Hi all,

I'm going to preface my questions and potential stupidity by saying that I'm relatively new to Hi-Fi separates and therefore am fairly green in terms of technical issues. So apologies in advance and sincere thanks for any help.

I've recently picked up an NAD 3020e off eBay that's in lovely condition and was hoping to use it as a pre-amp for my Technics 1210 running into my Pioneer amp.

I'd (foolishly it seems) been under the impression that all 3020's had a separate pre-amp stage but it looks like I've got and bought the only one that removed that feature.

So my question is this: is there any way that I can use the 3020e as I intended without blowing the whole setup to hell?

It's been suggested that I could run the Tape Out from the NAD into the Line input of my Pioneer but I'm slightly concerned that the signal coming from the NAD won't have any of the warmth or tone that I bought it for. Would that be correct?

Any help would be greatly appreciated!!!

I'm wondering if anybody can advise me what tests I can do to determine whether a parcel of 500x 2SK170s I bought from a supposedly reputable source ... are genuine ... or fake.

Thanks,
Andy

So I have a new TKD 50k 2CP-2511 and I'm seeing very strange measurements on the meter. Starting from the fully counterclockwise position, it measure 42k. As I slowly turn it clockwise, the resistance increases to 60k, then starts to gradually decrease. When it gets back to 42k, it's about about the 1/2 mark, and the last 1/8" or so drops rapidly from about 13k to almost 0.

This seems defective. I see no taper profile on the TKD datasheet that looks anything like this. Also, I just replaced the batteries in the DMM, and the measurements are repeatable.... so I don't think I'm out to lunch.

Is there anything to do other than return this?

hello all, i have a friend in Texas and planning to go on vacation to the Philippines at earliest possible time.....if you have defective dynaco pas 3 or pat5 please let me know so i can direct him to you....thanks in advance....

All Sold:

Aurium Cantus AST2560 - Pair $225 - Sold
Aurum Cantus AST2560 Aero Striction Tweeter

Dayton Audio ES180TiA-8 - 4 total, 2 pairs - $200 Pair - Sold
Dayton Audio ES180TiA-8 7" Esoteric Series Woofer 8 Ohm

Epique E160CF-8 - Pair $300 - Sold
Epique E160CF-8 5-1/4" Damped Carbon Fiber Cone FEA Optimized Neodymium Speaker Driver 8 Ohm

Tested only and half have not even been opened. I spent the past year and a half building a three way speaker but life changes prevented me from finishing. Half of the speakers have been mounted and tested with very low wattage, the other half are new and unused.

Shipping is included from Kansas within CONSUS.

Please feel free to ask any questions and thanks for looking.

SOLD

Selling my recently built Tubelab SSE, because I suddenly have too many amps.

Pictures are here.

Wired in basic triode configuration.

Output tubes are JJ EL34. Output transformers are Toroidy TTG-EL34, Made in Poland, enclosed in powder coated black metal bells. Power transformer is Hammond 274BX. Also contains a triad choke, Auri-Caps capacitors, Rean input connectors, and high quality components used throughout the build.

I custom designed and cut the enclosure from cherry veneered MDF. Very handsome look. All press-fit joinery, with "living" radii on the corners, which also provide some interior ventilation. Since it is not a metal enclosure, all components are individually wired to ground, per the advice of George at Tubelab.com.

Works beautifully. Sound is very warm and pleasant; the quintessential tube sound. More than sufficient power to drive my Bozak B-401 Rhapsodies.

Asking $700 obo, plus shipping.

it would need a nearly ready made and cheap 10 liter back chamber

I am in the final leg with my SSE build. It has moved from breadboard to an enclosure I built, and now I have been focusing on refining the sound so that I can down tools, and say that I have finished.

The top is some sort of heavy duty baking tray I rescued from recycling, and I like the rounded lines that are repeated with the base and toroids.

The bass is excellent, but it is lacking some elelement of brightness. I had been using a bluetooth source with Youtube, but I tested today with a CD player and good quality recording, and there is no doubt that there is something lacking in the upper ranges. For instance, Funeral for a Friend, after the initial synthesizer refrain, the band plays and there is a high hat, which is there, but sounding a bit muffled and not part of the sound stage.

It is a bit frustrating not having all the test tools, or a reference system to compare with. My SPP amp is not here, otherwise I could compare with that, but I remember that that had the 'wow' factor, which the SSE is currently lacking.

I am using UL with CFB. I have tried swapping tubes around. Currently have new JJ EL34s, but before had some old Telefunken EL34s liberated from a guitar amp. The driver is a Telefunken ECC81, but I have also tried a CV4024 (which does make the bass more dominant). While tube swapping, I managed to pick up an ECC83 without noticing (reduced gain and poorer sound), but it goes to show how you have to be careful and be organised when swapping tubes. Could have been something with a different pin out.

I have a DPDT switch for speaker impedance between the OPTs (where hopefully it will not get used during running), and I am pleased with that solution. I will be adding a 300ohm 5W resistor from the line to ground for each speaker connection to protect against no speakers. I am thinking this should be as standard as adding a fuse to the power supply - are there any nay-sayers?

I am pleased with the layout. The signal wiring is short and down one side, the power down the other, and the outputs at the back. Only downside is the proximity of the tubes to one of the OPTs, but I may well mount them vertically to get round that. (There is a perforated base to be fitted).

As I am sure most hobbyists will agree, the hard part is keeping the momentum going after the breadboard is delivering the goods, so that there is something that is safe and presentable. I am hoping that I will be able to sell it eventually for the cost of the materials, since it is hard to counter the 'what do you need another one for?' questioning of my better half. At least I am fortunate that she is appreciative of the detailed sound, and she is a music fan.

