. Thus it is almost like the outer strands are the wire, but that woudn't make sense since all 3 would touch each other. Further I got out my multimeter and I have no continuity between either the outer strand or inner nylon when touching the plug ports. Not sure if I described it well, but hopefully someone may know what type of wire I have and how to properly wire this.

Thanks

Here I have some parts for the project,asking $50 + shipping,
I also modified the code to support left/right adjustment (removed channel selection)

4xSR2 LDR (roughly matched)
1xPCB
1xRotary encoder
1xULN2003
1xMCP23008
3xPanasonic AGQ20012
4x5LN01C (will be soldered to PCB for you)

I am in Wilsonville and wanted to meet some local DIY audio people. Listen to each others systems and generally do audiophile type stuff.
If you are in the area let me know.

Jeff

First, I'm sorry to rehash an old discussion. But I can't seem to find any current information that's useful.

I recently purchased a Marantz SR5013 for my office; I have my old Pioneer SACD player attached to the multichannel analog input, and my Mac Pro 5,1 (2012) connected via optical.

I have some dsd-formatted music only files on my Mac that I can play just fine (using Pine Player) in stereo, but not in 5.1; after some research, my understanding is that the 2012 Mac Pro 5,1 will _only_ output 2-channel audio.

My first thought was to use a Raspberry Pi; I have one with a HiFiBerry digi+ and Volumio. But from what I've read online, this will similarly output only 2 channel audio via optical.

Next thought would be to use the pi's HDMI output; again, I've read that 5.1 audio isn't supported.

First question: are any of the above assumptions correct?

Second question: what's the most reliable way to play 5.1 audio files to my AVR? An Intel NUC? An Apple TV? A USB-to-Optical converter for my Mac? Grab a BDP-S6700 player to replace the Pioneer?

I'd rather not spend more than a few hundred dollars to make this work.

Thoughts?

Hi all!


I have been building my own mini amplifier system and ran out of inputs. I decided to use an NJM2755 4 to 1 stereo audio switch to increase my input availability.


I have done a test circuit with it, following the application circuit diagram in the datasheet to start. The device works very well when switching. However I have found that with my CD player, Minidisc and DAT the audio is being clipped at higher volumes, only my tape cassette doesn't clip but I think that is more as tape cant get loud enough! I can't figure out why it is distorting. It is being supplied with the required nominal 9V.



I am asking on the off chance anyone has any experience on using this chip (NJM2755 | NJM2755V | 4-Input / 1-Output Stereo Audio Selector)


Here is my amp that I have made and it is feeding into: Customizable 20W Amplifier | Hackaday.io

Trying to create hi-End class D amplifier.

Fully differential structure allows to work the bridge , half-bridge, or a bridge with mono polarity power supply output stage (TAS5261).

Full bridge citcuit prefered, because it compensates for partly nonlinearities in power supply, modulation, inductor. Differential noise shaper further increases the loop gain of 6 dB.

modulator 4 layer 32x60mm
3 FDA THS4131 and comp AD8561

I had my old amp finally die on me. My setup does not work well with a centrally-located stereo amplifier. But I do not have room for full size monoblocks. I looked into the small class D board amps, but none of them sound musical to me. I know of the old Marantz monoblocks, but they all suffer capacitor issues now. I've heard of the small Odyssey monoblocks, but know nothing about Odyssey. I'm just wondering if there are other small footprint Class A B monoblocks I'm not aware of? I would prefer to keep it under $750 per monoblock. I would prefer at least 100 watts per Channel, as one pair of my speakers is only 80 DB efficient. Thank you for any advice!

I have this diagram with an 8mh inductor on the positive line but how do you wire them out into the rest of the bunch?
Is it number 1 or 2? I assume it’s two with both positives connecting out. Not my first drawing?
This is a 3 way and there’s only a 8mh inductor on the two woofers and wired in parallel.

This looks shiny!!! I wanna get my hands on a pair!😀

If the response is accurate this is going to be an outstanding driver. Bit confused about the "Hybrid" magnet system though.....


Audax AM21LB25ALBC 8" Paper Cone Full Range

By that, most commercial (and most DIY?) KT88 based tube amps usually have 2 tubes per channel (or more). Is there something that makes using a single tube per channel undesirable?

I know from a marketing point of view, it is easier to sell a ~75 watt per channel amp (which two tubes per channel give you), but is there something about the tube, design that makes it idea to use with a minimum of 2 tubes per channel? This is opposed to other tubes that are mostly or always used as singles per channel.

Looking online I think there are some random single KT88/channel amps, but seems to be rare and maybe DIY only.

Tek recently published this: Probe Performance and Measurement | Tektronix which is a redo of one of their classic intros. Its quite good judging from what I have read so far and a must read for anyone using an oscilloscope with a probe.

---SOLD---

I was provided two MyRef Fremen Edition Rev. 1.6 PCBs by 'ClaveFremen' (Dario) a few years ago so I could measure the performance of the amp. I've completed the measurements and have no further use for these boards. Rather than throwing them out, I am selling them for the cost of the parts ($85).

As shown in the image, one board is fully assembled and thoroughly tested. The other board is unused and ready for you to assemble it. No additional parts are included. What you see is what you get.

The project BOM can be found here: My_Ref Fremen Edition - Build thread and tutorial
Dario is very responsive to builder questions, so if you get stuck during the build, please post your questions there.

Parts cost is $85. Shipping to the US is $10 and $15 to the EU/UK for regular un-tracked airmail. These days airmail takes 3-6 weeks to arrive. If you prefer tracked shipping or shipping by FedEx/UPS ($25ish to the US; a bit more elsewhere) contact me for a shipping quote. I offer excellent rates.

If you're interested, please contact me by email (add @neurochrome.com to my user ID here) or PM.

Tom

DELETED. Sorry I've decided to end this before it gets started.

