SOUNDSTREAM OLD SCHOOL AMPLIFIERS
Hello, my name is Wade Stewart. I am the engineer that designed and manufactured all of the Old School Soundstream amplifiers and crossovers from 1981 through 1998, all REFERENCE, CLASS A’S and old RUBICON amps. I am here for any discussions, questions or any other need you may have concerning old school Soundstream amps and crossovers. I also offer Schematics, Owners Manuals and Repair of any older Soundstream amps.

I've started my Half Changs. I'm using 18mm "maple/birch" ply that I found at my local Lowes. It turns out that the ply has a birch veneer side and a maple veneer side . The birch side is very erratically figured so I'm going with the maple side. The drivers will be FE206s - that pile of blankets in the background covers them as they are burning in.

As you can see, the cabinets are all cut and the driver hole has been routed. I'm waiting on the delivery of a 30º chamfer bit I ordered from MLSC to finish the holes before assembly.

That gives me time to start asking questions and soliciting advice. Specifically:

- Damping - right now I'm planning on damping the rear, top, bottom and one side of the chamber to start. I have some polyester batting but was intrigued by the use of cork in the recent PAWO thread. I'd appreciate any advice/opinions about my damping locations and choice of materials.

- Bracing - I'm planning three internal braces. One horizontal offset behind the speaker, another window brace a little more than half way down the chamber, and a vertical brace from the lip of the vent slot angled up to the front (like Marce used in his Curvy Chang). Should this last brace be offset or centered? Again, any comment or advice is welcome.

- FE206 prep - the drivers already have about 36 hours of burn in and should easily have 100 by the time I'm ready to mount them. Dave has told me that he's now working on a 2nd gen of 206 mods (EnAbl, etc) so I am holding of on any intense mods right now but will be adding duct seal to 3 of the 6 arms and a felt pad to the rear of the magnet. It would vastly improve the WAF if I could color the cones flat black or very dark brown, Dave has indicated that his new mods may allow black gloss acrylic in the final stage and though I'd prefer it not to be shiny, I might have to settle. Has anyone out there successfully dyed or stained Fostex cones and dark color? And, if so, how? Scottmoose has suggested ~4 ohm series resistance so I will try that, also.

Work, family and waiting for the router bit will mean I won't get back to these for a few days but I'll post again once they are partially assembled and ready for damping, etc.

I'm working with a Hifonics Zeus 3200-1D and I'm searching for illustrations and data sheets for this amplifier repair project,any info will be greatly appreciated

Good morning everyone.

I want to preface that I have already done a lot of searching and reading on this subject but obviously quite a lot was over my head and there is incredible abundance of information to sift through. So I do apologize for asking something that is well covered and likely well understood by most members. Thank you in advance.

On to the situation. Long story short, I've always had a huge appreciation for music but never had the budget for a high quality setup so I have mostly stuck to midrange headphones and vintage scores from CL and the like. This has been adequate so far and has greatly surpassed what's available to average consumers at a reasonable price. My daily driver for the last 8 years or so has been a 1968 HH Scott 2550-W "Scottie" with its proper enclosures that I scored for $50. The drivers were smoked when I got it so I grabbed some 6.5" paper cone boses from the parcel shelf of a Mazda Millenia when I was at a junkyard and by mostly luck, these have been a great fit for the system. Its a bookshelf SS unit so I know it's not creme de la creme but it does sound great to my ears when placed well in the right sized space. The highs roll off a little early and bass extension isn't anything to write home about but it does blow the doors off what most average people would consider "quality sound" and is very pleasant to listen to for extended periods.

All that being said, the unit just runs out of steam in a larger space. My SO and I recently became home owners (finally, hooray) and I now have a much larger space that I need to fill with quality sound and the shortcomings of my setup are more apparent than in the past. I know that replacing a 10wpc with a 7wpc amp for a larger room, is a little backwards but I'm hoping with high sensitivity drivers and well designed enclosures it will work out how I am imagining.

So for amplification I'm planning on a cheap chinese SE EL84 unit. I know that I love the tube sound from a couple guitar amps that I have and I'm ready to splurge a little bit and dip my toes into the water. The unit in question is a Reisong A10. They are absolutely terrible out of the box with nearly 10% distortion at 1w output but with some simple modifications they can perform well up to 6-7wpc. I know this is a gamble but after watching Skunkie Designs youtube series fixing this amp, I am pretty confident it will be a good performer afterwards and a risk I am willing to take. I'm new to enclosure and amp design but I'm very handy with a soldering iron - everything from microsoldering on phones to building LED grid arrays for aerial advertising.

My room setup is funky. The main listening space is 14' wide by 20'ish long with a vaulted ceiling starting at 8' high on the left to 11' on the right. There is a large opening on the right side of the room that goes to my kitchen and dining room and would like to be able to pass music through to enjoy while cooking. Not ideal conditions but that's what I'm dealing with. I would like the enclosures to be close to the wall. I also know that I much prefer paper cones compared to other construction methods.

Given my constraints (full range, open sound stage, good dispersion, high sensitivity, paper cones, budget friendly, placed close to wall. needs to fit in with MCM furnishing) it seems to me that a Pencil setup with 4ish" drivers could potentially fit the bill. I have read through some of the blind driver comparison threads to get an idea of what people like subjectively and to then look at the specifications of said drivers to try and find a fit.

First up are a couple of Faitalpro offerings.

The 3" 3FE22
Pros - Very cost effective, good sensitivity, excellent off axis FR.
Cons - Bass rolls off quite early at 250hz and without a tried and proven pencil design (that I could find) for this driver I wouldn't know where to start dimensions wise

The 4" 4FE32
Pros - Cost effective, good sensitivity, very good off axis response, good response down to 150hz
Cons - off axis performance slightly reduced compared to 3FE22, same issue of enclosure design

Then there are a couple Mark Audios, the Alpair 10p or 12p
Pros - Proven, available Pencil enclosure designs, highly regarded by the community for quality etc
Cons - less cost effective, less sensitive, less off axis performance and they are apparently intolerant of poor amplification (I hope for this to be inconsequential but remains to be seen)

So long story short I guess my questions are:

Does a pencil design suit my use case? Am I on the right track regarding driver selection? If not, what would you suggest? Is there a good pencil design available for the Faitalpros?