So I've been playing with rephase and room correction with my DEQX for a long time and I wanted to share some of my recent results in the hopes it helps someone else. I have had mixed results in the past using room correction

attempting to take measurements from a single listening position or even from 3 ft from the speaker and then trying to EQ the room.



I've always felt like the results were marginal or even made the sound worse. Well what Ive learned is there can be a huge learning curve (Im still learning) after years of playing with this stuff. SO dont give up on it ! Anyhow the best rephase tutuorial Ive found was by someone who goes by 'bear' (ive attached the tutorial).



Anyways, I added something of my own that I just thought of that made a HUGE difference to the results.



Previously Ive always just taken a measurement from a single point for each speaker and then tried correcting the phase and FR from that point. But I think the flaw is of course when you move your head 1 inch or more from that spot the FR changes and you're back at square one.

So I finally tried taking measurements from 48" and 78" at 9 degree increments (0 to 45 degrees) for each speaker and then vector averaging the measurements in REW and then correcting the resulting phase using THAT measurement. Also I started the sweeps at the lowest frequency wavelength from the distance measured. ie the 48" measurement is 285hz, the 78" measurement was 175hz. What a difference. I highly suggest trying this and creating fir filters this way if you havent already.



I think it does a way better job of averaging out the FR and phase in the room and the reflection come back more in phase which opens up the sound stage. Being that every room is different I dont think it would be possible for speakers to be perfect for your room out of the factory and Im not aware of any ARC that corrects using this method automatically.



I had almost given up on room correction until I tried this and its made enough of an improvement that Im going to continue attempting to fine tune it. Let me know if you have any questions and Ill try and answer.

Hello all

I am almost finished a build of Microtower Castles using FR Alpair 7as (they sat for a couple of years on the shelf!) and am already looking to commence my next project.

Looking for a 3 way this time, with a bass driver of between 8-10”

I am familiar with the website from Troels, are there any other options available?

Note, I am looking to build not design, at least not yet!

Tks

I know this is a pretty old story. Many of us are seeking for these for years. 😉

Is there any chance to make a batch of these? 😕

Sorry - please remove posted in wrong forum. Thanks

Hi All,

I seem to recall reading somewhere that TDA2050 gave a more refined sound than LM3875 in gainclone implementations. Any views on this?

Also, I have 2x300 VA transforners (20V secondary) which I intend using for my LM3875 implementation. Is it corect to say that teh higher the VA rating of the transformer the better? I have seen that others are typically using only 120-225 VA transformers.

Ryan

Up for sale direct drive Victor TT-81 turntable motor deck.
Excellent working condition. Asking $400US .This is Japanese version with 100V power voltage. 120V step up transformer will be included.
VICTOR TT-81‚ÌŽd—l ƒrƒNƒ^[

I need a decent ESR tester for testing large PSU electrolytic capacitors - typically 15,000uF to 22,000uf in the 80V-120V range. I understand one such unit is the PEAK Atlas ESR+ model ESR70.

Are there any others that I should be looking at?

Stay safe.
Rgds
Mayank

Hello gentlemen. I would like some input on an ob system. my budget is around
$500 for drivers and crossover parts. would like a mtm design suggestions. $$ is flexible. I would also like to know if anyone has used the 10 inch dipole from

speaker addict?

ok lets hear it

Hey all, I'd like to build my own crossover with the same point / slope as this one:

EV Crossover - Album on Imgur

I believe the crossover point here is 1,700hz....but not sure on the slope.

Any help is appreciated!

-Jim

I normally set Show Threads to 100, the max. Lately the button has been usually just flipping straight back to 20. If it holds a while, you still cannot select better than 20 threads.

??
Using both Chrome and Microsoft Edge (latest)

Overview from world's best historical and currently available electr./audio Magazines

This could be an interresting collection of all magazines, not only english, French, German and Japan editions - we have more than 200 countries:
http://thumbs.dreamstime.com/thumb_367/1235114020ss78pr.jpg

I will start with a very small amount of editions and hope of much more, especially from the east European countries, but also far east countries, Brazil and the spain language countries (in the meantime relativ small losses by translate about "Fine-Reader/Google"):

Please note: no clean comparable test magazine for HiFi/audio like stereophile or the new "l' audiophile" here included - about this magazine listings go to
Audio Magazines


1) Electronics World
Electronics World - Electronics World
File:Electronics World Sep 1959.jpg - Wikipedia, the free encyclopedia
http://www.marklev.com/JC3/JC3-from-Electronics-World.jpg
Amplifier Articles in Electronics World & Elektor

2) Ремонт электронной техники (Repair of electronic components, Russian language - in this country all devices will be repair, even cheapest stuff like cell phones, dish receivers, cheap MP3 players and all the other electronic stuff)
http://www.radio-portal.ru/book/%C6...%ED%EE%E9%20%F2%E5%F5%ED%E8%EA%E8/2000_06.pdf
Æóðíàëû "Ðåìîíò ýëåêòðîííîé òåõíèêè"
http://www.shema.ru/0_s/mwo/SANYO/EMG_430.pdf
http://www.all-library.ru/zhurnaly/texnicheskie/1753-remont-i-servis-11-2009.html

3) 'l Audiophile (French)
http://6bm8.lab.free.fr/Documentations/Revues/Audiophile/index-1977-1988.html (index-1977-1988)
https://web.archive.org/web/20090218161354/http://www.audiophile.lu/index_fr.php
currently other magazine than from old days. Old magazines available on CD:
https://web.archive.org/web/20100518094713/http://nicolas.davidenko.perso.sfr.fr/revue/revues2.htm
https://web.archive.org/web/20100130100553/http://nicolas.davidenko.perso.sfr.fr/index.html
https://web.archive.org/web/2023120...LY/pXnJajbGgI4/s400/audiophile-couv-light.jpg
https://web.archive.org/web/20090205150033/http://www.audiotechno.fr/html/realisations.htm