Hello Everyone,

I hope someone can tell me what gridvoltage is, used for the EL34 tubes in my Simply two Unison research
I have a guy that I can buy tubes from and he asked me what's the gridvoltage
Can't find this info or a schematic anywhere on the internet so thought asking the experts

Thanks very much in advance🙂

Maikel
Holland

Hi everybody I am from Thailand.

I am here to learning for every speakers DIY techniques.

I had 2 way DIY speakers.
I had been made FE103 backload horn for my friend.🙂

Now, I try to design 3" full-range cabinet.😀

Thank you,
B.

Hi Friends,

I wanted to share with you something I found. It's the schematic of the aesthetically pleasing, but not terribly well received JBL 250 Ti:



What I wanted to point out to you in particular is the extreme use of bypass caps in the crossover design. We may laugh at this now, but as the title of the thread says, this was considered the very height of audio design fussiness. 🙂 Notice the repeated use of 0.01 uF AND 0.0055 uF to bypass most caps. The idea was that the smaller uF, the less likely it was to be inductive, and that you could build a nearly perfect cap this way.

At the very least, in line level audio circuits, the use of multiple voltage regulators, along with local PS bypass caps like electrolytic were usually bypassed by a tantalum cap to balance cost and performance.

Hope you find it as interesting as I did.

Most people prefer the unsplit design. A fresnel is a terrible quality lens. Edmunds claims 5% FL variance on their fresnels. Their fresnels are probably better than most. This translates to a muddy, poorly focusable image.

What about a microlens film for the field fresnel? If each microlens is the diameter of the pixels and designed to focus that pixel's light at a set FL it might make a very nice split design.

http://www.ntu.edu.sg/home/yqfu/PDF paper/031104-JVSTB.pdf

http://rogers.mse.uiuc.edu/files\2003\APL_82_1152.pdf

Thoughts?😕

Hello
greetings can anyone tell me the correct name of this insulator
cant find this in local shops used in a very high voltage amplifier
warm regards
Andrew

hello guys, after many times that I came across this forum I decided to join, I am a fan of car hi and recently also of home.
greetings from Italy😀

Hi,

Can anyone suggest some DIY SS pre-amp kits that include everything? Same level of commitment as the ACA or a Bottlehead kit. You get all the parts and just build.

I came across the Akita kits, but it is annoyingly large (I don't know if it's any good or not). Small and simple. 1-3 inputs, output, that is it.

Or...the Schitt Sys is $50 and it appears it should work for this application (between a fixed RCA out and either an amp or powered monitors).

Context is this is for a computer audio system.

Thanks!

I get a weird action from diyaudio when I click the link from gmail, I get just a part of the thread.

When you click this link I get not whole tread, I do miss the last posts I put there.

https://www.diyaudio.com/forums/cla...odulator-extra-integrator-10.html#post6515306

When I do remove the last #post6515306 on the link I can read it all as normal.

Just never see this before, a other browser did not cure that.

New to me amplifier has some issues with channels 1 and 4. Output is way down on both channels. Need to turn the input attenuation all the way up to get close to balancing with channel 2, same with channel 4 and 3. When bridged the 1-2 channel is way down on power compared to the 3-4 channel. Channels 5 amd 6 are fine.. I am using an DSO and test tones, but it was obvious in listening there is a huge power discrepancy. No distortion though, just low power.

Channels 2,3,5 and 6 all work fine.

I have messed around with the 4,5,6 selector amd that is set right according to the manual for the different configuration I have tried.

I am looking into protection mode this amp uses maybe that is the issue. I think grounding th PG terminal will shut the protection off.

Anyone have any experience with these amps or suggestions on where to start?

It would be nice to find some brochures. There's nearly two hours of Mr. Guss and Mr Karlson in the show linked below.

Hi-Fi Workbench WNCN-FM 3/7/64 (from Roger Russell's collection) with Eric Toline -Moderator and guests John Karlson of the KRC Corporation and Reuben Guss-Argus-X (sp?) Electronics

John Karlson and Reuben Guss on Hi-Fi Workbench 1964 - YouTube

OLSON 1955

https://patentimages.storage.googleapis.com/5a/3a/cf/a8f882dc70f84c/US2688373.pdf

GUSS, 1957

https://patentimages.storage.googleapis.com/b8/24/b4/358d7c77ac671d/US2993091.pdf

GUSS 1970

https://patentimages.storage.googleapis.com/5b/bd/1b/04733c6e266939/US3688864.pdf

Hi all,
So have finally finished my first ever build and decided after some close calls with drunk mates getting over excited to buy a metal grill to keep it safe. I've done some research into different ways on how to fix the grill on and really liked the idea of using magnets to make it easily removable. I have bought a metal grill that fits snugly and was going to stack some magnets to give a little extra space for excursion. The plan is to put the magnets in the nail holes on the driver surround as they fit perfectly and look discreet

My question is, will having extra strong magnets that close to the driver effect its performance/movement in any way? I know the magnet fields don't reach very far but I just wanted to check before going ahead with it.

Thanks!

Hello people ! I need a help to modify the attachment switching circuit voltages in 3 stages for power amplifier Class H tensions rise and decem linearly according to the power demand required at the output stage
This circuit works with mosfets channel and N-channel-P ... would like to replace the P-channel fets for it to work only with channel-N ... if someone can me
help with some tips I'm very grateful ...
*
Best regards,
*
ernovbr

Hello
greetings can anyone help me trying to make this smps just
need some clarification if the PWM AUX transformer primary
inductance is correct on the schematic
warm regards
Andrew😕

Hello everyone,
for a powered subwoofer project I was wondering if it is possible to come up with a Class D configuration directly connected on the mains without isolated power supply.
The system is based on a PFC regulated at 380V, 2 rails are derived from it using big electrolytic capacitors, the 2 rails will be semi regulated at +/-190V.

