Morning! I am getting close (relatively speaking) to finishing up a TD125 with the SG4/MA-3D electronics that Pyramid developed. Since the SG4/MA-3D replaces the original electronics I am not using the original transformer.

I had a custom face plate made to keep the original strobe functional, but it's not lighting the way I have it wired at 120v. It looks like it the strobe actually runs on 220v.

Is it possible to run the strobe on 120v? With a different resistor than the stock one? Any insights on what that circuit would look like would be very appreciated.

Being extra cautious as I don't want to risk damaging the strobe.

I can get the Dayton sooner but would rather and will wait and avoid it if the mini is a good deal better..
https://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4-hd
https://www.parts-express.com/Dayto...gnal-Processor-for-Home-and-Car-Audio-230-500

Hello, I’m after a wide-band driver that will play from 150hz through to 15khz, as that’s the limit of what I can hear, but the key for me is that it’s smooth or controlled through the sibilance range as I am super sensitive to harsh S’s to the point where I get a headache very quickly if it’s not controlled which ruins music listening for me.

The problem is I don’t have the luxury of being able to demo lots of different full range drivers till I find the ones that suit my taste.

Are there particular drivers or types to stay away from or are there any clues to look out for in the published frequency graphs?

These speakers will be used for relaxing too after a stressful day at work at moderate to low volume and, I love a good stereo image with low level details and to hear the ”texture” on strings and vocals etc if that makes any sense. I have a pair of massive klipsch chorus for when I want scale and to party😊

Thanks in advance

Matt

A very newbie question here. I've never kept up with multichannel audio trends. However, I do know that I can't stand 4th order lowpass filters on subwoofers. Is it possible to use a custom lowpass of, say for example, 98 Hz, 2nd order Bessel on an external DSP while having a full signal routed to it? How would I do this? Thank you.

Hi

I am having a rather unusual problem with this amp. When I first got this amp, there was power but no sound. Upon observation, I realised that non of the tubes were lit. I left it aside and a little while later I tried again. This time, all the tubes were lit and there was sound. I kept turning on the amp every now and then and the tubes were all litting up. The next day, when I turn on the amp, again, they were all dead. After sometime, I tried again and the tubes were litting up as usual. I kept doing this for a few days, and it was litting up at times and dead at times. Finally I took out the board and resoldered the whole board. R81(470K) was blown. I replaced it. After putting back everything, I turned on the amp and all the tubes were litting up and the amp works as usual. I having been turning the amp on and off for the past few days and the amp was working OK. I rebiased the amp and finally decided to put back the amp in the cabinet. After that I plugged in a signal and let it run for about 2 hrs and turned it off. After about 3hrs later, when I turned on the amp, there was no sound and all the tubes dead( not litting up). There are 3 wires from the transformer for the filament voltage going to the board. Blue(3.15V AC) going to WP5, Black(0V CT) going to WP7 and Brown(3.15V AC) going to WP8. I pulled out the blue and brown wires and measured app 6.7V ac across it , but when I plugged back the wires to the board, the tubes were not litting up. I realised that the blue wire(3.15V) was very hot and had turned slightly brown at the transformer side. What can be the problem, is it due to a problem on the board or the transformer itself or the tubes. Please assist.

Thanks

I had been using this OB 4way active with 2 of minidsp 2x4HD for each channel, but due to my stupid action updating umik-1 firmware while 2x4HD was also connecting to my pc then suddenly killed 2x4HD but lucky still have another board. too lazy to send it back to HK for repair, then i convert it into 2 way active with ribbon tweeter use simple 1 capacitor filter and only use 21" woofer which was crossed around 320Hz with harsch XO. you might recognize these woofer in SBAudience brand

21" woofer https://acrspeaker.com/product/21-pa-113212-sw-fabulous-by-acr/
12" woofer https://acrspeaker.com/product/12-pa-75124-w-n-fabulous-by-acr/

when I read Troels ATS-4 which apply overlap woofer and midbass without hpf seems interesting idea which i might use on my OB. so i just import each driver frd and zma from datasheet using FPGraphTracer and play with Xsim based on troels xo value as starting point. attached is the result

my idea is that i will use this overlap style where 12" woofer will not have hpf filter then using minidsp 2x4HD will be filtered around 320Hz and powered by aragon2004. my estimated 21" woofer LPF around 80-100Hz with impedance correction. because i'm not so good at passive xo design so i'll need anyone input for each value that i use especially for inductor because i have to order custom size.

attached in zip file with xsim frd & zma used

thanks for your valuable input

can somone send me a schematic diagram for the gemini xg-1100 amp ?

Hello.I am making a simple 0.5A /35V psu with a 24Volt AC transformer ,4 diodeS UF4002 and a 2200uF capacitor. I was considering the initial charge current and if the diodes are ok to handle it or should i move to something like HER205? Simulating with a 100 ohm load to get an idea of the current pulses in each diode i got the image below.So how i select a diode with respect to these simulation pulses?