4) "無線と実験" (MJ magazine, Japan)
all informations there:
http://www.diyaudio.com/forums/soli...sen-jikken-yearly-index-1924-2009-wanted.html

5) Elektor/Elektuur (German, Englisch, Dutch)
ELEKTOR.nl | Elektronica: Embedded Microcontrollers Audio Digitaal Analoog Testen Meten
http://miketimmer.nl/wp-content/uploads/Elektuur.jpg
Elektor Artikelsuche
paX: Audioverstärker mit Fehlerkorrektur - ELEKTOR.de | Elektronik: Analog Digital Embedded Mikrocontroller Audio Messtechnik
paX power amplifier
http://www.diyaudio.com/forums/solid-state/165165-edwin-20-watt-elektor-1970-may.html

6) ELRAD (German, no longer available, no successor magazine)
http://shackman-electrostatic-loudspeakers.reromanus.net/elrad-titel.JPG
Elrad (magazine) - Wikipedia, the free encyclopedia
HMG - Presse-Informationen - Heise Zeitschriften Verlag - 20.12.2005
heise online - ELRAD auf DVD
Shackman DIY Electrostatic ESL/ELS Loudspeakers and tweeters. Tube/valve amplifiers Röhrenverstärker. Elektrostatische Lautsprecher Elektrostaten-Selbstbau Audio engineering Literature

7) "Chip" and "populäre Elektronik" (German, no longer available, no successor magazine)
http://www.gw-home.de/images/elektronik.jpg
http://resources.emartin.net/blog/pic/Populaere-Elektronik-1982-10-sm.jpg
Populäre Elektronik ? Wikipedia
1978-1983 Vogel-Verlag (emartinnet)

8) TAA ("The Audio Amateur") and "Speaker Builder"
http://www.arcdb.ws/ST70C3/AudioAmateur_4_1977.jpg
http://www.carveraudio.com/sb[1].jpg
http://www.alkeng.com/bruce2.jpg
AUDIO AMATEUR BACK ISSUES
http://www.passdiy.com/pdf/citation.pdf
A75 Part 1
https://www.wilmslow-audio.co.uk/catalog/index.php?cPath=39
Ribbon Tech
The Maverick 2's

9) Funkschau (German, in the early days similar to Japan's MJ magazine)
http://www.guenthoer.de/doku/funkschau-2284titel.jpg
http://www.suertenich.com/html/radios/Concert_Boy_Funkschau.jpg
http://www.suertenich.com/html/radios/grundig_58.html
http://www.addx.de/textarchiv/archiv-funkschau.php
http://de.wikipedia.org/wiki/Funkschau
http://www.radiomuseum.org/forum/funkschau_1944_jahresuebersicht.html
http://www.jogis-roehrenbude.de/Russian/Funkschau-Ru-Roe.pdf
http://www.earlytelevision.org/images/FunkschauNov1936_1.jpg
http://www.earlytelevision.org/images/

Trusted place to source new KSS-150A lasers

Hi

I just got a nice NEC CD-620 today, TDA1541 based player, stock is a bit more open than a stock CD50


Anyway, my good friend advised against a local supplier here, as most of their lasers are dead or arrive dead.

Any trusted ebay sources or others please share

Many Thanks
Regards
Sam

In an equipment rack that's totally exposed on all 4 sides (Quadraspire Q4, see link below), is having 2" of free space above a Firstwatt clone adequate? The amp would go on the bottom shelf

Q4 Evo – Quadraspire

I bet this has been asked before but here goes. Where would a fellow find a matched quad of 7355s? I know if available they will cost some money but likely a lot less than the mod's needed to use something else in a H-K TA5000, which has a very finicky fixed screen/cathode biasing scheme.

One pair for stereo amp completed boards for sale with original Onsemi transistors. Ad your own input capacitor and Psu and you have verry good sounding amplifier. Build with good parts. Price is 50 euro for bouth boards and caa. 14, 90euro shipping inside EU.Payment with paypal with option for friends and family.

For sale Nos matched pair of verry good sounding tubes buyed by Tubesandmore from Netherlands. 6n23p typ with rocket logo from 1977 and silver shild, single wire!! I pay about two years back 75 euro for a piece so 150 for pair plus shipping. I dont have original boxes anymore, I cant find this, but I will pack the tubes verry well. I buy this tubes for my tjoeb cd player but on the end I have use in there Siemens e288cc, so this tubes have around maybe 10 working hours and not more. So condition is like new. I would sell this for 100 eu plus shipping inside eu or best offer. This are one of the best sounding tubes and you can use this in place for ecc88, e88cc, 6dj8.......!Shipping inside EU 7,90 euro.

Anyone else had any issues with Arrow?

I was having quite good luck with them for a while but...

I ordered 16 caps on June 7th. They figured they would ship on the 11th and I'd have them by the 15th.

They still haven't shipped them.

Four times I've contacted support through chat. Four times I got the same "I'll make sure the warehouse expedites your order"

The last time I asked to cancel it since it hadn't shipped. The chat person said they couldn't do that.

I then tried to call them on the phone. The first time the automated system said it couldn't take my call and to call later.

The second time I got to hold for someone for someone for 25 minutes only to have it ring through to a silent line which I hung up on 5 minutes later after saying "Hello? Is someone there?" a few times.

I've now opened a dispute with Paypal. Let's see if that get's there attention.

Anyone else have any stories to share about bad purchase experiences? I've never had this much of a hassle with any other place. That includes sellers on eBay and Aliexpress.

Koda

Hi,
I have only experience with Class A Amps (Pass XA25, Aleph J, Bba-3…) to drive my Magnepan 1.7i.
Best match is the XA25.