Of course from a safety point of view the audio input needs absolutely to be isolated from the mains with reinforced insulation and here comes the main problems....

I have think about 2 possible options (see attached pdf):

1) The Class D half bridge power stage will be on the primary side and the
pwm modulator on the secondary isolated side.
The main problem is not the pwm drive itself (possible with a GDT,
optocoupler driver or other) but how to pass the feedback (pre-filter or
post-filter) trough the isolation barrier??
Does anyone has a clue about it?
An optocoupler will be surely too slow and moreover too variable...
How to keep to output offset reasonably low?

2) The Class D half bridge power stage will be on the primary side as
well as the PWM modulator. The amplifier will be a standard class-D
topology (still to decide which one) but with rails as high as +/-190V...
The audio signal can be passed trough the barrier trough a wideband
transformer but what about distortion and sound quality? The transformer
must in any case guarantee the proper distances for safety compliance...
It is probably better to convert the audio in digital, passing the barrier
and then reconvert to analog before reaching the class D modulator.
Do you know any A/D and D/A ICs for audio use which does not need
a bunch of software to control them?

Other questions:

- The application will be subwoofer only, so 20..200Hz at maximum. Which
switching frequency for class D?
I was thinking something around 30..40kHz. Of course the size of the
output filter increases but it is not an issue. Running at low frequency
allows probably to use standard cores like cool-mu of MPP without huge
core losses to manage.

- Power swithes for class D: Since and half bridge class D is basically a
synchronous buck converter with a speaker attached to it; what about
body diodes recovery time....
I will need big 600V FETs possibly with the fastest possible body diode;
Infineon CFD2 series seems promising.
Another way can be by using fast 600V IGBTs (STGW30V60DF for example)
where the co-packaged diode is far superior but the IGBT itself is slower...
Does anyone has experience with class D at such high voltage rails?

- Soft switching: the PFC will be CCM ZVS for sure (design already done for
other purpose), what about making also the class D power stage resonant?
Is it possible? any ideas? It will make a big difference at such high voltage.

- Safety hazards: The speaker will be directly connected to the mains but, at
least in my case, it is inside a 6th order bandpass enclosure not user
accessible. I don't see any safety related issues unless the inputs are
correctly isolated.

Any comment will be highly appreciated

Thank you
ciao
-marco

As an initial experiment for building a new linestage, I just breadboarded a parafeed linestage (6N6p, Jupiter 4.7uf coupling caps, solid state CCS, magnequest iron) and it sounds terrific. Really terrific. Surprisingly so.

As I understand it, the biggest benefit of parafeed over a traditional single feed transformer coupled amp is that it gets the big electrolytic cap out of the signal path, and indeed, the clarity of the amp I built is very good. But, not everyone is building parafeed amps, and in fact in the scheme if things they seem to be in the small minority of tube amps being made. So it seems there must be a drawback. Can anyone tell me what it is and what other topologies might do better?

Hello All,

It has been quite some time since I wanted to make this bookshelf design. I chose the Vifa XT-25 and paired it with the 4ohm version of the Peerless 830875 which is the 830510. I cannot find much info on the mids, but went with what I could find.

Since this is my first "from scratch" build I wanted to keep it simple to start with and go from there if needed. So the XO is just a paralleled pair of caps totaling 15.7uf connected in series with the positive side of the tweeter. With the specs on the tweeter imp being 3.4ohms & the mid being 3.85ohms that should give me a XO at approximately 3000Hz.

They sound pretty good, but I have very little experience "voicing" speakers.

I have no testing setup, but instead want to try and help these be as nice as possible without getting too involved in "testing", if possible. I do have more than a handful of parts to mix, match, and swap out for listening tests to help me develop the crossover as I go, but I simply lack direct experience to start jumping just yet.

They are installed in the now discontinued Dayton Curved Enclosures with replaceable baffles. They are a sturdy design with some heft to them. I also added polyfil to the cabinets that are NOT vented. They are being driven by a Denon AVR-X4500H set to 4ohm and everything seems fine so far.

Any thoughts on what I have done so far? Am I missing something or have I done something to this point that could be destructive to the drivers? Again, this is my first set from scratch so I do not want to do anything stupid that will damage them. I have intentionally kept the volume low until I hear some feedback.

Cheers,

David

This is the black connection fixture in a UREI 813C.
I am trying to identify it so to replace it if possible. Maybe a third party makes these.

Thx

Looking for a good power amplifier, I initially designed and built a "LIN" amp with cascoded jfet input, "buffered TIS", high current drivers and Lateral mosfets outputs that I have been using as my main system amp.

I grew used to its unparalleled low distortion, sheer bass slam and overall musicality.

Then I designed and built a smaller amp with singleton IPS, bootstrapped TIS, ccs mirror loaded resistor as driver and lateral outputs.
This one did not have the same "slam factor" but had some major virtues like improved voice presentation, and much increased microdetail rendering when compared with the LIN amp.
I wanted to have the best of both worlds so I started designing a new very low noise / low distortion singleton.

This time I decided to go the "less is more" way in order to boost clarity without impairing other sonic factors.

1 – Input Stage (IPS)
I am using a single NPN for the input stage.
I chose the KSC1845 with high hFe, able to stand the high rail voltages needed for a 200W amplifier, with very low Cob (does not need cascoding) and a high fT 110MHz.
To minimize noise, I chose to run it at low standing current (0.5mA).
To increase gain the NPN collector is CCS loaded, I designed a CCS able to work with very low In-Out voltage drop.
The collector current drives the TIS that converts it into voltage swing.
The biasing is very simple and I added a second KSC1845 connected as a diode (base to collector shorted) in the circuit to control voltage drift due to temp changes. This transdiode is thermally coupled to the input transistor in my build.