Thank you all, this site has been a great resource so far and thank for taking the time to post on here, it has been immensely helpful already.

Hi from Christchurch, NZ. I'm trying to be retired from electronics design but I've got to keep my brain ticking over. I am here due to finding a very helpful post describing how to fix the problem with my Keysight oscilloscope. Perhaps I may be able to return the favour by sharing my wisdom.

Hi all

New here and hoping to start a build for 2-3 subs with your help. Have build subs before, its not the skills that I need help with but the technicalities.
My goal: improve my music listening experience A LOT!

Already have my first post for the DIY / subwoofer forum ready 😎

I have a pair of these beautiful 2" Ceramic drivers. I mounted one of them in a box, tested it and used it gently for a couple of days. It did not fit the design so now I'm selling them as I don't have any project to put them in and I'm getting rid of some stuff. The driver measured spot on to the advertised specs and sounded great when I briefly listened to music through it (with an active crossover slope of 24db an octave at 800HZ). So you would be getting a brand new pair. I also have the square cell adapters for them, but those were never used. I will throw them in.
https://www.madisoundspeakerstore.c...cuton-cell-c51-6-286-2-ceramic-dome-midrange/
https://www.madisoundspeakerstore.com/midrange/accuton-square-cell-adapter-for-c51/

I'm pricing the pair at $1,200 (plus shipping) but I am more than willing to consider trades for woofers, mid ranges or tweeters so please feel free to ask if you have something around. I tend to use Scanspeak and Purifi stuff.
I am located in Southern California near Temecula
Cheers!

Looking for blue heat shrink if anyone has some to spare. I messed up my Mouser order this week.

3/16 in blue.

If you have something, please PM me. I'll cover postage and pay for a few inches. Located in USA.

Thanks

Hi!
I'm trying to find out what is wrong with this amplifier. It works fine for some 15minutes, then I can randomly hear some sharp "pops" from right channel. This popping sound is getting louder and louder and finally right channel gets hot and there is lots of DC at output. It burned one of my test speakers. I resoldered the amp board and changed 4 zener diodes (16volts and 39volts). Did not cure the problem - and now im using dc blocking caps at output to prevent any speaker damages.

Anyone familiar with Levinsons and such a problems?

Best regards.

Hello every one, I just joined. Thank you very much for approval or joining member here. I'm just started built and upgrade my tube amplifiers. I look forward to future interesting items in here. Thank you again for everyone and Happy holidays!🙂

Hello, i designed and built this +/-90v smps that supplies a class D irs2092s amp. The smps not only has an isolated +/-90v output, but also an isolated +5v output thats supplies a bluetooth module, connected to the irs2092s amp audio input.

I am having startup issues, that i hope someone can see the issue or solution to, that i will explain:

If i turn the bluetooth module on with an external supply, connect to it with phone, wait a few seconds and then turn the smps+amp on, everything is fine and plays nicely.

If i connect the bluetooth module to the smps +5v, and turn on mains power to smps, the irs2092s amp starts up but makes terrible noise on the speaker output, gets hot, and draws loads of current…? Sometimes the module even breaks.

The only way i have got the system to work at the moment is by having the bluetooth module already on and connected to a device. Im not sure why.

I need to design some sort of staggered startup system, this js my idea but im not sure if it would work:

I could use an rc timer that runs on the 5v, which turns on two relays after ~10 seconds which lets the +/-90v flow to the irs2092s.
This way, the bluetooth module is already on before the irs2092s.
Would it be safe to suddenly relay the irs2092s with +/-90v? I assume the modules onboard capacitors would charge up very quickly.

WiiM Pro Ultra room EQ for my workshop. I turned the sub bass off for this. Dogs weren’t happy and legged it out of there when it played the tones. Maybe I had the volume too high ha ha (this for the B&W 703s). There’s a big refinance peak in the room at 150-200 Hz which is really excited at high volumes - the room is a bit small for the 703s - the KEF LS50s are better I think with the sub bass. I’ll have to try those later.

As requested the 1et400s buffer for the 1et7040sa.







With below the gerberfiles.

Hopefully a quick question.

Regarding the “distortion adjuster” (for want of a better term), P3, on the front end board of BA3.

Is the absolute value of this pot critical? I forgot to order some 100r trimmers (as per the schematic). I have a few 200r trimmers though. Would they work just as well?

This is the tube heater supply for a phono preamp I built many years ago, the LT1084 is bad and I would like to use LM1084. The load is 1.2A. I don't see a problem but want to make sure I didn't miss something. I am also asking as a general question as I tend to build similar power supplies.

Hi,

I'm building a gainclone amp, and I need a rotary selector to switch between sources. I have three inputs to the amp, and I bought one of these:

Rotary Switches : Rotary Switches : Maplin Electronics

I got the 4-pole 3-way one and that's fine, but will this switch do for audio?

Can you recommend something else I can use for this purpose? This is my first attempt at something like this and I'm not sure if this switch will work or not, I'd like to be sure before I solder everything up.

Thanks,

Looking to make a passive input selector for multiple RCA inputs into a single preamp input. Would like 4 input selections. I just dont understand the nomenclature enough to select a good switch on my own. If someone has a link to an acceptable switch I would appreciate it.

My pair of the large ESS AMT-1s arrived and I am seriously impressed by them! I did only some quick and dirty measurements and they are flat and very low distortion, I guess they will sound great.

I will report my progress in this thread - trying out different combinations with direct radiators, paraflex and horns and ultimately a synergy horn with them.