In summer time, the heat development is heavy in my listening room.
I am interested to build a high class ab amp and hope I will get some input here.
First candidates I found:
- Pass AB100
- SymAsym

Any comment or tips?

Thanks 😉

Daniel

Years ago, I bought a huge lot of used Hypex modules. When I bought it I was told that most are working but there might be some that are not working. I have randomly picked some psu and amp modules from the lot in my own projects during the years and only found one bad amp module and one bad psu module. Here is what I have left. I haven't tested them and don't have the energy or time to test them so for that reason I'm selling them as unknown condition.

2pcs SMPS1200A180 V7. These are missing the heatsink, otherwise no visible defects

1pc SMPS1200A700 V3. No visible defects

2pcs SMPS400A180 V9. No visible defects, except the plastic covering over the electrolytics is worn

10pcs UcD180LP OEM V8. No visible defects

I preferably sell all of them as a lot, how about 150€ for the lot + shipping. Or make me an offer of what you want. Can be shipped anywhere, just ask for shipping quote.

Detailed photos can be found in below link:
Hypex - Google Drive

I'm in the process of designing a modest two-way speaker. Up until now I've only made XO's by using the verdor-provided FRD and ZMA files (or I traced graphs if needed). This time I want to measure the drivers first ("gated"), and design the XO based on my own measurements. I've been reading up on how to do this from various sources, like posts on this forum and the REW help file. I have two questions left at this point.

1. Should measurements for both drivers be performed with the mic on the v-axis of the tweeter, or on the vertical axis' of each individual driver?
2. Can I just use the vendor-provided ZMA file? I have a measurement mic but no DATS or similar.

I have two Sure amplifiers that have problems.

AA-AB013V120: This one has never done it. I have used different power supplies. The Hmute light is on indicating there is a problem.

AA-AB32971: This one I bought recently. It sounded very good with this power supply Gratis Verzending 240 w 24 v 10a Enkele Output schakelende suppy in Gratis Verzending 240 w 24 v 10a Enkele Output schakelende suppy van Stroomvoorziening op AliExpress.com | Alibaba Groep

Unfortunately one of the channels suddenly failed and a red light on the board is indicating an error occured.

In both cases the manual gives no information what to do. Any suggestions from this forum?

Hello there,
I am currently working in China and I am thinking to visit the factory producing this amp US line 6P6P 10W + 10W super linear push pull tube amplifier, CLC filter, S / N up to 108db|Transformers| - AliExpress
It seems they are taking care of finding right components, but I am not an engineer so my knowledge is always limited, does people here have an opinion on this ?




They also have one similar with a closed box design.
I find it interesting these small chinese companies making vintage circuitry design come alive.

Attached is a schematic and simulation results for a simple cascoded "Fetwhite" buffer. The simulation results were surprisingly good, so I did a hack job on one of my buffer modules to try it out in my test preamp. Audible results are excellent. The unit gain buffer is also a good gain match for my overall system.
I will need to wait until I'm back at work next year before I can really do any serious testing on the new circuit, as all the good gear is there. It will be interesting to see if the test results for THD are anywhere near as good as the simulation.

I plan to try out some simulations to check the difference between using a simple cascoded buffer and the White circuit. Last time I loooked, the White circuit had lower distortion, but the simple buffer would allow me to try a cascoded bipolar current sink instead of the JFET current sink current used here.

I have the opportunity to purchase a Yamaha A1 integrated amp at a low price and am happy to service it myself.
I intend to use only it’s pre section teamed up with a my recapped Yamaha P2200.

Please could anyone comment on the quality of the A1’s pre amp?
I hear that the phono section is very very good, and I only need a couple of inputs.

Would the audio quality be as good as a Yamaha C4, or the pre in a CA1000, CR-1020 ?

So.....

i have this autoformer from Dave Slagle, the ELMA stereo version

Gonna use this as a volume control in an enclosure with 1 out, 3 inputs
maybe later add an XLR balanced line in/out

-i want to use a selector or toggle switch
the selector needs to be 2 pole,4 pole? where can i find a 3 way toggle switch?

-does anybody have a wiring diagram, i know this shouldn't be difficult but this design is quite new for me 🙂 so just wana make sure!

Cheers all! Filip

Hello!

I am currently building a Bluetooth portable speaker. Everything about the build was okay but there is one thing bothers me a lot, the Bluetooth receiver generates noise no matter what power source I connected it to.
The hum is in high frequency and the frequency goes up and down. Somehow the noise is a bit better when I turn the volume knob(b100k) all the way up, and somehow, the hum will eventually gone after powering up the speaker a while, leaving an acceptable white noise at the background like an old FM receiver. The noise also decreases a bit when it is streaming songs through Bluetooth, when the music stops, few seconds later the Bluetooth receiver sort of switch to idle mode(? and the high frequency noise is back again.

I did tons of searching on the internet to find the solution, and everyone solved the problem by using a dc-dc isolator, I did the same and it didn't work for me.

Because I can't do anything with it, I had to ask here. At this point, I wish I know the circuit design of those speakers from big companies. How JBL managed to get a very clean sound out of a Bluetooth module??

Anyway, here is the my circuit diagram.


sorry for the bad schematic, I am still new to this area.

I know this is diyaudio but i hoping i can get some help with a buying advice.

My company has a big meeting room (hard floors, office type of ceiling tiles, lots of glass windows (top to bottom) and about half with interior walls.

In one end we have a projector with a decent size screen where we hold company meetings (with zoom for remote employees). we use round 6" speakers (four) flush mounted in the ceiling tile for sound, both amplifying the voice of the speakers as well as to hear people on zoom.

The sound is absolutely dreadful. We often do happy hour after company events and i put on playlists from spotify but its terrible.