UF4002 Datasheet says :
IFRM Repetitive peak forward current of 10A
IFSM Non-repetitive peak forward current of 30A

HER205 Datasheet says :
IFSM Non-repetitive peak forward current of 50A

Hello,

I have drafted schematics in the LTSpice of the six LM3886 that could be a really cool project to attempt. Attached are simulation files and LM3886 model. Importing the model basically requires to copy it all into your LTSpice internal directories and then edit all of the files to correct the path string.

Hi all,

I am working on a TPA3251 project for a while with some good components like;
Inductors, 7uH Würth 7443630700,
Main reservoir caps, United Chemicon's 2000uF/50v 25mohm x 4
After regulator electrolytic caps, all ultra low esr polymer
Signal line caps, all metallyzed polyproplene and polyester type (no ceramic caps on signal line)
Decoupling caps, Elna Silmic 2
Opamps, OPA1656
Linear reg, ultra low noise LT3045 etc...
Also, its possible to make PFFB configuration with THT components on bottom side with point to point tehcnique. (because its too hard to make it with SMD components).
NFB lines are appx 55mm for each channel which is some long.. But the circuit can work without PFFB.
Anyway,
TPA3251, LT3045 and LM5010 chips are still available on Aliexpress market.
So I think its worth to make a good amp.
What do you think about my schematic and PCB layout?
Any comment will be helpfull.
Thanks in advance.

Where this the files UCDs of http://www.classd.fromru.com?

Thanks to ALL.

So I have noticed when people are using smileys that some look unusually fuzzy, so I had a look at the code and to my surprise they are linked to an external source, how come, are they using mobile phone and have selected the smileys Android or iOS have preinstalled or somehow pick an external link?

Here's one smiley example and there are a few more just couple a posts above from the same thread I was linking this quote from.

🤣

Click to expand...

That smiley in the quote is linked to: https://cdn.jsdelivr.net/joypixels/assets/6.5/png/unicode/64/1f923.png
It appears to be so that externally linked smiley is 64x64 pixels and gets scaled down on this forum and in the process becomes fuzzy looking.

And here's the same smiley, 22x22 px, which I picked from the smiley collection held on this forum.
🤣

so the first thing with this is one of the power supplies has no fuse in it and there is a broken joint on the bottom of the fuse holder
well it wont be that as its the 115v supply

For Sale a textbook Bruno Putzey balanced preamp, fully assembled. The issues with linearity of the volume control and high gain have been tackled with a mechanical coaxial control with gross and fine regulation and with a mechanical limiter.

Price 150 euros or best offer. Shipped from Vienna (Austria)

Why does this matter to my ear.
I hear great highs from NC500's class-D as good as good linear amps when driving say a nice even benign flat 4 or 6ohm ribbon tweeter with low phase angles.
But when the same amp is driving a speaker with not such a benign load I change my mind from nice to so so about the sound, and linear amps then sound way better.

Cheers George

OK, looking to start a project soon - an open baffle set of speakers - Dual Eminence Alpha 15A with a Fostex FE108EZ...kinda modeled / designed around the Emerald Physics CS2 and Martin King's Open Baffle White Paper. Had a pair of EP CS2 a while back after reading they were like Quad ESL-63 on steroids...well not exactly, but I was still impressed on a few things anyway (their bass and "Lively-ness"), and decided to someday build my very own...with a little tweak on the HF driver. I picked the Fostex as a few here believe it to be a great driver for HF for an open baffle setup, and also recommended in Martin King's white paper...

I have four channels of Hypex UCD400, so all good on amplification. Preamp is 6922 based tubed Music Reference RM-5 (great Phono stage) and source is an AMR DP777SE DAC connected to a computer and a Pro-Ject RM9 Turntable.

So the question -

I can do the DCX2496 doing the Crossover at LR24db/oct @ 1000hz for both drivers with EQ tweaks here and there, (with settings like the EP CS2), OR a Passive Crossover at LR24 db/oct for both drivers at 1000hz and use the DEQ2496 "correction" in the digital domain for LF and HF....

I guess I could just use both Behringer units too, so another option...

I also have the DBX VENU360, but I have yet to open the box and learn how to use it (I know, I know...sigh...)

Any advice to what is preferred? I understand this is highly subjective, but thought to just ask anyway...

I'm posting this from another site that he posted. I find this pretty amazing as this is a hobby for him and something he's doing out of passion. Check it out below and his website and YouTube channel. He has great info! Also, if you want to send him speakers to measure, keep in mind that there's no cost to you.

-----------------------------------------------------------------------------------------

Well, after months of back and forth, looking at expenses and trying to predict the future, I finally did it...

I have acquired a Klippel Near Field Scanner!!!!


As some of you have seen me say before, it takes me 10+ hours; sometimes literal days. The NFS will cut that time down significantly and provide even higher accuracy data. I should be receiving it hopefully within a few weeks. I am awaiting a shipping date from Klippel but I just sent payment for shipping/import fees this morning.