2 – Transimpedance stage (TIS)
The TIS (VAS) is built with two transistors:
The first one is connected as an emitter follower (beta enhancer) that drives the second one acting as the proper TIS.
Miller compensation is set around these two transistors.
The beta enhancer is a BC556B chosen for its very high speed (280Mhz), low Cob (3pF) and high hFe.
The TIS is a 2SA1381 a medium power PNP with outstanding characteristics. It withstands high voltages (300v), high speed (fT 150Mhz) and very low Cob (3pF).
I needed a medium power PNP because I am using it to drive the lateral output mosfets directly (without drivers).
After long discussions with some experts, I now know that lateral mosfets basically need enough current to charge its input capacitance but it is not fundamental to have a low output impedance driver as these mosfets have very high input impedance.
To have the “natural voice rendering” I decided to bootstrap the TIS but to have the fundamental “bass snap” I used a floating depletion mode mosfet CCS as the upper resistor in this bootstrap. (Here I had the guidance from Hugh Dean and also followed Damir’s information gathered here: bootstrapsCCS+T-TMC)

3 - Miller compensation
As I wanted to use a small value for the miller capacitor, I included another capacitor in parallel with the series feedback resistor in order to increase phase margin.

4 – Output Stage (OPS)
For the outputs I chose the double dye laterals from exicon that are designed for 250W each so I could get away with only two pairs, saving precious board space, having larger distances between them for ease of heat dissipation and still being able to design for 200W into 8 ohms.
Biasing these mosfets is done with a resistor fed directly from the TIS.

The amp is terminated with the usual Zobel included to make sure the output sees a resistive load at high frequencies, keeping the open loop gain in control.
The output inductor is there to guarantee the load going inductive at HF. If we drive (long) cables, certain filter topologies, or a piezo tweeter, the load doesn't turn inductive at high frequencies, but capacitive. Here, the Zobel scheme does not work, so I included a series inductor in the amplifier to avoid oscillations.
The resistor parallel to the L is there because a series-resonance circuit is formed by the combination of the output inductor and a capacitive load, which forms a short at resonance. The resistor in parallel with the inductor reduces the Q of this circuit, preventing the short from occurring.

To increase image rendering I built the prototype in dual mono style with one transformer for each channel.
Each transformer has two secondaries that feed one bridge each.

Rectifying and smoothing circuits are included in the amps board so the reservoir caps are near the demanding output devices.
Local decoupling caps are provided and all gnd return paths are independent in the pcb layout.
Capacitor bank size was determined based on the splendid spreadsheet from Thomas P. Gootee.

I used LT-Spice to simulate the design before the build and will provide here some asc files so everyone can also play with it.

Ricardo Cruz

I have for sale 3 sets of Subbu V3 (kit) + Built PSU + JG Buffer (PCB+BF862 FETs) & Matched Fastron Inductors

I'm asking USD$ 573 for them all. Shipping and paypal fee are extra.

I'd be willing to split them if I have 3 committed buyers.

Hi eveyone;

input will be +19 -19 volt instead of 18v.

Orginal Layout


My pcb


They are not the same because pcb complated in 2012 but update relased in 2003. I cound not find a better one.

can tell me, the capacitor voltages & resistor watt on JLH2003 here below;
depends on my pcb.

220UF c2 & c3?
470uf c1?
330pf c10?

Watt value of 10ohm R15 and rest of all resistor 1/4 or 1/8W ?

Thanks in advance.

Dear All

After building the very good sounding HDRP200 explained here:
HDRP200 High speed very low distortion singleton power amplifier

I wanted to try the same simple design but using a Jfet input and omit the input capacitor.

In this new amp I am using a ccs to set the operation current of the IPS jfet and the offset control depends on this ccs stability.

The IPS is now loaded by a resistor R3 (390ohms).
The transimpedance stage (VAS) is buffered and drives directly the output lateral mosfets.

This amp sounds fast, providing a very detailed low end.
Will now finetune it because I feel treble can be ameliorated.

Here you have the working circuit:

Hi. I'm trying to find information on repair and trouble shooting for a KLH model r6200 stereo receiver. I can clearly see a blown resistor. Anyone help? Thanks.

Ok, I’ve been ‘burned’ by two cheaper soldering station failing on me so it’s time to bite the bullet and invest in quality.

Would a Hakko FX888D be a good place to start for a entry-level station?

Regards,
Dan

As title please.
Would like the ft96 so can mount in an enclosure, or similar good quality unit
Thanks.
Graham

Hi all,

I'm a tube guy, I know some SS stuff, mainly simple Wurlitzer EP boards. I'm completely bewildered when it comes to these JC schematics, they're a bit intimidating!



I was hoping someone could point me to the location of the output bias voltages.

Mainly, the issues are subtle crossover distortion on both channels, plus the distortion effect doesn't seem to work. Also on the second channel, there is noise behind the test signal. When you kill the signal, the noise persists for a second and then goes quiet. It may be my imagination but the noise has a chorus effect on it.


The PSU is fine, +/- 43V & +/- 15V rails are making it to each board.

Any tips would be appreciated! thanks for your time

Hello members. Here I am again, always with a question. So...does anyone have experience with a substitute tweeter on the above OPTIMUS LX4 bookshelf speaker? I was hoping for a direct replacement to screw into the existing mounting holes. The Parts Express (paper) catalog used to list drivers by size, mounting etc. If a member has a catalog and would be willing to help me, the mounting distance horiz=3" & vertical is 2 7/16". I enclosed an image. Thank You, civil6.

Hello, I came across these military loctal sockets:
Do you think these would be suitable for 4P1L? I dont think you can fit these comfortably. But woud it be possible to somewhat "modify" these sockets to a standard ones - removing the sheet and making some improvisation on standard mounting?
Thank everyone for your suggestions. Best regards, Michal

Dear diyAudio forum,

I'm in search of the Speakerlab Khorn plans.