I'd like to get a decent set of speakers (on floor or in ceiling) that can be used for both voice (PA) and music for happy hour. It does not need to be super loud (We're not dancing) but decently volume is needed.

Any idea what to buy? I was tempted to rush over to best buy and get some klipsch monkey coffins for a few hundred bucks but decided i should first check with you all for ideas?

I have the amp, a regular onkyo amp that seems decent and i'm donating my personal hometheather powered subwoofer to them (i've upgraded).

So any ideas on speakers you think are good for this usage? I can go up to lets say $1,000 or $1,500 but we are scrappy -cheaper is better...

thanks a bunch!

This amp is sort of similar to the GTS300

This amp is drawing .5A with just + and - connected. When I attach REM, the amp powers up and idles at 2A. Channels 1&2 work, but channels 3&4 do not.

In troubleshooting the PS side, I pulled the PS driver board which also removes the TL494 from the amp. Still drawing .5A.

Anyone familiar with these?

I have some speaker divers for sale
Dynaudio midbasses 2 pc (in guess they came in volvo doors and are 8") working good condition
Focal 6,5" k2 midbass drivers 2 pc not good contition
Fountek FR59EXE 2pc tried in car use
Dayton audio RST28 tried my home speakerd good contition 2pc
Seas 27tbfc/g good condition 2pc
Seas h 87 one does not work 2pc

All drives 125 euros + shipping.

Google Drive: Sign-in

Google Drive: Sign-in

Google Drive: Sign-in

Google Drive: Sign-in

Google Drive: Sign-in

Hi,

Thinking of building Yves 6L6 PP amp. Is here anyone who built it and is using it?

Thanks,

As title says, i have burned the resistors and Transistors on the Power side. I've ordered the replacement transistors and am stuck on the resistors. Can someone help me with ordering the correct resistors? The ones on the amp are burned up and am not able to read the color value. Any suggestions?

Is there a preference for power capacitors in a rockford amp? I am replaceing the caps in a 301x and would like to narrow down my options.

I am opening a thread for the UJ3N065080K3S SiC JFET. Is there an operation area that has triode-like behavior?

This is a thread for curve tracer geeks.

I have attached the results of a curve tracer session of mine on this JFET.

In my experience, devices that have triode-like behavior, this behavior is at high-ish voltage and low-ish current. These same devices have pentode-ish behavior at high-ish current and low-ish voltage. I will post that behavior in the next post.

I found a source for PC solder pins that work with Novar tubes so I designed a circuit board for a Novar damper diode power supply. It can be used in a hybrid bridge configuration or with a center-tapped xfmr by just leaving out the diodes. Also, the heaters can be powered by a separate or common supply by installing a couple of jumpers.

These are not for sale, but to get an idea of the cost, the boards were $2.00 each including shipping. The pins are $0.66 each. I only populated the active pins, 5 pins per tube. The PC terminal blocks are about $8.00. So the cost comes out to about $17.00 for the whole thing.

This may be overkill but I think it's a neat idea. Makes the terminations easy.

Scott

Just curious how the shortage has impacted you, your business and what measure have you taken to overcome this?

Just from my end I have bought as much as I can at sometimes three to five times what I normally pay to create a stockpile. And I am more selective of the amps we repair, especially older models which can be parts hogs!

I am working on a pair on L08m Kenwood Mono blocks- one works fine, the other has a NFB (RL1) relay that keeps clicking. The rate of clicking is associated with the offset adjustment.

The problem is I do not have 24v on the coil, and when I trace this back it comes from one side of R112 in the attached diagram. The other side or R112 is attached to the Collector of Q47, which in the bad amp is 0v, whereas it is 64v on the good amp. So I surmise it is not being turned on. Q46 and Q47 drive this relay.

As I trace this back-Q39 on the good amp has 8v on the collector, where as the bad amp has about 3v (fluctuating).

I have repalced all the caps, tested out of circuit all the transistors and tested in circuit all the diodes-and replaced a couple-all the resistors have been tested in or out of circuit depending on their measurement, again all test good.

I have checked (and checked again) all cap values and polarities, but I am at a loss to understand why the circuit is misbehaving. The voltage at the junction of C29 and D33 is 12v on both good and bad, and the B+ measures at 65v at the emitter of Q46 and Q45, and both there bases are at 64v (or so).

On the good one the collector of Q46 is 65v (as is the emitter of Q47), where as it is 55v on the bad one.

So I think something is not being turned on

I have attached the overall circuit, page on the relay operation and circuit oif that section with voltages. The additional complication is Q40 and Q41 which are not shown on the circuit and are mounted on the PCB and listed in the parts list.

I will try and trace out where they connect. Q40 shares a common collector with Q39, other than that their voltages are the same on the good and bad units

any thoughts as to where I should be looking?

For Sale: Peerless by Tymphany NE265W-04 10" Paper Cone NE Woofer 4 Ohm

$100.00 Shipped CONSUS - USPS Tracked

I purchased this driver from another member in 2019 thinking I would use it in a three way build but went another direction. I did recently put it in a 1 cubic/ft sealed enclosure for testing and it worked flawlessly.

Peerless by Tymphany NE265W-04 10" Paper Cone NE Woofer 4 Ohm

Will be shipped in original box. Thanks for looking.

For sale are a mixed bag of Capacitors, Inductors, and Resistors.

$60.00 Shipped CONSUS - USPS Priority Tracking

I am selling all together for way below what it would cost to purchase individually.

Never soldered only tested. Let me know if you have any questions and thanks for looking!