It's going to take me a long time to pay this off... at my current YouTube revenue rate it may be 10-15 years (I have literally been averaging $10/day; which is nice but it is nowhere near enough to make a living from). So, it should be apparent (if it wasn't already apparent) this isn't about money for me but about passion. Frankly, if I were in this stuff for the money then I would just throw up subjective reviews like so many of the other reviewers and knock out a review per week. That's not a knock against those guys... plenty of people watch and appreciate that content. But that's not my goal with my channel/site. For me it is about gathering evidence (data) and using that to help draw meaningful conclusions about what we as listeners like and prefer and then use that knowledge along with future data to help inform in order to make purchase decisions that make more sense for us. I am trying hard to do my best to provide objective and subjective; that's my real goal. And I think I do a good job but the NFS will allow me to take it to a new level. This isn't my full time job but I work just as hard at it as I do my day job.


As I've said before... if I can just break even, this is a great way for me to pass the time in a meaningful way. I get to play with cool toys. I get to make more friends. I get to learn. I get to grow. And, maybe, if this passion doesn't wane (it hasn't in my last 15 years) then it'll be a hobby for me after I retire from my real job. And the community benefits with great data. The data can never replace hearing something yourself (because tastes can change, etc). But I am a proponent of good data to help us build a better understanding and filter out the junk from the "maybe" pile.



Now, I'm all in on this and payment is being taken care of on my end. However, I have started a PayPal contribution page for those of you who have the means and have found my efforts useful enough to warrant contributing to the cause in order to help me at least offset some of my costs. I know times are tough for everyone so if you can't or simply don't want to contribute, hey, I get it. Like I said, it's already a done deal. But if you are able to help just know that I am extremely grateful for anything you can help with.

Erin's Audio Corner
Erin's Audio Corner - YouTube


If you want to help contribute to the cause the link is below:
Contribute to Erin's Audio Corner Klippel NFS Fund

Full disclosure: Erin did come on my podcast and that episode is coming soon so please subscribe to my YouTube channel! 😉
The Intellectual People Podcast - YouTube

I am attempting to repair the volume control on a damaged Rega Mira 2000 integrated amp that I recently required. The volume control is a 20 step mechanical rotary encoder with a built-in button that switches to input selection when the shaft/button is pressed (original was bent and damaged). The encoder controls a motorized pot within the amp. Thinking that rotary encoders are standard parts, I ordered a 20 step Bourns encoder with the same dimensions as I couldn't find the original Alps unit. It works fine, however the direction is reversed when turning the encoder; turning it clockwise decrease the volume and the same with source selection. My initial thought is to cut and reverse the traces to the pins on the encoder, but if there is a more elegant solution or maybe a different part that I'm not aware of please let me know. I've attached the schematic I have of the main PCB, the encoder is on a daughter board not shown that connects via the SK3 connector shown in the schematic, this is the encoder that I am using as a replacement.

Hello,

Anyone have a stash of NOS or working used vintage audio transformers they ware willing to find a new home for?

Seeking 2 each of the following hopefully at a reasonable cost:

1. Triad HS-56 transformer
2. Triad HS-26 transformer
3. Peerless S-217-D transformer

Shipping to San Francisco CA.

Thanks in advance!

Greg

High Fidelity Performance Op-Amp.

No need to make too complicated
when such good results with fairly simple 3 stage circuit

Set up this amplifier design model
in your simulator
and you will see!
🙂 And why not layout your own Hifi Op-Amp PCB
and make a few small killer OPamp devices of your own.

Version 1 of mine used 17mA current total
at +/-15 Volt DC
and tested for practically 0% THD distortion, in various loads and output voltages.
Fourier Analyse shows very nice even spectrum of harmonics.


Regards
Lineup Audio Lab Productions

I just want a decent make - Sony / Kenwood no bells and whistles like apple carplay or GPS, but touch screen and Bluetooth, head unit availed in UK please 🙂

My midrange stopped working, I suspect it might be the resistor. Does anyone know how to check / replace the resistor?

This is the resistor I am referring to (mid-range): http://parts.wilsonaudio.com/resistors-for-the-watt-puppy-series-7/

¿Qué pasa amigos? ¿Hay un equivalente para los fets fb3307z? Son de un amplificador kicker dx1000.1. No los encuentro en mi ciudad y quisiera saber si existe un equivalente. greetings friends

I have for sale paper in oil tin foil 6 pieces of 0.1uf and 4 pieces of 0.47uf this truly verry good sounding caps. This are new old stock. Never used and new. They are no longer in produktion. Verry natural sounding caps. Price for 0.1uf is 20 eu for a piece and 30 eu for one piece of 0.47uf plus shipping inside EU. I accept paypal.

Hello,

This will be my first speaker build. Would like to try out a full range bookshelf as I don’t have the space for towers. I don’t mind adding a small subwoofer down the line if needed. Is the maop 11 a good choice?

I would be interested in good mids and highs if possible.
Thanks.

Bought from Future Electronics several years ago -- IXTH50N20 (obsolete) N-Channel +200V, TO-247 gfs=32 Siemens. IXTH24P20 -200V, 15 Siemens TO-247. 5 pieces of each, $10 takes the lot (10 pieces) Shipping included to continental US via First Class Mail.

Hello!

Why are those tubes so expensive? This seems to be over the top....

Hi,

I would like to build one of the First Watt DIY amplifiers to power my Ron Clarke Austin 126 Rear Loaded Horn speakers. The speakers are using the Fostex Fe126en drivers.