Does anyone have them availabe? Preferably in cm/mm rather than inches.

Please e-mail at: simonstareus@gmail.com

Many thanks,
Simon

Hi folks,
don´t know who else could give solid tips when not YOU ...

My problem: I am using a Nemic Lambda SMPS 32 V / 10 A with very pleased
results but the cooling fan works everytime. At lower listening levels its really disturbing. Either it should be cut off or replaced by a temperature regulated cooling fan. But how ... ?

I see two possible reactions of the SMPS when the fan is cut off :
1) the SMPS doesn´t work from the beginning because it´s monitored
2) the SMPS shuts down after a specific temperature

The amp has about 2 x 40 Watts (max. power)

I can upload pictures if someone wants make a look. Any suggestions ... ?

I recently bought the 9 Beethoven symphonies in a 5 CD collection (Anris Nelsons, Wiener Philharmoniker, Deutsche Grammophon). Included in the set was a Blu Ray audio disc with the entire set.

I am building a collection of high res audio files, mostly 24 bit 96k FLAC, but a few DSD as well.

I would like extract the Blu Ray Audio data onto my laptop. I am a bit stumped on how to start. the normal "CD Rip" process I use does not really work.

I have no experience in ripping the video from DVD or blu ray discs... so I am a newbe...

any thoughts?

Hi all,

I would like to ask you regarding the single ended amplifier with EL156. I already have output transformer with Ra 3k5 Ohm instead of recommended Ra 3k8 in the EL156 datasheet from Telefunken / Ua=450V, Ug2=280V, Rk=90 Ohm, first page/. source: https://frank.pocnet.net/sheets/128/e/EL156.pdf
I try to plot the both Ra to the characteristic, but I am little bit confused from the plate current on the characteristic in area where the Ug1~0V. Is it okey, when the anode current exceed the datasheet limit for the cathode current Ik=180mA? Because the cathode current in the area where Ug1~0V will be about 210mA Ia + circa 12mA Ig2. Can be the cathode current limit exceed? Can I use the output transformer with Ra 3k5? If yes, should i increase the value of Rk?

Thanks guys!

PS: Sorry, I am not strong in English 🙂

A pair of either tweeters needed for speaker project.

Simple Software Low-Pass Filter, Does anybody know if such a thing exists?

I've a couple of passive projects on the go and rather than run simulations I'd like to 'know' how the sub will 'sound' before it's finalised. So, I'd like to play music from my computer through a variable low-pass filter to run tests. If I run a full range signal the sub will invariably sound boxy because there's no damping and it will produce resonances and waves using signals it will not receive once a real filter is installed.

e.g.

Hello

Stuart Hawkes and others like Alexandra Stréliski want to mimic the sound of a vinyl with the hiss and pop and surface noises of the vinyl records on their cd recordings.

I've discovered that wen I did buy two cd made by Alexandra Stréliski, see is a good composer and very good pianist, but the sound was bad and noisy with a low resolutions, I have a good sound system, for now I use my Crimson amp, and I use a Adcom cd player and Dynaudio speakers, so I was very disappointed with here cd, so I wroted to the recording studio who did the recording, to ask them if there was a problem with the recording, they told me that Alexandra Stréliski did just rent the studio and she bring here hown technician and that she choose to mimic the sound of a vinyl with the hiss and pop and surface noises in the recording.

The sound of a good vinyl are not so bad, wen I listen my vinyl there is no noise or low resolutions, thoses artists did the wrong choice by adding hiss and pop and surface noises to mimic the sound of a vinyl to their recording for a cd.

Is there many artists who mimic the sound of a bad vinyl in their recording for a cd ?

Any guys who did buy or listen cd done by artists who want to mimic the sound of a bad
vinyl ?

Thank

Bye

Gaetan

Hi,

I have for sale two pairs of PHL 1130 16ohm midrange drivers. One pair has light use £120 and the other pair is new £150
All of them are in original boxes.

I will include UK shipping in those prices. Shipping elsewhere at cost.

PM if interested.

Thanks for looking.

I have for sale a pair of PHL 1130 16 Ohm midrange drivers. Unused.
Purchased for a project but I've now gone in a different direction.

£120 inc. UK shipping

Will ship elsewhere at cost.

There is a simple method using Ltspice to measure the degree of
affectation of our circuit to the presence of capacitances,
thanks to ideal voltage sources, measure the zero crossing time,
we place a capacitor and we measure again, for a simple calculation
this gives the delay per pf of capacitance,
in this way we can evaluate the importance of capacitances in that node. In the scheme that I show you, you can play with different values
​​and measure the delay, the rest is a matter of calculation.
Obviously if the capacitances are not constant and associated to voltage,
neither is the delay of the passage of our complex signal through that level ...





And yea I Know , another nonsense for experts in this forum ....

that is the idea.

Having a great time using my Tubelab SE to drive my Pass Labs F4 clone using my backup Fostex 167E drivers in MLTL speaker cabs. I also tried Tubelab SSE 300B and really like it. Happy listening!

Searched this forum with not much luck on this topic & looked online with no joy. Figured just start a new thread. Here would be the audio signal path from this 2.1 preamp:


Echo Dot - Preamp - Chip amp for the 2-way passive & then for the subwoofer the following from the Preamp:


This DSP low frequency controller Dayton Audio DSP-LF Low Frequency DSP Controller and onto a similar mono chip amp, preferably plate amp, but these are scarce as well, but the mono amps can be found easily enough.



As always thanks for your responses.

What are your thoughts on this amp? See attached schematic. I recently came into possession of this amp, a Classe 70. Since they're out of business and the schematic is readily available, I'm curious as to what you think of the design, which they apparently used on every amplifier basic form and simply scaled it accordingly

The schematic is towards the end of the document ...

PS, sorry for the wrong attachment in the forum posting down below ...