Dear diyer, a silly question: is it possible to insert vertical radial power resistors instead of axial ones on the emitters of the final bjts?
Like this:

Same technology certainly: wirewound. In my opinion there should be better heat dissipation, as well as better distribution on the PCB (because developed in height) . I've seen few applications with radial power resistors, I don't understand why: do they have contraindications?
Thank you for your usual availability. a good day everyone
Ros

Yes I did search the forum and found nothing related to what I need.
So after 14 years in the shed I decided that is time to put it out of its misery.
Have this CV A-1800 with a faulty channel that is due to be brought back from the dead and need a few things.
14 years ago not been able to source some parts the amp was put in storage unfortunately in this period changed computers and lost the service manual (HD failure) and couldn't recover nothing from it so now trying again.
Ordered small transistors (MPS-U10/U60 from a supplier in the Netherlands, the power transistors will be ordered from Farnel/RS/Mouser in January.
With the parts sourced I will be looking for the square quick release fuse holder caps (littelfuse) ( 1 or 2 missing have to check) This model has 3 different coloured holders, White for main fuse, Blue for DC rail fuse and Red for Speakers protection fuse, again have to check not sure which one is missing.
Anyone with a Cerwin Vega A-1800 as a parts donor or with those fuse holder(s) in their parts box ?
Sorry for the long post

I'm new here and wishing everybody has a safe and happy holidays.

Hello,
I own a Harman Kardon PM640, 2X45W amplifier that I bought it back in early 80's. It still sounds very good (bass, dynamics, very smooth but not so detailed at high frequencies) and there are many problems with the buttons, tone control switches and all those mechanical parts that they are too old and causing problems to the signal path (scratches, noise, interruptions etc).
So. I am thinking to take all of these parts out off the signal path, taking the signal from the AUX RCA input, straight forward to the volume potensiometer. All other stuff will stay of the path like input selector, RIIA, tone control, balance, subsonic filter (I never use them anyway).

I am thinking of two options:
1. First Option: Keep the existent potensiometer. At the attached amplifier diagram, the two No.1 red dots, are the points where the input signal will be connected. The potensiometer is an 8-pin associated with loudness. My question here is if the 2 connection points that indicated at the diagram, are correct.

2. Second Option: Replace the potensiometer with a new one keeping loundess out. The new one it will not connected at the PCB.
My questions here are:

• The other two red dots (No. 2) are the points where the output of the potensiometer must connected? Or I have to connect after the C 401/402 and R 401/402
• The existent pot, is linear or logarithmic?
• The new one must be linear or logarithmic?
• Will be other problems that might caused by this modification?

- Any other suggestions to improve this old amp?

Thank you in advance,
Daniel

Hello, with my two latest speakers i've built (My own ported design with Sica 5,5C1,5CP and the small Hinson cube speaker from DIYRM on facebook) I've used together with DSP amps, and I've given the speakers a big boost below the drivers Fs (and the ported sica cabinet below Fb) and like what I hear. I'm clearly trying to extract lower frequencies out of the speakers at the expense of SPL. I remember reading about subwoofers with what I think is called "b6 assisted alignment" on speakerplans some time ago and found a formula from old time trusted member djk in this thread https://forum.speakerplans.com/don-keeles-vented-box-formulas_topic41578.html

It's supposedly doing what I have been trying to do but in a more controlled manner (and with the possibility to simulate the speaker), trying to extract low frequencies out of small cabinets with a filter/EQ boost. On my neverending quest for lower bass I started looking at drivers (best with a Qts of .312) and low tuning and I found the SB15CAC30-4 which looked interesting. I simulated according to the formula (Qts^2)*Vas*4.5 = box size. Fb should be (Fs/Qts)*0.312. I think I can understand the beauty of the alignment from the simulation in hornresp, however I got what I think is the port resonance way lower than I had hoped, I wanted to make this a 2 way cabinet and hoped for the 5" driver to be able to meet up with a tweeter somewhere in the 2500-3500hz region, but the port resonance is already showing around 300 hz. Is this alignment not suited for 2 way speakers like this? Should I avoid building with the port resonance audible like this? Thanks for any assistance. I'm a noob at this so please bare with me.

I really like tweeters so I saved the best for last...
I think the tweeter is the most important part of good audio, for me they are the ones that add the final details to the sound.
It makes the sound more sculpted, so to speak.
And I couldn't help but notice and research a lot about the fact that there are several types of tweeters such as:
The silk dome tweeter, metal dome tweeter, ribbon tweeter, planar-magnetic tweeter, horn, electrostatic tweeter, super tweeter, piezoelectric tweeter and plasma tweeter.
Of these to my ear, what has the best possible quality (I know it's relative) is the silk dome... When I listen to a saxophone through this tweeter it seems so natural that it enchants the eyes.
Of all these, in your opinion, which is the best and why?
I also saw that there is a tweeter with silk edge and ceramic, I've never heard it play, does anyone know if it's even better?

Any answer, teaching or opinion is always welcome guys.
Thanks in advance.


Pedroga

Hi!
How much gain the Shishido LCR Phono capable of?

Thank you!

I'm looking for a model of a planar electrostatic speaker represented by physical components, similar to the speaker model presented in this Stereophile magazine article. Although an electrostatic speaker is often described as acting like a capacitor it is also usually quoted as having a nominal impedance, usually 4 ohms. Since a capacitor's reactance varies continuously with frequency it would not seem to have a "nominal impedance" so I'm thinking that the speaker model must be more complex than just a simple capacitor. Does anyone have a model that is a good representation of an electrostatic speaker?

I seem to remember a method of manipulating high spl woofers to extend the f3 at the expense of some sensitivity. I would like to get f3 in the 40's with my Delta Pro 12a.
Can anyone expound on this idea?

David

Hi ! i have found this very interesting video on Yotube

Login to view embedded media
my thoughts immediately went to the toroidal power transformers and the iron screws used to secure them to the chassis
Question
has anyone ever tried to secure the toroidals without using metal accessories? using nylon cable ties for example?
I've seen that there are rather thick silicone rubber mats that resist heat and should also absorb vibrations
these could be placed under the toroid
then two diametrically opposed holes and two cable ties at 180 degrees from each other and voilà
is it a load of crap? I've never seen anyone do it to be honest

I need a 120mm x 25mm 12V cooling fan. The 2 in my amp (Adcom GFA-5800) are worn out & noisy.
These are 2-wire, low-rpm & don't move a lot of cfm. Most everything I'm seeing on Amazon are the opposite.