Please could someone point me in the direction of which of the First Watt offerings would be most suitable?

Thanks in advance for any help.

Hi all. Being sold by the pair, the famous (ha) open baffle woofer.

Driver info page here.

• $150 per pair, plus shipping (from NY).
• Buy three pair for $400 (six woofers @ $66 ea.).

New in box. This is leftover from a larger order, which I didn't end up using.

I'll be posting several threads here in the upcoming week, selling such leftovers.

I've made many sales here the past couple years. You can see my work here: www.aforara.com

Thank you for lookin' and have a lovely day.

Since many of you on here build your own DACs, I thought you might be able to give me a clue to what's wrong with mine. It's an older Musical Fidelity A3.24, which was one model down from their flagship when it was made. For several years, it sometimes makes a loud 'pop' when I insert a new CD into the transport. It does this with different transports, but it's currently hooked to a Pioneer Elite DVD player.

When it does this, the "Locked" LED on the front panel blinks. But it doesn't do it every time a new CD goes in. I haven't been able to discern any pattern to it. I've just gotten into the habit of muting my preamp every time I change CDs.

Are DACs supposed to mute any un-musical signals related to getting a digital signal lock?

anyone familiar with this amp? Schematics? Cannot find any model number.


Thanks.

I would like to create a list of speakers fit a 2nd generation Tundra, NON JBL no navigation.

Did you install one which you are happy with? Did it fit right into the door? Please, help us who want to upgrade the speakers.

Hi all, I have a skar RP2000.1 that is kicking my butt.

All output fets and power supply fets have been pulled. All drive transistors that drive the TL494's output to the gates of the power supply fets have been swapped as the originals were toasted.

When I attempt to power up I can see the gate drive being setup for a fraction of a second then it shuts down. Pins on the tl494 that raise red flags are pin 3 and 16. Both start out at 0v at power up and then swing to 3.81v about 2 seconds after REM is given voltage.

Here are all the TL494 pin voltages. (Second voltage if noted is after 2+ seconds of power being on rem+)

Pin 1: 0
Pin 2: 3.81
Pin 3: 0, 3.81
Pin 4: 3.81, 0
Pin 5: 1.05 (weak oscillation)
Pin 6: 2.59
Pin 7: 0
Pin 8: 11
Pin 9: gatedrive for a quick moment, 0
Pin 10: gatedrive for a quick moment, 0
Pin 11: 11
Pin 12: 11
Pin 13: 3.81
Pin 14: 3.81
Pin 15: 1.37
Pin 16: 0, 3.80

There is also a nearby LM393 whose pinout reads:

Pin 1: 0, 3.65
Pin 2: 3.81
Pin 3: 5.67
Pin 4: 0
Pin 5: 1.86
Pin 6: 1.29
Pin 7: 0, 3.81
Pin 8: 11v

Attached is a picture of the area.

I'm looking for a subwoofer for a sealed enclosure with maximum volume of 8ft3 that naturally has bias to 30-40hz with less SPL at 60-70hz. I'd like decent max SPL. I've collected every model in the price range I considered in the attached table. I left off the brand names to reduce brand-bias. I'm leaning towards the woofer identified as "K" in the list. which do you think meets my criteria the closest and why?

I recently purchased a REL Britania Subwoofer with an amplifier that needs repair or replacement. The amp turns on and seems to work for a short period and then stops working - when working there is a constant static hum. When the sub stops working the driver sometimes continues to move even after music is turned off. Sometimes the relay (I think) clicks on and off repeatedly. Basically I think there are likely multiple problems. I've ordered a new relay and new resistors to replace the ones that show signs of overheating but those resistors appear to be in speck so I'm not sure that will solve my problem(s). I'm starting to think replacing the amp might be a better solution and I've started looking at plate amplifier options - specifically the Hypex Fusionamp FA501. Looking for opinions on how best to proceed. Assuming I'm unable to fix the Rel amp do you think the Hypex FA501 would be a suitable replacement? How challenging is the calibration and filtering?
Thanks all!
James

​

Very rare and special big Siemens caps Mkp 100mF 700Mkp Siemens 100mF 700V . Price €.50 unit

ar sugden connoissuer bd101 turntable

anyone know anything about this tt?

I can see mention of the bd1 and bd2 and some older idler drive tt's but no mention of the bd101.

Can anyone shed any light on it,

TIA 🙂

hi,

using a class a amp +/-45v@2amp will be more then 180watts per channel, we have 0.94% trafo efficiency and 1.4volts drop on the rectifiers
90/0.94 + 1.4=97.2volts; 90/97.2= 92.6% total efficiency for the power supply.
THEN WHAY TO USE A SHITCHING POWER SUPPLY?
Did I calculate wrong? What are the benefits of switching power supply when using class a amps?
Best regards

Williams

In accordance with Fourier analysis, the leading edge gradient of a transient sound reproduced by a loudspeaker is defined by the high frequency response limit of the system; it is reproduced by the HF, not the LF driver. Given that our hearing deteriorates with age, this could be viewed as applying a low-pass filter gradually reducing perceived HF content as we age, and thus, theoretically, the leading edge gradient of a transient as perceived. (Considering a square wave signal, lowering the filter cutoff would eventually leave us with only the fundamental sine wave).
Imagine a listener who is unable to hear above a 5kHz pure tone and we play an unfiltered piece of music to them. Would this subjectively sound identical to the listener compared with the same piece of music having a 5kHz low pass filter applied, with particular regard to the perception of transient sounds? Phrased another way are we able to discern the difference between being unable to hear above a particular frequency compared with the absence of that HF information in the source, again considering only the perception of transients?

hi friends. i want to learn this if i use smaller transformer for amplifiers need.

exm. 500w power amp and i use 250w. what can be happen? transformer get damage or just amplifier working half power?