I have an RME ADI-2 DAC FS that i use as my DAC, DSP, and volume control. Unfortunately, it has no 12v switch.

My setup simply consists of ipad pro as source connected to the RME via USB, then from the RME balanced XLR out to my monoblock amps, then from there to my passive speakers.

The monoblock amps DO have 12v triggers.

I need to someone have a 12v signal sent from my RME to the monoblock amps’ 12v triggers when i turn on the RME.

Is there a ready-made part that lets me plug in the RME into it, detects a power draw which triggers sending of a 12v signal via a 3.5mm jack into my monoblocks’ 12v trigger jacks.

if no ready-made available, can a newbie readily build one?

ive seen something by Nile that does this but i think they dont sell them new anymore.. saw a couple on ebay used. problem is it requires a minimum 15w draw to send the trigger signal out its 3.5mm jack. the RME is a lower power draw device.

thanks in advance

Has anyone bought High Performance Audio Amplifier Handbook (Thai)?Is there an english version?

This post is somewhat similar to the one below, where the gentleman is aiming for a world class setup. Except I'm not, just a good one 🙂. I do think we are similar in being more the type to jump right in. I understand best by doing, I have no brain for engineering.

Hi folks. I've been wanting to try my hand at building speakers for a while. I like woodworking, and I like speakers, but in between that I have very little knowledge. I recently got a nad t758 with Dirac, and was really impressed with Dirac and thought maybe this was my chance to try my hand at building something, without doing any crossovers at all and letting Dirac do most of the work.

So while I had previously thought of doing something to use in my main 2.1 system I'm thinking maybe I should build a nice pair of fronts to use in my home theatre, something good enough that I can use it for 2.1 stereo happily, and maybe rival my mains. It seems to me the nad is good enough to really enjoy, if not in the same league as my stereo exactly.

I'm hoping to build a new garage with a listening room, which would make my diy speakers *the* speakers either out there or in the house. So I'm aiming for good.

Sooooo...I guess I'm looking for the most general advice, resources etc...

So much of the info I come across has a lot to do with crossovers, which makes sense, but I'm more trying to learn how to pick drivers and how to make decisions on cabinet style.

Right now I have my eyes on:
RAAL 70-10D Ribbon Tweeter
Totem 6" torrent drivers

I can get both for an excellent price (under $1k usd) and I *think* they would go well together but that's kinda my starting point to try and figure it out.

These, because if the room, would be wall mounted and used with a sub.

Any and all advice is appreciated.

And yes, I know the smart thing is probably to get some kits and play with them. I gotta be honest, I don't really want to. I would really like to dive in to something good, and really get at the woodworking element. I figure the drivers are always reusable in a different design if needed.

I think a Dirac enabled multichannel amp can run a fully active setup just by specifying crossover in the setup menu, yes? Alternatively I could use a minidsp or something similar, but I feel I do want Dirac.

Appreciate anyone who can throw any knowledge at me.

Those drivers, should I pounce on them, or am I an idiot for thinking I can just pick some decent drivers and make them work without fully understanding them.

I'm hoping to build something punchy, fast, dynamic. I currently have a very accurate, musical, pretty system which I love. Midrange magic. I thought I would go for a counterpoint, something a little faster and suited to rocking out. Yes, it is bookshelf I'm looking to build but in my experience a good bookshelf with a sub can give a pretty fun and intense presentation. And its what fits my space.

Pic of my space for reference. Yes the xmas decorations are down now 🙂

My hypothesis is that much commercial (PA) equipment, when driven at much lower SPL, may be cost-effective for demanding domestic use. For example, an 18in JBL 2268H(PL) that is very low in distortion might be safely driven to a more audiophile low frequency limit. It's FR is 33Hz and my two specimens measure half power f3 of 45Hz. They already sound very nice crossed-over at up to 120Hz to compatible 2-way systems, adding impressive reproduction of double bass viols with C-extension (32.7Hz fundamental) and 40in orchestral bass drum. The question is, for use listening at ~16ft (5m) in a large acoustically treated home theater playing at SMPTE standard SPL (85dB nominal, 105 peak, ~108 maximum with all channels of low bass redirected, +LFE), could they be EQd safely and still with low distortion to say 30Hz or even lower?

This thread https://www.diyaudio.com/forums/con...ime-adjust-sound-sansui-silcron-speakers.html appears corrupted while others appear OK. Never seen this happen before. Perhaps it's only temporary.

Selling 3 sets of Tortuga Audio V2 LDR control modules with JFET unity gain Buffers and display modules plus various additional components. Full Tortuga documentation available. I can also provide schematic and Eagle pcb files of the buffer which includes a delay-on. These were part of a working DIY volume control after a DSP crossover unit for biamping and triamping.

Sold: Set 1: Complete working DIY Tortuga V2 LDR prototype chassis with power supplies, two display modules, JFET buffer, Bybee Music Rails, and PS Audio power receptacle. $230obo. Sounds every bit as good as my new DIY Tortuga V3 DIY preamp. Needs Apple remote. Unit has no input selector switch. Inexpensive way to experience the great SQ of a buffered LDR volume attenuator.

Pending: Set 2: Tortuga V2 LDR controller, two display modules, JFET buffer plus power supply for Tortuga V2. $130obo. Needs Apple remote and buffer PS.

Set 3: Tortuga V2 LDR controller, one display module, JFET buffer and volume control encoder pot. $100obo. Can be used for biamping or Bal Vol with Set 1 above or for building a V2 LDR Volume controller by adding power supplies, etc. Can operate with encoder pot. Needs replacement LDR Module and both power supplies if not used with Set 1. Apple remote optional.

Tortuga Audio still sells new Apple remote control modules ($30+shipping) and encoder pots ($23). I can include a used Apple Remote A1294 from eBay and pair it and test it with the V2 LDR controller for an additional $20.