As in "technically sound / technically sophisticated". Must include measurements, at the very least frequency response, harmonic distortion, and radiation pattern - that's the very least we need to know to judge.

I'm curious, but don't feel like browsing hundreds of pages to find out. Feel free linking to build reports that you think qualify. Maybe this thread can even turn into a nice public collection.

Hello, I have a Rockford rf2002 amplifier that has a nasty alternator whine NO MATTER which system it's attached to, and nothing solves it. I unhook it, and the whine goes away. The whine is system wide and goes away when I disconnect the amplifier. What electronic components could be faulty? A schematic would help.

Hi Folks, question about wood thickness and/or bracing for the Carmody Amiga speakers. I have built a couple pair of Overnight Sensations MTM, and really like them, and look forward to a set of the Amigas. But I have a question based on my habit of trying to repurpose old tabletops as speaker cabinets. The typical thickness is maybe 1/2", and cherry. so...not quite the recommended 3/4 MDF or such.

I would really rather not laminate up to 3/4, and instead use more bracing. Is this a bad idea, and if not, what about adding 4 additional braces (in-between existing braces), and making up the difference in volume with a slight tweak to length? I could use 3/4" ply for all the bracing.

Thanks!

I'm looking to build an EQ for a TC9 array and was hoping a PCB or kit was available to make this a bit easier. I vaguely remember it was an op amp based circuit originally used with the IDS25.

Anyone know of a source for something like this?

Is anyone aware of a project that configures an RPi5 as an audio gadget that can perform DSP and then output to USB or a directly connected DAC, where the clock is essentially driven by the output?

ie it would look like a USB DAC to upstream (say, a Wiim Ultra) and then be able to run CamillaDSP or plain ALSA filters?

Anyone have recommendations for a decent set of feet for heavy amplifiers? I have some vintage SS amps from the 1970s that are heavy and the feet have deteriorated. I would like to find decent feet and I am not finding anything I really like. I checked Amazon, Parts Express and Mouser. I don't really want those black stiff rubber feet that are 5/8 in diameter and similar height.

The feet that are on the amps now are an inch wide and probably some sort of rubber...which has now cracked and become brittle. Any info or links to examples would be appreciated.

Thanks

Hello everyone, I'm from Poland, I'm a fan of vintage hifi and ultrasonic equipment (rather near ultrasonic, not as high as eg. USG range).
I work in my own company that uses the sounds and ultrasounds of nature and the environment.

I'm modelling front-loaded stubbed horn with throat chamber and rear vent. I'm using 2x 18DS115-8 in the model.
Currently I have a 20 mm peak @ Eg=116.62V which is 3.4kW @ 4ohms. Driver's Xmax is 16.5mm.
How realistic is the calculated displacement considering the model uses pure sine wave for the calculation?
What diaphragm displacement should I accept in the model?

Hi all, i am go to build a set of these speakers, thinking to use poplar plywood 28 mm thick, any toughts on that? thanks for answer 🙂

This amp blows the rail caps,rated 100v.
Rail voltage is about75v and goes up 114v when I apply a signal.
Any suggestions?

So I have a class A/B car amplifier that I've measured with an oscilloscope to do 100 watts rms per channel with a 1khz sine wave. I also have a tda7498e chip amp that I've measured to do around 107-115 watts rms both on 4 ohm. The car amp power rails are 40v each and I'm currently running the tda7498e off 8 lipos that start at 33.5v yet the chip amp gets much louder than my class A/B with 80vpp. What gives? The class d sounds much better to me as well. I think it's time to start investigating boost converters. If I can find a converter that works I think I'll run 2 of these btl tda7498es

hi everyone，i am Crysty， an electric engineer from China.

As I've slowly turned into a grumpy old dude simplifying my life has become a much bigger priority. So I've gone from being an audiophile to some KRK studio monitors as my main speakers. I'm also a person with a lot of expensive hobbies (I just spent $1,400 on a sim racing setup) and as you know you can't have the best of everything in all of them. Anyway, happy to be here and do some lurking.

whilst fooling around while bored, I pointed a cat laser at a vinyl disk, and when I held up a piece of paper to the reflection, I could kinda see the individual grooves, but no detail. I then continued experimenting, where the farther away I saw the reflection the more pronounced the grooves got.

However I could not see the individual bumps inside the groove, so I got an idea, if I could take three lasers, two of them are focused on the angled sides of an individual groove, and one that points directly at the groove and reflects off of it to track it, with all these reflections pointed at photodiodes.

I know this has already been done, but, if I could, what would that entail? This is purely hypothetical, I know it’s not exactly simple. I have an excess of CD and DVD players about, all with lasers I could steal, but would a CD or DVD laser make it so I could actually see the grooves? The cat laser does not let me see what’s in the grooves, only the grooves themselves. Do I just need to focus the cat laser better? Or is this way out of the scope of things I can haphazardly hack together.

ZROCK3

Does anyone have a schematic for the Decware ZROCK3? I would like to build because I don't have 2 years to wait for the unit.

Hello- looking for a bunch of these for a line array project, must be the 8 ohm version shown in this link. thank you!
https://www.parts-express.com/Peerl...ull-Range-Driver-8-Ohm-264-1632?quantity=2000

Hi all,

Little off topic but related to output stages.
I would like to use aluminum nitride insulators for output transistors
What type of thermal paste is recommend for that insulators?
I aluminum nitride totally better (insulators plus grease) than Keratherm (without grease)?

Thanks,
Guy

Just assembled my first 'hifi' rig on the weekend.

(furniture solution pending)

Full disclosure - I'm not a hifi person, I don't know anything.

All I do know is about guitar amplifiers, speakers, pedals, FX, etc.