For sale four F4 Boards / see at Peter Daniels Group Buy. Boards are full functional. I used them as a balanced version over many moons. All four F4 boards full populated including the Power FETs. Boards used before and all working without any problem. Including the sales are one Power supply Board (PSU size 170mm x 170mm) assembled with 8 Capacitors 27000uF/25V and 4 Capacitors 6800uF/35V and one Softstart Board.
Toshiba FETs 2SK170BL / 2SJ74BL for all Boards available but not included. All FETs I bought from Spencer. I have 2 complete F4 balanced Sets available for sale.

If anyone is interested, please drop me email, asking for all 175€ + shipping. Offers are welcome. Payment through PayPal you must pay additional handling fee 4%. Insured Shipping anywhere is a must. I think it will cost around 28€-45€ worldwide.

For sale a pair of new, never used, celestion AXi2050 engineering sample working perfectly and in their box. Selling for a friend that switched from horns to full ranges. AXi2050 are 2" drivers capable of covering a large spectrum from the lower octaves ... considering reasonable offers. Shipping from Italy so EU buyers preferred.

Does someone have a way to contact Werner Jagusch about his crossover design for the Altec Flamenco?

Thanks,
Jim

Hi, this is in a Hifonics A3000.1D car amp. These two components come directly off the Line In RCAs. T101 and T102. I think maybe they are inductors or choke? I'm trying to source a suitable replacement. Kind of hard to see but the board is black next to both of them.
I'm trying to fix this for a friend, I can handle the soldering etc just need a part.
Thanks I appreciate any feedback or suggestions on where to look!

I'm re-capping my NAD 3140, and there appears to be a discrepancy in the parts list vs what's actually on the board.

Looking at the parts list, C643 is a 3300PF 50V mylar cap, but on the board I think it was a 47uf 100v electrolytic cap. Unfortunately, instead of documenting each cap as I removed it and ordering based on what was on the board, I ordered off the parts list, and didn't realize that I had a mismatch until half way through.

Also, there was a group of caps in the regulator section that were fried looking, with dark, melted off wrappers. Is there any way to upgrade this section to prevent it from burning out?

I have some pictures attached.

Looking for these.

Is there any web sites or plans anywhere for building a somewhat high end turn table? I'll buy the arm and am looking to spend around $3-4k total. thinking about just buying a used VPI but if I can build something comparable Id go that route. I am a journeyman level machinist/ mechanical engineer with access to a full on shop.

Well this interesting thing popped up on a local audio sale page. ($488) No info just a couple pix. (I have requested more info). It's likely from Japan and I'm pretty sure the seller will know nothing about it. Home-made? I am curious what you might think about it. I am not an engineer type, but am very curious what's going on here!. UPDATE... He says"" It work . This design same Audio note but AudioNote upgrade power tube 1 more and improve tube pre for 2 right n left"".....He seems to be saying it's based on the Kondo M7, but is better!

FS: Full Soekris DAC kit with Amanero USB Interface and Audiozen Control PCB and all parts

For Sale complete Soekris Dac kit, including:
-Original, not modified Soekris DAM1021-02 R-2R DAC PCB (0.02% resistors, no longer available, still sell for 230U$ for 10% resistors...)
-Parts to mods to Soekris Polymer 820uF caps, and smd resistors.
-Amanero USB interface (original), current price 85U$
-AudioZen, rev 1.2 assembled Control PCB (just need to solder the connectors) and Display kit for Soekris and Amanero (includes also all the extra needed parts, Toslink Receiver, connector, cables, otuput connectors, etc....), original price 150U$ + 150U$ of extra parts
-Also included at no cost 'Universal Signal Isolator' Rev1.2, for Amanero
-All docs for assembly and test.

So you have all the needed parts to build the great Soekris DAC, just need to add an enclosure...
As I said this kit is brand new, never modified or assembled
Will be double boxed for safe shipping

Asking price is less than cost of parts and the 2% resistor DAM1021 version is no longer available. My loss, your gain...

Asking price 550U$ + shipping + Paypal 3.5%

can you rec'd a one channel mic preamp good for measurements

i want something similar to rolls mp13

i currently using a leem pra-12, i think it is a poor copy of the rolls

I picked up this amplifier as part of a lot of items at an estate sale. If anyone can identify the circuit and determine what tubes it requires, that would be helpful. There are no markings or brand labels anywhere on the unit. Thanks in advance.