Inductors
Jantzen Copper Foil 1.20mH 14 AWG
Jantzen Air Core 2.5mH 18AWG
Jantzen Air Core 2.2mH 18AWG
Jantzen Air Core 0.8mH 20 AWG
Jantzen Air Core 0.55mH 20 AWG
.10mH 20AWG

Capacitors
Jantzen Audio Silver Z-cap 3.3uF
Jantzen Audio Superior Z-cap 3.3uF
Janzen Standard Z-Cap 6.8uF
Jantzen Cross Cap 12.00uF
Solen 11uF
Dayton MPT 90uF
Dayton MPT 4.7uF
Dayton MPT 2.7uF

Resistors
Mills 8 ohm
Mills 16 ohm
Mills 6 ohm
Jantzen 4 ohm
Jantzen 2ohm
Jantzen 2ohm
Jantzen 22 ohm

I have a vexing issue with DSD and was wondering if there was a simple, obvious solution I was missing.
I'm playing native DSD recordings from my Dell laptop with Core i7 processor to my Buffalo IIISE DAC through a Sonore Audiobyte USB to I2S board and get great sound with PCM at all rates, and with DSD64 and DSD128. When I get to DSD256, though, playback has a low-level crackling sound mixed in with the playback. I hear the crackling whether I play the files using Foobar (with a multitude of different settings) or HQ player (trying every filter and modulator setting on HQplayer).
I have the Buffalo IIR filter set at the default (recommended for PCM). I'm thinking if this was an issue with the Buffalo's IIR filter, for example, it would also happen with the DSD64 and DSD128, right? Or could the higher sample rate of DSD265 cause issues with the DAC that don't appear at the lower rates? The dip switches are not very accessible in my DAC so I'd like to known if I'm barking up the wrong tree before I tear into the unit.

Any help is greatly appreciated!

I had a question regarding if this box

BLACK 6.5" DUAL 32-Hz PORTED SUB BOX

would be appropriate for this particular woofer. I've done some reading but just got more confused as i read more.

Dear All,

Anybody who ever measured a loudspeaker driver using MLS or ESS measurement systems faced a problem with placement of FFT window. In order to obtain true minimum-phase phase response, the FFT window must be located where it should be.

I have produced two papers describing the method of dealing with this issue.
In the first paper, I introduce Inverse Hilbert-Bode Transform and it’s application.

https://www.bodziosoftware.com.au/IHBT_White_Paper.pdf

The second paper describes an automated method for extracting minimum-phase phase response and more.

https://www.bodziosoftware.com.au/Automated_IHBT.pdf

If you have any questions, please contact me on
bohdan@bodziosoftware.com.au


Best Regards,
Bohdan

Hi,


This is possibly similar to LM3886 - getting hot - low volume


I've soldered up my LM3886 board and getting a hot chip (using a bad heatsink, if I use pliers to press it against a big heatsink then doesnt get hot).


The main issue I have is that it's apparently outputting 0v at the output with no load connected, and PC line output connected as input with no input attenuation via a volume potentiometer.


I had previously built a veroboard version (minus the zener mute function, minus the thiele and zobel networks) and that used the same bad heatsink and worked and had no heat issues.


This is a different chip - when I get time, I will swap the chips to see if I have a faulty one.


I'm using a pcb this time for the new amp, components are more compact compared to veroboard.


Rgb1 on the schematic is just a bit of hookup wire that has not been soldered - intent to use 1ohm 1w resistor. This might be causing issues, although continuity seems fine on those points, it might be introducing noise.


Anyone able to point me to the right direction please?

1 Arduino board with Buffalo Shield and 3 Display circuit boards.

I've never used these and I believe they were attached to a Arduino controller for a Twisted Pear DAC layout. I picked them up as used parts with other Twisted Pear items (see other offers here).

Display 1: YM2004A and has a small daughter card on it (I2C LCD extra...)
Display 2: 2004A V1.2 U3 also with small daughter card (TWILCD)
Display 3: NewHaven NHD-0420dzw-aq5 with large daughter card (CE-Designs CE644 V1.3) and some cabling

Arduino board model UNO r3 with Buffalo Shield V1.0 and Apple remote.

I don't have a way to test these, if not functional we will work out a refund but I believe the Newhaven and the Arduino were still fully functional when pulled.

$85 includes shipping to contiguous USA Only.

Payment via Paypal friends/family required before shipping.

Twisted Pear:
Legato analog board
LCBPS power supply
Sidecar
2x master clock cards for the 9018 board
2x pinned to i2s adapters
volume board with knob and LED's.
And for fun Texas Instruments +/- 15v regulator boards (NON twisted pear).

$100 includes shipping to contiguous USA Only.

Payment via Paypal friends/family required before shipping.

Hi, I originally posted this in another forum, but felt members here may benefit from this also, so I am re-posting some key elements in the processes I used.

I just rewired my RB300 tonearm, with Isokinetik silver plated wire (Cardas cartridge clips with Mundorf supreme silver lead free solder) : straight loom to the phono preamp..., and finished making a custom 3kg disc to mount the motor from the Rega Planar 3 on. I also dampened the tonearm with 7 expandable earplugs, and put 2 very thin slithers of earplug foam inbetween the spring coils in the weight adjustment part of the tonearm (they ring like a bell), while it was set at 3.5g (maximum-opens the spring up totally) and then set the weight via jewellers scales - leaving the setting at 3.5g.

I have NEVER heard a Rega sound soooooooooOOOOOOO GOOOOOD...!!!

Extra wide soundstage, depth, transparancy, black-silent background, detail, with a laid back clarity...yet so much PUNCH and tight bass....

...and its still in the initial hours of being 'burnt-in'....I cant tear myself away from it.....I also have a ruby bearing in it, and acrylic platter. In the lead base, which I made from a jar stainless lid, I drilled a hole, got a paper-mate biro pen, and took the spring out, cut it in half, and put it in the hole, and used the steel bearing I replaced with the ruby one, for the platter, and used it for a 'thrust bearing' as part of the lead base.....