The reason I'm here is because I finally got around to procuring some hifi speakers to test/accompany this stereo tube amp I built last year.


here's one of the speakers

found on gumtree for (what i consider to be) a good deal.
i am told (& as per listing) they were built in the 1970s (by the seller’s DIY/enthusiast brother)

- cabinet dimensions:
75cm / 29.5” tall
48cm / 18.9” wide
30cm / 11.8” deep
constructed with 3/4” particle board.

- 12” drivers are Philips AD12100/W8
(yet to actually confirm, but it looks like they might be?)
the dust caps have ‘perished’ 😟
- apparently the other drivers are also philips/netherlands origin.
(looks like midrange drivers might be AD0210/AD0211, tweeters could be AD0160?)

• vinyl player is a cheap entry level (AUD$90 in 2012 i think)
• ultra budget phono preamp ($20?) - runs on 12V DC supply (opened it up the other day, it’s thru-hole, looks like it might be running either NE5532 or TL072, cant really see, there’s a steel shield heavily soldered over the top of part of the PCB)

Maybe my ears just aren’t golden enough, but to me this setup sounds shockingly good - especially considering the bandwidth-limiting guitar OTs etc.
also,

• supposedly the crossovers have never been recapped (wish me luck with opening the back panels)
• i’m an idiot and tested them with totally mismatched 12AX7s so the 2 channels had slightly different tone and gain (making it more difficult to level match) but it didn’t matter, still sounded great.

so how much does it matter about the missing dust caps on the 12” drivers?
- is it worth attempting to repair/replace them myself? (implied dustcap footprint diameter appears to be 70-72mm)

also one of the midrange drivers is a little bit squished/dented
- should i just leave it? or can this be remedied?

[I acknowledge there's queries in here that may be better posted in a specific thread/sub-forum, but I can't do that right now]

I am building a 17.5 inch lazy susan for my workbench to rotate receivers and amps more easily.

I have the wood round and have stained it.

I want to hear from others that use a lazy susan about my final setup (after attaching the susan base)

have you put a protective coating on yours ?

I am thinking of possibly getting a carpet tile to put on the susan

if you thought a coating was best, what did you use and how has it endured the placing of heavy equipment

thanks

Hi

dose anyone know where to find manuals for this amplifier ?
or if anyone know how to set bias and dc offset ?

Hi guru's,

I'm at a position where I can obtain some new and original Sanken output transistors, TO-3P.
I'm wanting them for replacing original TO-3 metal transistors in some of my Sansui amplifiers if needed.
I have successfully used 2SA1693/2SC4466 in a rebuild, they are 20mhz parts, without instability issues.

I wanted the the lowest gain parts, "O"= 50-100 hFE, to be closer to the originals but they only have high gain "Y" = 90-140 hFE.

( O= 50-100, P= 70-140, Y = 90-140)

I'm not educated well enough to fully understand the relationship of the gain when switching out these parts however I still would like to get the parts if higher gain would work as the lower would.

Tia.

Ben

Hi everyone, I'm looking for a IEC EN 62368-1 standard text, the recent seems to be 2024, but 2023 should also work. This standard seems to be the main safety standard for audio equipment these days, and unfortunately it is not freely available. Would appreciate your help.

Hi.
I have bought a pair of them.
But someone burnt tweets and put inside front plate car doom tweeter.
Speakers are 180w/300w 4-8ohm 2.5 way.
Drivers mid and bass 8ohm (5.4ohm DC)
Tweets unknown, I think they were 8 ohm as well but previous owner doesn't leave old parts unfortunately.
I contacted HECO directly and tweets are eol (end of life) I was ask them about tweeter specification but they refuse to answer.
I Google a lot and get just tiny amount of information. 1st crossover point it's 300hz 2nd 3400hz.
I bought SB acoustic tweeter 4ohm crossover point 2500hz and monacor 8ohm with similar crossover point. SB Acoustic handle 120w, monacor 100w peak (50W rms).
An now my question is. Can I use any of those tweeters?
I have attached picture of crossover schematic, I haven't measured inductors and resistors. But I will do if it's necessary.

Earlier in October and November, we posted some details of a preamp for our own Le Monstre 2024 :
www.diyaudio.com/community/threads/hiraga-le-monstre-2024.413301/post-7834924
www.diyaudio.com/community/threads/hiraga-le-monstre-2024.413301/post-7850825

Finally, Fran found some time to finish both the power amp and the preamp for listening.
www.diyaudio.com/community/threads/hiraga-le-monstre-2024.413301/post-7879347

We have now everything proven, and can publish in time before 2024 comes to an end.
For 2025, we still have some refinements for the ladder attenuator planned, as well as building and measuring with other transistor combinations.

In the meantime, happy reading.


Merry Christmas and Happy New Year,
Patrick

.

Hello,
I’ve encountered a problem while determing the ports for my cabinet. I’m not sure where exactly I should measure from and how to do it correctly. Does port represent only blue part or with green? Or only green, and blue part as a front chamber?
So far, I’ve been using ChatGPT to calculate and tune the ports for me, but I’ll admit, I’d really appreciate some feedback and opinions from professionals.

I’m attaching a file with my design for reference.

Hi there,

Sometimes I may look at a long running thread that I've previously posted in and want to find my own posting. I know I can look at my own content en-masseand scroll through , but is there a quick and easy way to find your own posts in a large thread?

Cheers

Stuey

Here I have a Crown D60. Dated 1974.

This has all original components including the electrolytic capacitors. Considering it's age it has impressive performance. DC offset is 0.001mV on both channels. THD measures 0.0027-0.0032% on both channels at 1Khz into a 8ohm load. Transformer is hum free and even the neon lamp still works. 47 watts into 8 ohm load at clipping.

I've always admired this topology from the designer Gerald Stanley of Crown. Patented class AB+B outputs run in a Class B. EF3 output stage. Quasi Comp output. Outputs only carry lower impedance, higher wattage loads. Only a very small amount of bias is running in the output transistors.