Say I want to see very old posts by a specific member. I can easily see about the last 100. Then I hit a "View older results" button, which does not do what it says.

Try me:
https://www.diyaudio.com/community/search/member?user_id=5094
At the bottom of the first page of links, I get "1 2 3 ... 10".
Skip ahead to 10. At the bottom of that is the "View older results". Which does not get past page 10 (or for me, a month ago).

Should we be looking to a future instead of into the past?

Hi folks! This is my first post on diyAudio. I'm a college student, and have been into audio for over 10 years, and only finally am I making plans to start with DIY speakers. I would like at some point to get into making my own designs, but for now, I am thinking of following another designer's plans. I'm looking for some impressions on Carmody's Redux speakers. Are these any good? They're a bit of an older design, and a lot of the impressions I've found online are also pretty old. Do they hold up today? Are there other, more recent designs that sound better for around that price range? Thanks in advance for your input! (By the way, I am very interested in open baffle, but am willing to forget the idea if the quality wouldn't be up to par)

Hi All,

I'm not at all new to electronics DIY and I have some experience with very basic woodworking and access to appropriate tools. That said, the last time I tried to build a speaker cabinet it was in the 9th grade with mitered joints and cleats and, well, let's just say that I didn't get very far.

Ok, that out of the way, being all grown up (outside) and motivated, I've decided that the MTH30 seems like it will be a good companion to my alto TS110s and I want to shake this fear of cabinet building as I have some other projects where ultra-budget is essential.

So, if you guys don't mind, I have some really basic noob questions.

1) I see that the MTH30 calls for MDF. I would rather use plywood for weight, is this a good idea? If so, does it require changing the plan in any substantial way? Any experiences with plywood vs mdf would be helpful here. I don't care about the additional cost if it makes the cabinet lighter.

2) Are the cabinets glued and screwed, or just glued, I can't tell from photos online. They appear to be just glued.

3) From the pictures that I've seen, I'm not seeing anyone line the cabinets with the acoustic dampening material that was found in virtually every speaker made when I was a kid. Do you not need/want this in these type of cabinets? Don't laugh, I really don't know the answer.

4) I'm in the U.S. so getting one of the called for drivers is a bit expensive. I've seen that people have used at least two different alternative drivers that are available from parts express. The RCF LF12g301 and the Goldwood GW-12090. The RCF is $199 and the Goldwood is $99. I also have a couple of JBL tops with 2206s in them that I could borrow temporarily to try out and compare. The question is, what differences should I expect between these drivers? I'm really new to this so I don't yet have any intuition on translating driver specs to real world differences. So, if possible, please be specific and discuss in terms of real world performance differences. I'm not adverse to buying the right driver, but I don't want to waste money on differences that I can't use. I care a lot about sound quality, I care a little less about maximum output.

If it helps this (or these if I build two) are only going to be used for DJ applications, both indoors and out, for small gigs. I largely play somewhat downtempo as well as classic house music, if this helps understand my application. Also, you can assume that they will be powered with an appropriate amp for the driver, so that isn't a factor in which one that I choose.

Thanks in advance,
gs

I have a few chassis that could use new amp circuits. Power supply voltages range from +-60 and +-85V.

2017 Sanken 2.0 Stereo Daul channel HIFI Power amplifier board Finished 500+500W | eBay

Any recommendations would be nice!!

Hello!

I'm considering building my own speakers to go in my living room. The living room has a suboptimal shape - it's rectangular, 3 14' walls and a large opening to the hallway/kitchen/rest of the house:


The speakers will go near the fireplace (labeled FP), so one in a corner (sucks but that's the layout of the room), and the other one about 8' from it. Listening distance would be ~12' from the front of the speakers. I mostly listen to electronic music and rock/metal. Sometimes I like to go loud (have measured close to 100dB in the listening spot. I don't do this often but I want to be able to do it). Adding a subwoofer (either purchased or DIY) is an option I am certainly okay with. No particular size/aesthetic requirement, I want it to be fun to listen to. My main system right now is a pair of Genelec 8330A and a 7350A sub, which I use on my desk. I absolutely love how that system sounds - the room correction is pure magic. And I like the analytical sound of studio monitors, but not attached to it.

In terms of amplification, I have not made up my mind yet - I will need to purchase an amp (or multiple). I have a MiniDSP 10x10HD available that I can utilize for this project if I wanted to. Budget wise, I am hoping I can get decent results with $2000-3000 - that goes towards wood, speaker elements and maybe a crossover if I go the passive route. Closer to the lower end of the budget is preferred. TBD about amplifier budget - I could always start with cheap amps and upgrade later. Most of my music comes from Spotify and Soundcloud, although I do occasionally listen to 24/96 FLAC recordings when I can get them. I am not yet sure which source I will be using for this living room. Would likely start with a Chromecast audio and some DAC via the toslink connection.

I have some woodworking experience, and have access to a professional, well-equipped wood workshop - so pre-cut kits are unnecessary. I also enjoy learning new things and playing at the shop.