Buffers need PS such as the DIYINHK 4.17uV Ultralow noise regulator +-12/15V 1A plus a dual 15vac secondary transformer. Buffer uses no more than 60ma.

Well hi,

I have this Sadowsky/Aguilar based discrete bass guitar preamp schematic. It is designed for 9V but i want to run it on 18V for more headroom. Now, after i've built it and tested it, i have two questions:

1. Cause it's designed for 9V, it obviously distorts on 18V. What modifications i'd need to make to make it run clean with as much headroom as possible on 18V?

2. This circuit acts as radio receiver too for some reason and has some high pitched noise when Treble is turned up. I can hear stations on it with a lot of noise when signal is not fed with Treble boosted. Am i missing something? Proper shielding/grounding?

Thanks!

A couple more interview videos:

My latest sit down with First Watt and Pass Labs' Nelson Pass - YouTube (part 1)
More with Nelson Pass - YouTube (part 2)

The amp had a few shorted outputs on the high side so I replaced all the outputs, octocouplers and op-amps in output section. Under 12 volts of input I have rail to rail oscillation, once I crack the voltage above 12 volts rail to rail oscillation disappears and I’m left with the following image below. Powersupply functions like it should under or above 12 volts.

Hi

I have been working on an Onkyo A7. I have upgraded a number of these before and sorted out all sorts of problems, however this has me stumped. I have replaced all the electro caps and have the amp working- except if I attach a load (speaker or dummy load) to the output and then it draws massive current. At idle with no load it is about 0.2 amp which seems about right.

I have tested the output transistors and they seem fine (peak transistor tester), and as I am doing an upgrade on this unit I changed out all the main board transistors (all of which tested ok). There is negligible DC on speaker terminals. All the voltages on the main board measure fine

When I put tone in and test at the relay there is signal on both sides (input and output), and the relay works and the associated circuitry measures appropriately.

So I have been looking for cables issues, or anything else, but am I missing something basic?


schematic attached and all help appreciated


Peter

Good night,


I have a AV Receiver and I'm connecting it to my PC Soundcard (Auzentech X-fi Forte 7.1) in 5.1 using the Receiver 5.1 analog inputs (3.5mm to RCA).


I have the following questions:

► Should I set my soundcard as Large\small speakers OR set it in the AV Receiver?;

► Should I set a general Crossover for the 5 satellites in my soundcard and redirect anything below to the subwoofer, OR should I set the crossover in the Receiver?


ps: Attached pics show my soundcard with large vs small speakers (I can also set separately by each set of speakers like in the receiver).

Thank You
guily

Hi.

My next project is replacing/ upgrading capacitors in a Harman Kardon HK980.
I pretty much have the amplifier boards down as to what to replace, but I am in doubt as to what to replace on the MCU board (schematics attached).

I also plan to replace the power supply caps on the +/- 15volts, 5volts and 12volts lines too.

HARMAN KARDON HK980 230 SM Service Manual download, schematics, eeprom, repair info for electronics experts

I hope some you brilliant guys have some ideas. 🙂

Calling upon all residential loudspeaker engineers.

I am considering using the C25 tweeter and C90 midrange, but I am facing a dilemma. The diaphragm's are more or less on the same vertical plane when placed on a flat baffle. Nothing wrong with that per say, but it creates an interesting problem I would like to highlight and potentially get some input on. The issues is dispersion. I know first hand how a well implemented waveguide sounds and it is pure magic for the XO point and transition from midrange to tweeter. Since the Accutons are on the same acoustical plane, to time align the tweeter is never done. I've not seen any Accuton speakers with a waveguide and so, one run into the "issue" of loosing out on that extra level a waveguide offers.

The fix could be something like moving the tweeter and midrange to the woofer's acoustical plane, and give the tweeter a waveguide size corresponding to midrange size (5") and give the midrange waveguide size corresponding to the midwoofer size (6-7").

Anyone out there who have a similar experience or wana chime in ????

****************************************
(While writing this thread, I found one commercial company who did use waveguides with Accuton, namely Audiograde, but their website is for sale, so maybe the business is no longer operating.)

Hello,
I want to build an ELC84 triode strapped (10mA, 250V) line amp using two CineMag S-217D output transformers with a primary of 12.5K (is that plate to plate impedance or just one plate impedance?).
The ECL84 pentode has an Rp of 3000 Ohms.
Is that a possible application for this output transformer?

I have a Wurlitzer 920 piano extension amplifier from 1954 in the shop.

The circuit is not your average garden variety amp. The screen grids of the output tubes are connect to the cathode of a 6SL7, which appears to be connected to a socket on the edge of the chassis. Possibly some accessory plugs in there and completes connections to provide screen grid power, but until I can see a diagram, it's just a guess.

Anyone know what goes in that socket and better yet, anyone have a copy of the schematic?

https://www.diyaudio.com/forums/pass-labs/321925-diyaudio-watt-m2x-post6316096.html

4sets from the GB 1set (2 IPS6 and 2 IPS7)
1set 8,5 Euro
2 sets 12 Euro

Hi,

It's been a while since I visited the site, as I haven't been DIYing lately, but now I need some advice.

Just this weekend I finished recapping an old Marantz SR1000, it had a decent sound, although it was never a showstopper. It had always been a good receiver (I use it on my pc), until a lot of the caps in the power circuit decided to blow up simultaneously. I bought exact equivalents for all except the reservoir caps, which I bought 50% bigger. Also recapped the amplifying circuit, with same value caps all around. Basically replaced old Elnas with brand new ones. It was a bit messy due to all the cabling to the two boards, lack of room etc. But got it done and it all works fine ..........

except that the highs are now noticeably harsh. Which was not the case before, although it was never on the sweet side.

I'm hoping it's just a "burn-in" issue, and am trying to give it some hours playing.