Very well made and easy to service.
I have many Crown amplifiers in my collection.

i plan to build a sub for my saloon set up. Already have a pair of three way towers with 10" woofers that goes around 40Hz deep, . I have a mint condition KENWOOD KFC-W2510 laying around, crossover and more than enough amp. I've been countless hours playing with WINISD, and researching, but i cannot decide the basics of the build. My goal is to get some extra low end from 40 Hz down. HOW LOW DO YOU THINK I CAN GO WITH THIS DRIVER? any suggestion for the tunning frequency? by the way... the kenwood in WINISD database is the W2509, but all parameters are the same... im thinking a 50l box tuned at 24Hz? after build i will apply a likwitz LPF AT 50... but all this can change, please tell me if all this sounds good or i have any big mistake . Something like this:

Asking $75 $65 shipped CONUS

Contains most if not all of the BOM

I have been thinking about diying something based on KEF coaxials for a long time... Now I noticed this discount offer and orderd two pairs.

https://www.auditorium.de/en/speakers/speakers/compact-speakers/kef-q150-bookshelf-speaker

Q150 is the cheapest coax that KEF makes, and the driver mostly lacks bass performance and power capacity. Xo circuit must be very simple. It was tested with Klippel NFS by Erin

https://www.erinsaudiocorner.com/loudspeakers/kef_q150/

Response is pretty good! Obviously there is great potential for dsp-xo and 3-way system!




Göran ("gornir" at diyaudio) has measured the R series coaxial http://www.audioexcite.com/?page_id=3614

Here Q100 with same 5,25" tested by Amir https://www.audiosciencereview.com/forum/index.php?threads/kef-q100-speaker-review.11987/
and Q350 with 6,5" https://www.audiosciencereview.com/forum/index.php?threads/kef-q350-speaker-review.13484/

Hi everyone.
I have been fooling around with a pair of ACAs and I'm not sure if I understand what is going on as I change their mode of operation.
As i understand it, in the standard mode it is a single ended amp with one output terminal at ground potential and the signal applied to the other speaker terminal. This signal varies from zero volts to some positive value but never goes negative. Since the amplifier inverts the signal, the positive speaker terminal is the one that is grounded and the negative terminal gets the signal.
Parallel mono is the same situation with both channels acting the same way while bridged mono inverts the signal to the other channel and floats the signal with no ground reference.
So far so good, but...
Doesn't this mean that in standard mode the speaker cone is always on one side of "zero"? With no signal the cone is at rest in the center of its travel range. Once a positive signal is applied to the negative terminal the cone will move backwards into its suspension. When will the cone ever move past the at rest position?
In balanced mode I think that the cone will vibrate about the zero, 'at rest' position. In SE mode, isn't all of the vibration on one side of zero? Would this apply to SE amps in general, including transformer coupled tube amps?
On my LaScalas the ACA amps sound MUCH better in balanced mode than parallel mode and I don't think that it's the extra voltage swing that is the difference.

Help! I want to understand and I'm not sure that I do.

Pete

Just a tale of woe for others to be aware of so that they don't fall into the same trap that I did.

I ordered some amplifier enclosures from QJ HIFI audio Store on aliexpress.com during the black Friday sales. They were listed with free delivery. Please see the picture below.

I ordered 1 to begin with to see if they would ship it. Then it was marked as shipped and a tracking number was provided so I assumed everything was OK. I waited until it got to my country before ordering a second one since the price was very good.

Instead of receiving the enclosures, I received absolutely nothing. In due course, the parcels were marked as delivered to somebody else in different cities. After discussions with NZ Post, they revealed that the contents of the packages were something else entirely. Not amplifier enclosures at all.

So this seller provided me with tracking information to somebody else's parcel that was also being shipped to my country. Since this happened twice with two different parcels, it was not simply a mistake made by the seller. It was intentional dishonesty.

The seller sent me a message saying that the item was shipped and everything was progressing normally. Later I received another message demanding 110 USD of additional shipping fees. I wouldn't spend another dime there, let alone provide them with another 110 USD!

I marked the items as not received and got a refund through aliexpress. But the entire experience has put me off buying anything on this site. From now on, if I do buy anything there, it'll just be stupid items like a few screws or some clamps for wires etc. Nothing substantial.

We have decided on a daybed instead of regular sofa for movie watching as we all like to cuddle up

I am working on the design now and stuck on n the working surface for the bass exciters. What is optimal? A regular slat system or slats on suspended rails? I can place 20x20mm rubber on the rails before putting the slats down. As well on slat ends

I can also mount squares of ply under the slats for the exciters. Never done anything like this so some guidance on bass exciters would be very appreciated

Ample class d power available with many types of modules on hand

Thanks and regards
Randy

Hello all. Trying to reorganise a massive project, bringing together a number of personal and semi pro projects together as the various subprojects are either interdependent or closely associated. I do most of these in step, working on a bit at a time

I have 5 years to complete the larger host projects and a fully equipped workshop and parts bin

Warning
The first 8 pages are full of very heavy going non-linear textual musings, revisions and misunderstandings. Best skip to post 156 as this is where systems are worked out and the real development work begins. I have found it impossible to convert the way my mind connects things to linear text, so the work part will mostly be pictorial with an open invitation for any aspect to be raised into a discussion

Breakdown of the subprojects

Tiny40s Subwoofer Challenge
Try to make a tiny subwoofer cab that can work down to 40hz or better with solid bass for close quarters listening. Been messing with this a bit and trying out a few things before making a full project of it

Volcanoe Bassinga Subwoofer
For my soundsystem. Trying to shrink deep low bass to small, highly transportable and adorable set of 4 cabs. Using pro-moble drivers

Volcanoe Bassinga, Marine Subwoofer
For my marine soundsytem, based on Polk Audio marine certified drivers

Volcanoe Nearfield Bass Monitor
For video and audio editing

Volcanoe Bassinga PR
Custom DIY marine grade passive radiators

Wavesinga Marine Subwoofer Driver
Custom DIY marine grade high xmax rotary motor driver

Club Sandwich
Porting boatbuilding FRP composites tech to subwoofer cab construction demo. Using digital workshop tech to eliminate messy bits. This will be used for cabs for the Volcanoes