I tried searching around for plans that fit my needs but there is an overwhelming amount of information, sometimes contradictory. I was wondering if anyone could stir me in the right direction. I am also open to purchasing speakers if that is the best use of my budget, but I am thinking that I might be able to get more bang for my buck by building my own, given that I don't put any value on my time as this is a hobby for me.

Thank you!

Just noticed this...


-Casey

In the audio realm we talk about “beaming”, “directivity”, “lobing” and “breakup” in speakers. But I find that few people understand what it means. So, I asked René Christensen of Acculution to join me and explain. In the video below, René breaks down the math and gives us practical examples, showing how cone geometry and materials can impact radiation and resonance in transducers.

Please leave a “thank you” for Rene and make sure to leave suggestions for future topics you’d be interested in seeing.

(FWIW, my “interview” videos are not monetized)


Login to view embedded media

Fun rebuild I wanted to post about.l and for others. I just received this amp in as part of a larger trade/buy. Classic powerhouse from 1999! Punch 800a2, not the fabled 1000a2 but still 🙂 From those I’ve talked to so far this looks to be a common problem, so figured I’d post repair process, and in case I come across any problems while doing so.

Looks like entire channel has blown, all output FETs bad, some even got so hot they lifted off the MESHA plate (another 1st for me🙂 all resistors on that side all wonky, both SMD and Throughhole types, 2 banks of BJTs look toasted, even a nice crater burned into board (but not all the way through, other side of board looks perfect actually) might need to rebuild some traces(another 1st), even the ceramic capacitor near output terminal has a hole blown through it ...needless to say a lot of firsts for me and excited to dig in on this amp.

Already have some parts on the way.

0.1Ω 5w metal oxide resistor x10 (large t-hole)
5k potentiometers and remote spade terminal
Researching BJTs currently, as with everything

I had some questions regarding the Power Supply and Output FETs. IRF640 and IRF9640, should I stick with NOS FETs of the exact type or is it advisable to go with the replacement N types (IRF640N/IRF9640N) ive been told to but I’ve also been told they cause problems on this board. Any personal experience greatly appreciated, this is more of a learning experience, 1st timers, fun project for me so time is not a factor, so I don’t mind sourcing original parts (640 seem to be hard to find atm) but any other advice/direction/better alternative then stock parts would be awesome to hear about.

I’ll post more as I make my way through amp, currently mocking up a sketch of amp, damaged parts list, stock parts and locations, probably going to recap with new better caps as well, but making notes of everything to do it proper.

Hi guys!
For almost a year, I was considering building a tube headphone amp. I still don't know, what design to go with. OTL or with OT. What are your thoughts on OTL? Are they really better? And do they also sound good with low impedance headphones? And if should I go with OT, what OT should I choose? I know that for headphones, I need amp that has at leats 8 times lower output impedance than headphones has. So should I use OT with 32 ohms secondary or 4 ohms secondary? Thanks!

Not sure if you have seen this, not much data yet but looks interesting:
Drivers & Amps - Peerless

LCPF600 Amplifier Module:
- 600 W, 3-channel amplifier
- Active PFC + LLC SMPS
- Current, voltage, and temperature monitoring

LCPF1200 Amplifier Module
- 1200 W, 4-channel amplifier

Hi,
I'm setting up an audio lab to test speakers and speak enclosures. Any suggestions on what microphone to get to test speaker audio frequency response. Also, recommenations on software to plot frequency response, thanks!

I'm trying to manipulate the box design for my JBL 2225h with limited success. Has anyone had success with JBL 2225 in an ONKEN enclosure using the http://mh-audio.nl...? if so, had you had to override any of the controls to arrive at your target Bv.? Modifying the box to accommodate the ports to get to a reasonable box dimension and shape has been my problem. I get 8 ports 28" long by 4.5" wide and in order to fit the 4ports per side of box, the front needs to be 58" tall. from a volume of 4.14Ft. Cu. the box will only be 5.6" deep at 24" wide. Unless me figures are wrong this is my issue.
Any help would be appreciated. Thanks

kingfisher

Hello group,
I have a VOX DA10 that is motorboating and will not power up. It looks like the Caps are fine but I can't do much with the power supply without a schematic. Thanks

Is there any long term downside to using hot glue to secure components to a chassis?
I'm thinking mostly of capacitors that are a little too bulky to rely solely on a point-to-point connection.

I've owned my Super-T for a couple of months now and I've recently swapped from some home-made speaker cables (based around co-ax wire) to some QED multistrand cables. The difference in sound between these two types of cables is almost too small to measure.

Does this mean that these amps are not so dependent on the quality of speaker cable or is there a specific cable I should be using.

Hi Folks,

Iv scoured Martinssons blog and the forum here looking for updated plans for the tham15 that have the added reflectors and therefore slightly bigger horn mouth.

Is there any conclusion as to if this update had any benefit? If so are there any concrete dimensioned drawings for the the MKxx update?

Hi,

I was wondering if anybody had worked through the' Loudspeaker Modelling & Design' book by Geoff Hill. I've been using it as a guide to look at driver design, specifically subdrivers, but I seem to be coming across a lot of errors in the math & modelling.

Has anyone else encountered this and been left similarly stumped?