...man, what a rewarding effort...., some tracks evoked pure emotion....WoW

... I still need to finalise a few minor points...ie: ext-cable clamp, 3 point mini-feet on base etc...,

... that is an 'ancient' Shure M75EJ Type II on there with a near-new Swiss Huco Hyper-elliptical .2 x .7 stylus...The Nagoaka MP-200 is looking like a good cartridge/stylus....for future consideration hmmm

Just repaired Tannoy TS10sub.
Green light was on but no output.
Got schematics from here.
I dont have a scope so i
used a cell phone frequency app generator to line in L/R.
Traced with input to mini speaker which i saw on Billm Audio.
(Youtube)
Signal got to audio amp board then died.
I checked many components all ok.
Caps had no signs of releasing smoke buy i ended up recapping
5 electrolytic and 3 BP caps anyway. I figure one of the BP's in line were dead.
Tested all caps off board which showed all out of spec readings.
RT1 was suspicious reading 121ohm but I left in and thought I could
jump to test if recap didn't work.
Works fine now.
As EEV Blog David Jones (Youtube) would say.
Winner winner chicken diner!

Hi everyone,

I am working on a Roland AC90 Guitar Amp that is playing ok on very low volume but when volume is increased slightly it starts to clip on and off constantly. Like turning volume up and down very fast. I tried to attached a video of its performance but says file invalid. I’ll try and get a different method.

I disconnected the main drivers and tested all the outputs individually through another system Mono out, phones out and left and right out and all work absolutely fine, which makes me think the problem is on the AC90 Amp board. I had a look at the components on the board and all seems ok visually.


Would anyone have come across this fault before with this amp?

Any thoughts much appreciated.

Regards

Paul

Based on the definition, class B amplifier should have 0 bias current. However, I have not seen any hifi amplifier with a pure class B design (with 0mA bias), even labeled with Class B. They all have some bias presented, such as 10mA.


Couple Question.
1. Is amp with 0 bias output stage possible? It is efficient, runs cool. Why nobody use it.
2. It seems to boil down to the distortion. We have solved the switching noise of class D, why nobody solve the switching noise of class B? Maybe somebody did, I just don't know.

I recently bought a Digidesign Mix system consisting of several DSP PCI cards and an 8in/8out interface called "888" . The system uses a PC/MAC for running Pro Tools TDM. The problem was that the interface is a bit outdated and the sound is not extremely pleasing. The sample rate and bit depth reaches 48KHz/24bit maximum. Taking into account that the newer Pro Tools HD system is really expensive, I bought the older MIX system with the perspective of modding the interface to unveil the hidden capabilities.

Before starting the mods, I searched the internet for relevant info and didn't find anything. After months of experimenting I found the best combination of opamps and caps regarding my personal taste: Quick opamps with robust lows and detailed highs.
Here is what I did:

-Replaced all AD711 with LME49710
-Replaced all LF353 with LME49720
-Replaced all N5542 with LM6372
-Replaced L7805 with L78S05 and replaced the heatsink as well
-Replaced all SSM parts with equivalent THAT.
-Replaced the switching PSU with a bigger one of greater ampere value (+15V, -15V, +5V) because the new opamps draw A LOT more current.
-Applied decoupling ceramic COG caps 10nF/50V to all opamps
-Replaced all SMT electrolytics (most of them are 10uF/50V) with Panasonic FK (smaller size and far better specs).
-Replaced the 220uf/35V caps around the L7805 regulator with Panasonic FM 1500uf/35V

The sound changed DRAMATICALLY. And after adding/replacing the caps, I had no thermal issues.

Hi,

For my last blog article, I compared the performance of:

• Texas Instruments LME49720
• Texas Instruments OPA2134
• Texas Instruments LM4562
• Texas Instruments LM833
• New Japan Radio NJM2742
• Analog Devices LT1352
• Texas Instruments NE5532
• New Japan Radio NJM2732
• Analog Device LT1169
  

See here:
Objective Guide to Op-Amp Rolling - Part 1

Regards;
Leo

Hi

Has anyone used OFX.com for transferring money?

Is it secure?

Purchase guarantees?


Thanks
Andy

Hello

I was thinking of assembling my next xover on a single side copper plated PCB like this one. So everything connected to the ground is soldered through a little hole to the copper plated part, the remaining connections wired p2p on the other side, and the components affixed with cable binders/hot glue.

What would be the advantages or downsides? Has anyone experiences. I was also considering to get oriented grain steel foils, which would then be used to wall the inductors, and that would also be connected to the ground plane.

Hi guys ... Please see the attached image.
This is a Winisd simulation of a ported sub.
Black - without room Gain
Red - with room Gain starting from 28hz

Now the question is ...
1. Is the increase in SPL due to room Gain looks realistic ??
I mean how close is the Winisd estimation to the real world.

2. Room Gain works differently for sealed and ported subs ??

Allo Katana DAC currently configured for two power supply operation and FULLY functional, $275 including shipping in the US.



In case you may not know, the Katana is not currently available in the US or elsewhere, in fact - it is not even available from Allo. So, here's your chance at this great sounding DAC!

I love reading patents. Most of what I learned about the Danley products was from reading their patents. Today I noticed that John Sheerin, a longtime forum member, has snuck horns into Apple's new loudspeaker:

Patent US20170280231 - Loudspeaker with reduced audio coloration caused by reflections from a surface - Google Patents

Hi I would like to adjust the onix amplifier quiescent current to 65 which now measures 22mv across one of the 0.22ohm emitter resistors, I am convinced that this value is high

Sub amp is Dayton Audio SA1000, 950W @ 4 ohm, 1/3rd duty cycle, class AB, Carver down-tracking PS, ca. 29#, in production since ca. 1995 with only minor series change: added HP main speaker filter, subsonic filter, switchable 20 Hz EQ, rest of the amp unchanged.