These subprojects will be hosted on these project crafts

Bass Shelter
Mobile DJ booth. Promoting sound system hire, bass amp and guitar sales as well as new and used music shop and karaoke spot. Road transportable by trailer or carried on a 6m pontoon boat. This needs to have a self-sustaining electrical power systems for occupied use and an aux generator for letting rip. Following the local markets and events calendar

Volcano Soundsystem
Reggae, Dancehall and Reggaeton DJ plus karaoke and sound system hire. The focus here is massive bass systems and developing massive bass performance out of very small cabs. This will also feature a marine grade soundsytem and a set of marine grade 2.1 near to midfield systems

Bop
A 6m pontoon boat based on a pair of custom HDPE hulls with very narrow beams for good performance at displacement speeds. This vessel will be used as a floating music related for hire venue and family use. Built to marine survey

Tender to Bop
A Smartwave 3500 with a 30hp outboard. This vessel will dock with Bop as a central nacelle and petrol motive power. Basically a ute and lifeboat daughter craft. Built to marine survey

Bassinga
Daily use beachcat and on the water home office/nursery! An electric/human/wave powered craft that most of the subprojects will be fitted to

Bass Phoenix
A soundsystem masquerading as a beach exercise and transport machine 🙂 Built to Australian standards and marine survey. This chassis will be the basis of an etrike and water toy

I am in Hervey Bay, Qld. This is a sparsely populated area with large areas of calm water and long and empty beaches. It is also a major tourist hotspot and beach hire, markets, festivals and food truck type culture is alive and encouraged here. Noise pollution is not an issue as I will feature polite volume from the booth or tender, while nearby there is a loud Zumba joint that gets pretty loud. Some permits and are in place and some will be acquired once there are enough relevant details as the project matures

All comments and thoughts are welcome, as this more than experimental or downtime stuff. Anything that can pick out potential problems and pick apart misconceptions and fails would be amazing. I am well versed on the construction and marine side but acoustic design and electronics, I struggle

Bass shelter playlist
https://youtube.com/playlist?list=PLvXGZdJdbP2Lb-gYFxsxefvdCw0hHY3k7&si=FVas4cf5Nolw9BPg

Stuff like
https://www.madisoundspeakerstore.com/coaxial/seas-excel-c18en002/a-e0060-6.5-coaxial-each/
https://www.madisoundspeakerstore.com/coaxial/seas-excel-5-magnesium-cone-coax-c16n001/f-e0051/
https://www.madisoundspeakerstore.com/coaxial/satori-mt19cp-8-coaxial-with-papyrus-cone-8-ohm/
etc etc etc
OK many woofers in this life are not so smooth on top.These tweeters though are ragged, some with huge response holes, and dying above 10k or even less. I'm sure folks are using these and saying they sound lovely blah blah...but who would ever buy loose tweeters measuring like this?!?
What am I missing?

I'm looking to resuscitate my old Aragon 4004MkII, which had developed a substantial hum some years back. The existing rectifiers are KBPC3504DW units, and while the diodes still look superficially functional, the reverse current is wildly out of spec on several of them (according to my $15 ebay part checker), and when hooking them up to my bench supply and testing with higher voltage, they reverse conduct >100ma at less than 5 volts.

Sourcing replacements is easy enough (though I'm not sure what the "D" in the part number stood for,) but I'm thinking perhaps something better might be available, considering the years elapsed. I've read a few discussions on the topic, but it's far enough out of my expertise that I can't really assess who knows what they're talking about.

So any suggestions for something that's not too much more expensive than the replacement rectifiers (less than double the $4.20 each for original)? Or perhaps there's some established design for a similarly powerful amp that I could crib off of. I have no issues with soldering together discrete diodes to build them up.

For reference, the supply is +/- 70V, 18000uf capacitors, and the transformer windings measure .5 ohm. I'm not sure how to calculate the startup surge, but I'd have to guess 'substantial."

The following is a comparison of Intermodulation distortion (IMD) in 6-7" midbass drivers.

One of my lockdown speaker projects was to measure harmonic distortion and IMD in 14 10-12" subwoofers. See the thread here: A tale of 12" subwoofers, distortion and 15 dollars.

What I learned from this exercise is that the drivers that sounded subjectively more clear had lower IMD levels.

I thought I would continue the fun and measure a few 6-7" midbass drivers. I'm sure most people on this forum know, but IMD is similar to harmonic distortion except more than one tone is used. For my test I used tones at 40and 96hz as well as 50 and 210hz. Many years ago Paul Klipsch wrote a paper on how IMD is linked to cone excursion so I wanted to test the drivers in a situation where cone excursion is high and the IMD products are above the noise floor.

The test enclosure is a .5 cu ft (14 liter) sealed box with the bottom lip of the speaker just 2 inches above the floor. The microphone is on a stand 49"high with the base of the microphone 33" from the driver. A distance of about 1.5m from the speaker to the microphone. As I'm not measuring in an anechoic chamber my measurements are not comparable to anyone else's but comparisons can be made between the drivers I test.

The first two drivers I was able to test are the DIYSG Anarchy and the Purifi PTT6.5X04-NFA-01. As shown in the graphs the Purifi really shines in this IMD test. Yes, the anarchy is less than 1/5 the price and it does well for the money but the Anarchy seems to be affected by a lack of inductance control.
Erin's audio corner has klippel tested the purifi (XBl at 82%, Bl = 9.1mm, and for XC at 75%, Cms minimum was 6.9mm and the anarchy was klippel tested for the voice coil magazine (XBl at 82%, Bl = 8.5mm, and for XC at 75%, Cms minimum was 10mm). So a pretty close klippel result but the purifi outperforms the anarchy in all IMD and harmonic distortion tests I conducted.

For the 40 and 96hz test look for IMD products at 56,136,152,176,232
For the 50 and 210 test look for IMD products at
60,110,160,260,310,370

I will later convert the graphs into IMD percentage.
I am open to comments and recommendations of drivers that might do well in this test.

Hello, fellow forum members. Greetings from Brazil!