So, I have two questions:

1.- Would recapping have this effect in the overall sound of the receiver ??

2.- Is there any way to fix this, make it sound less harsh and more refined and sweet, even precise for that matter. If I were to describe the sound in terms of images, it sounds as when you set a picture in extreme sharpness, it goes wrong and feels unnatural.

Thanks,

Manolo

I'm totally unfamiliar with solid state, and I'm troubleshooting a circuit that uses 2N1370 transistors. On one of them, the base and emitter sit at exactly the same voltage.

My cheapie component tester identifies it as a single diode, but that's in circuit.

Could this be a short between base and emitter? Or some other failure mode?

Hello,

noob question here, please be kind 🙂

I've bread boarded this simple EQ and it's working, but i only have 10k dual pots and the schematic asks for 50K. What calculations needs to be done to change the value to 10k?



source of the schematic:
superstars of the All electric kitchen

Thank you!

New member starting a my TU-8100 build. I do have a question concerning speakers. Everything I’ve read talks about high-efficiency speakers. Just curious as to any recommendations that have actually worked for those who built the kit.

Thanks for your time - look forward to your comments.

Does anyone know what 6.5"/170mm bass driver PMC uses in their OB1 speaker? It looks like it could be a Peerless 830946 or possibly a Morel HU631. PMC's web site says it is a doped 170mm driver with cast magnesium chassis. This would indicate to me that this is a paper coned woofer. Also, PMC seems to like using the Typhany Group's (Vifa, Peerless & Scan-Speak) drivers. Any suggestions? I have already selected the Scan-Speak R2904/7000 tweeter & ATC SM75-150S midrange and am now trying to pin down which woofer to use. Any ideas are more than welcome. I am using Martin King's transmission line tables to help out with the design. Has anyone used them before? They look like he really knows what he is doing.
Thanks to all,
John

I have played around with Equalizer APO for trying out a digital XO for my speakers. But now when my new speakers are getting closer to being finished I need a good audio source for them. With my old speakers with passive filters I use optical out to my amplifier which has a DAC that does the job. But that option wont do with active filters since I need two amplifiers. So I am looking into which solution is the best one, at a budget.

Shall I go for a MiniDSP 2x4 HD? Seems simple enough to set up, get some room correction and FIR-filters. But I've heard that sound quality can't match a good soundcard or good DAC. Over here that will set me back 300€, and close to 100€ more if I go with an UMIK-1.
The other and basically free alternative is to make filters in Equalizer APO, as I understand it you can do phase correction that way too. But for that I need a new sound card, which puts me almost in the same price range as the MiniDSP-solution anyway. And maybe a mic aswell.
Which will perform the best? Will it be alot easier to get things working with the MiniDSP? Is software + soundcard inferior? I won't use any other audio source than my computer so I wont be held back by a software solution in that aspect.

I am reluctant to settle for old fashioned passive filters since I want to play around and modify my speakers. And as I understand it digital filters will for the most part get me better results, at least with my level of knowledge in filter design.

The whole reason I'm into DIY to begin with is to keep costs low. So I wont just throw money at the problem until it gets right. I want to get as close to my goal as I possibly can at my first try. :/

I'm testing some line level center tapped transformers today for how evenly they phase split a signal. I've never done this before so maybe someone can explain what I'm seeing. I'm using this transformer:

EDCOR - XSM Series

10k to 10k

I hooked the function generator to the primary and set the level to 1 volt. I hooked two channels of the scope to the split secondary so the scope shows the split signal very cleanly in perfect antiphase. Leaving the level the same I try out different frequencies. 1K, 5K, 10K, 15K, 20K...

Here is my question. As I stay below 15K the amplitude of the two phases is pretty much equal within 1%. But as I move above 15K to 20K one of the phases grows in amplitude over the other phase by a greater percentage.

Is this caused by the fact that the transformer is reaching its rated frequency limit? Or is it caused by the fact that a higher frequency is exposing maybe that 1 turn difference between the secondary halves? Or is it caused by core behavior at the higher frequency?

In any case the antiphase remains perfect, its just that at higher frequencies one side of the secondary grows noticeably taller on the scope.

Using this as a PP phase splitter would cause an imbalance at higher frequencies? There is not much musical content above 15K. Am I being too picky? I was expecting to see both phases stay identical in amplitude as frequency increases.

The Edcor transformer above is actually much better than some others I tested today. But they all exhibit this rising frequency brings on amplitude imbalance behavior. In fact one cheap radio replacement transformer I have started to show this imbalance as I approached 8K to 10K! This one (its a stepper-upper so maybe that makes it even more difficult to keep balance).

https://www.tubesandmore.com/products/transformer-audio-interstage-10-ma

Do you suspect a step-down splitter would probably not exhibit this behavior as much? I have not gotten to testing a few of those yet. I suspect they will maintain balance better just on a hunch, if so I'd probably want to use the
at as a PP phase splitter instead, then get back the gain in the driver.

OK I just tested the Edcor 10K to 600R. It exhibits the same behavior but not as bad, I start to see it begin at 13K but the percentage difference between the phases in amplitude is not nearly as far off as a step up or a 1:1 transformer.

Hello friends.

After a long time without posting due to work and other problems I bring a new amplifier that is still being developed and tested.

The PS80 darlington series is a small amplifier with darlington transistors at the output for a very simple purpose: to push my bass.

Simulator tests (the circuit is not yet definitive) have shown excellent performance at high frequencies as well, but I will use it to push my bass speakers.

I will still manufacture the pcb, 'tune' the amplifier and after that do the test using a QA401 audio analyzer, from QuantAsylum to better see the behavior of THD, IMD and the like.

Here in Brazil as always very hot and with good music !!! Hugs
(Paulo from PHS Audio)


Follows the provisional and still pending adjustment of values

View attachment PS80-NOVO-OPEN.pdf