Two SA1000 power a 4 sub array, two subs per L/R side. SA1000 are in Dr. David Griesinger's phase quadrature tuning, the L and R sides separated by 90 degrees to further maximize the array's natural mode damping.

The two front subs also serve as main speaker stands; each side wall has a sub.

To minimize SA1000 output cable length I sited each SA1000 vertically only an inch from a cabinet housing a reverberant field accessory speaker driver, an Eminence coincident 10" with compression driver (separate xo.) Imaginary V-lines from the sweet spot pass through the center of the Eminence 10" directly behind the sub/stand/main speaker.

The SA1000's horizontal face plate and the baffle (22 degrees from horizontal) housing the Eminence 10" are both 16" above the floor.

Overall performance improved a lot, including the bass, vs. my prior SA1000 siting with longer output cables.

How would you define perceived risk (if any) Re. SA1000 proximity to main speakers or 10" sub drivers? The Q presumes no speaker driver, esp. the 10" sub, is on 90 degree axis with SA1000.

This is a fully working set of Hypex modules. I used these to drive my LX521 speakers. This set makes 8x400W amplifier. All modules are directly from use.

The lot includes following modules:

4pcs SMPS400A400 V14
8pcs UcD400OEM V6
Some wiring + connectors, if needed
Aluminium parts and any other parts in the photos are not included

How about 300€ for the whole lot or make me an offer of quantities that you need.

Photos here: Hypex2 - Google Drive

Lets not bring device-to-device ground loops into the picture, for now just assuming the amp byself with the following components on seperate boards, each with it's own ground.

Power Supply
Low current input stage
High Current output Stage
RCA input
Speaker output


So we have 5 grounds here, staring all 5 of these components to a common point results in 120 hz hum.

What arrangement of star grounding(s) would result in the least amount of hum? I have been playing around with different combinations for about a hour and a half now and I can't eliminate the hum.

Hello,

I am looking to purchase a RTX6001 analyzer within EU.
Can be paid via bank transfer or Paypal.

Thank you!

Hey guys!

I'm trying on building some nice simple ultra low noise amp with noise values below the 1 nV/rtHz level. Read many papers and threads about that topic and built up several little amps with low noise JFET's like 2SK170, 2SK369 and IF3601. I use them in source mode going into a non-inverting Opamp LT1028 as second stage. My noise values and bandwith are good.. reached like 0,3 nV/rtHz and bandwith up to 1 MHz. So that's good, but what's not so good is the THD ! Often I got like 3-6 harmonics resulting in THD's of 0,5 to 3% so that's way too high for my application. I need some value below 0,1%.
Biassettings of the 2SK170 for example are like Uds = 8V , Ugs = -0,12V and Id = 6 mA. So those values should work out for good linearity in the input and output curves. But they don't :-( Mostly I get strong second harmonic.
I put up my basic schematic and a picture of those bad harmonics I get, hoping that anyone knows how to effectively reduce that THD!! Or is it not possible in a source-circuit to drop the THD below 0,1% ? Do I need some complementary stage or feedback to get better?

Supply voltage is +-12V not 5V and signalsource is like 10kHz with 10mVpeak.

Thanks for your answers,

Greetings
Tobi

Hi all.

I have build quite a bit with BJTs and opamps over the time, but I feel it's time to play with JFets, now that I'm in the planning phase of a preamp.
I struggle to understand noise figure on JFETs. My local supplier have the following:
2N5459: Noise figure: 3,0dB af 1KHz; Rg = 1mohm
BF245A: Noise figure: 1,5dB at 100 MHz; RG =1kohm
2SK246: No noise figure in datasheet
2SK117: Noise figure: 1dB at 1khz; Rg = 1 kohm

The 2N5459 is quite cheep, while the 2SK117 is expensive, so what is enough? I'll need normal line-in and a RIAA for MM.

want to sell some C3G tubes - SIEMENS. They are new - NOS and NIB in original packages.
Price 55€/pcs + shipping. I have 16 pcs.

I want to build 2 x 8 inch subwoofers for my hi fi system.
Any suggestions for drivers, prefer sealed but could use passive radiators as ports would probably be too long for a small box.

Is it realistic to design a bookshelf (or even a tower) with down facing subwoofer (6 or 8") that can do 30Hz and on the top would be just one concentric driver for high and midrange.

I don't have much knowledge in this regard. 🙂

Hi,

I am offering the following AKM ADC/DAC for sale :

40 pieces of AK4458VN 32bit 768kHz 8ch DAC (39USD/piece)

40 pieces of AK5554VN 32bit 768kHz 4ch ADC (39USD/piece),

bought from Digikey in Aug-2020 for prototyping which never happened after AKM plant fire.
Components still in original sealed packing, not opened yet.
Only for sale as whole packing (either type).

I have a pair but alas no circuit diagram, they are both working fine and show good 50k square waves stable on the scope and have equal low noise, but one is warm and the other is cool, so i need to do a bias adjustment, and also dc offset adjustment.

I've found 3 pots on the input/driver board, which I have no idea which ones what. One has to be for bias which i need to do, the other for DC offset which i also need to do and the third I have no idea what it does.
Does anyone have the info or a diagram on which does what. It's so dark and dingy down in there and cramped, I can't even see the emitter resistors so i can check the bias across them.

Your help will be grateful
Cheers George

It's my first thread here.

I have a Kenwood L-07 CII with a problem on the right input phono MC stage ( noisy with cracking... ).
But without diagram impossible to repair.
And also impossible to find service manual, schematic, information about, ...

Please I need your help !
Raymond

My preamp :

Anyone have a picture or know what the value of these resistors are ?

Is it ok ? or maybe it would be better to do the split to dual rail supply with zener diode ?