Thanks,

Anyone got a schem for this UK installation amp. Local agents are unable to supply information. NOT user manual (just want to repair it, not use it 🙂 ).

If anyone has PCBs left and want to sell them, please PM.
Thank you

Need Help With EZ80 Rectifier for DAC

I am teaching myself some tube knowledge and thought I would start with a clone of the Border Patrol DAC. I know that DAC uses off the shelf XMOS and DAC boards with no output buffer so that portion is simple. The DAC board power supply must be between 11-20V DC.

As shown in the attached photo I found of the DAC internals, the power supply is an R-Core transformer fed into a circuit having an EZ80 rectifier and what I think must be a diode rectifier because the tube can be switched in and out of the circuit. The attached photos show the heater and filament supplies (red and grey wires) to the tube rectifier PCB. There are two center tap wires (white wires) from the transformer directly to the ground on the DAC board. The rectifier PCB has a pair of diodes and a pair of resistors at the bottom, a pair of tantalum caps and a third resistor having a stated value of 10k (the bands indicate the actual resistor value is 4.7k 5%) that is maybe for current limiting. The rectified power (black wire) then passes through a choke and then to the DAC board. There is a cap across the V+ and ground at the DAC board inputs.

So this is the total of my knowledge of the power supply. Can anyone help me figure out the rectifier schematic and the proper component values and voltages for the transformer supplies? I am think about just using the EZ80 rectifier without a switch for taking the tube in and out of the circuit.

Thanks in advance.

Hello. I just joined yesterday. I saw a youtube video with Nelson Pass being interviewed and thought this sounded like a great resource.
I am currently taking apart one of my Adcom gfa 555 amplifiers. White fluid began leaking from the bottom and when I opened it, I saw that it was coming from the transistors. Or rather the thermal paste from the output transistors. In order to clean it properly and not damage anything, I have to take apart the rear a bit and I wanted to test things like capacitors and any other parts that are known to go bad. I was thinking that this would be the perfect place to ask about it, since I’d read that Mr. Pass designed these amplifiers.
If there is anyone out there who would not mind sharing some information, I would greatly appreciate it.
Please do not tell me not to do it. I
Am on here seeking information about this equipment.
I do not wish to pay a shop hundreds of dollars. They quoted me $200 a few months ago to change a fuse.
I decided to do it myself. Some weeks back, this particular amp had a burning odor coming from it. Not smoking, just like the smell of plastic heating up.

I’m also building some external crossovers for my Magnepan speakers. Still waiting on some parts I ordered a couple of months ago.

I recently purchased a digital multimeter, a soldering iron and yesterday purchased an lcr meter.

Thank you very much, in advance

Best enclosure for that driver?

Sometimes I see people looking for type data of ILP toroidal transformers.


This is an old sheet. I post it here before the mice eat the rest of the paper.


In Dutch Type nummers ILP ringkern trafos.

Hi people,

I pulled these Transistors out of a Kenwood KRF-9080D AVR. As I'm just a mechanic (and still a newbie in diy-audio), I'd like to ask you what I could do with them? I've read the Datasheet, and know those are a little "special".
Is it possible, to use some for a Subwoofer-Amp (I'm building one atm with IRFP240/ IRFP9140, but havn't tested it yet)? Or could I use these Transistors in a Cap-Multiplier? Or, if there is a market, should I sell or swap them?
What would you do?

best regards
J.

Hi! I may be of topic but i didnt now where to put this,

I recently got my hands on a NAD C350 integrated amp.
(home stereo).

But the amp goes in protection after 2-3 seconds.

I have checked the output transistors and they seeme to
be OK.

And i checked the drivers, and the seeme to be ok.
A litle hard to measure because the have mirrored
the pins on that transistor modell.

I removed all the drivers and started the amp.
And i got green light! 😉

But what the hell? I measured them and there is no
short from what i can se. they all measure about 0.6 in
diod check, and same for the outputs.

Anyone have a clue what could be the problem?

I saw inside the case that signal earth had been repaired
for a couple of years ago. And i saw a fixed print. But cant
find anything that looks broken.

But you can se that the board is a bit darker around
the drivers and then there is 3 other transistors.
But none of them seemes to have a short.

Hi guys ! I need a diagram ( amplifier circuit) ! Can someone share??? I have leftovers after the accident --- I want to restore! Manley Jumbo Shrimp

Hello
I have a problem with my Oxygen Audio AirPro M2.5K amplifier.

When I turn it on, the green indicator lights up then the protection indicator lights up and its without the power MOSFETS.

I did some tests = a 7812 HS regulator and at the driver board level I had HS transistors such as Q5 Q9 Q12 Q6
Do you have any ideas of what to try out?

Q5 is DK mark QF is it 2SC4672?

What about Q9 2SA1797?
Where can i find them or any substitutions?

Thanks a lot and sorry for the language it's google translate.

Hey people,

could I use this for my MIVOC AW 3000 SW?

best regards

Any source for CCS boards/kits? I've used K&K ones in the past but I'm having a hard time reaching him and he is not responsive on his forum board.
I'm planning on using them on 5687 tubes.
Not skilled enough to create my own.
TIA