I'm new here, as you might've already guessed. Thanks for having me in this select audio forum, and I hope I can contribute to this fantastic knowledge base in the future.

Brief Background
I've been an electronics aficionado since I was a child and, more recently, I'm expanding my area of interest towards electroacoustics and embedded systems.

Currently graduating in mechatronics engineering, my most recent working experience was as a full-stack developer, writing and debugging code in C#, Ruby and Elixir.

Cheers!

I am selling a pair of EML 20A mesh that I'be bought in January and barely used it ( about 200 hours ). They are broken in as recommended by Emission Labs and work perfectly.
Asking $550 plus shipping from 06851.

Looking for folks experiences with 4-5” drivers used as dedicated midrange/midwoofers…..doesn’t matter if it’s a commercial speaker system or DIY effort. Purely subjective of course……since it’s covering the most important part of the frequency spectrum, to me…..that’s all that matters.

I‘ve been eyeballing this guy for use as a mid

https://www.parts-express.com/pedocs/specs/292-662--visaton-b100-spec-sheet.pdf

Helllo to all,

I had started a thread, about the Chinese DAC Board, but not much replay.

Now, I need information's about the Xmos XU208 Daughter Board.

This board is sold at Ali Express, Amazon, Ebay and more.

I cannot install this Xmos board to my computer.

I think, that board have no Firmware loaded, it is empty.

Does any one have some experience with this Xmos XU 208 board?

Any information's about Firmware and Software for this board.

I hope, somebody have some experience with this Board.

Thank you.

When reading about transmission line or back horn type designs the literature says they're very complex designs but then I read on forums people using designs like the frugal horn and people swapping and changing different drivers into the cabinets which to me seems like they're not so finely tuned to a driver and complex as I thought. What am I missing?

Hi everyone, new here.

This Monster HTS-3500 MKII has an analog voltmeter dial that does not register any voltage and is not lit while the unit is powered.

The PCB at the back of the voltmeter gets 120 Vac from the main board. Traces upstream on that 120Vac path on the main board burned up. Someone bridged them and they burned up again in a different spot. The voltmeter PCB itself showed no signs of overheating and components tested OK, so I bridged the burned traces in that 2nd spot and powered up the unit with the voltmeter PCB installed, but not the meter itself. Everything looked OK - no overheating, suggesting the meter itself is the culprit somehow.



The meter has 4 terminals: posts A and B, and leads C and D. Posts A and B connect to the movement (?), 75 ohms across them. Leads C and D are connected to two pins at the bottom of the dial face. Infinity ohms across them.





My questions:

• First and foremost, could anyone point me to schematics for this unit? I searched high and low but came up with nothing.
• On the voltmeter PCB, there is 13.7Vdc across A and B when the unit is powered. However, just 1.5V from a AA battery across A and B on the meter is enough to bury the needle. I don't want to connect this meter until I understand why the circuit is sending 13.7V into an instrument that's overdriven at 1.5V?
• Are C and D just holder pins for a lamp that has been removed?
• If so, what is the black cube-shaped component just upstream of C and D on the control board? Googling WT-EL7 did not yield any results.

Elsewhere, this unit has six always-on receptacles that are powered, and four switched receptacles that are not. That issue looks unrelated to the voltmeter though, so that's one for another day 🙂

Any thoughts and ideas would be much appreciated! Thanks in advance everyone.

Hi,

Like the title says I need to power up an early 90's amplifier power supply that has been sitting for many years. At least 5 and probably closer to 10 since it has seen line voltage. Just the bare power supply, the transistor board has been removed.

It is basically a big Toroidal transformer with rectifier and (4) large 10,000 uf / 90 volt capacitors. Output is +/- 80 volts.

I have a Variac transformer on order. Do I just start from say <10 volts AC and bump the voltage up once every hour until I reach house power of 120 volts over a period of many hours?

Thanks for your help!

So using the 5x derivative as it’s the only one Keele thinks has a practical purpose……the two outermost drivers are the main energy drivers of the system with each unit representing one 1/4 wave spacing…….would that suggest that the overall dispersion pattern would be equal to that of the diameter of the same size cone?……let’s say the 5 combined distance is 8”…….are we now talking about the same dispersion characteristics of an 8” cone or point source?………

Hello everyone
Home theater systems became very expensive in our country so I decided to build my own home theater. As I am a newbie to this I watched some videos on u tube. I ordered zk-tb21 amplifier from china. It states that it has 200 watts output power 2x50 watts speaker and 100 subwoofer. I am running it on 20volts 6 amp adapter.
Than I ordered 2 two way 6.5inch speakers having 100watts rms and 250 watts peak power each. Impedance 4 ohm each.
Also a subwoofer/woofer 10 inch 350 rms 1000 peak 4 ohm impedance.
Now the prob:
When I go above 50%volume speakers and sub starts to blast. At this level they produce a beautiful sound for small 10x10 room but above this level its like amp is over driving them. Then I connected both speakers in series and ran them on one channel and they were fine. So I added two 80 watts tweeters with each in series and small 4 inch sub with sub. Making all channels run on 8ohm impedance. Now the prob is there is more sound of tweeters then speakers and sub is still being over driven.
How can I optimize this system without adding more cost to produce a good quality sound (enough for 20x20 room)?
How can I stop speakers/sub from being overdriven or blow out? (In case any kid turns the volume knob to full)
How is a 200watt amp over driving speakers almost 4 times its power?

A christian outfit called Rock Amps out of Pomona CA apparently made a number of SS amps. Mine is from 1978 and unlabeled except for a sharpie SN inside the case and a Stonebridge Music Store Logo from Garden Grove CA. Haven't found a schematic online so I'm working on that. It uses two UA1458TC's, has treble, bass, reverb(spring tank), and a distortion knob. The distortion does very little but the circuit looks like a fuzz, maybe? The large cap on the trace side had come loose and the 20 Ohm resistor was blown. I'm starting to make a schematic to troubleshoot the lack of any significant change when turning the distortion pot. I figure the large cap coming loose whas what caused the resistor to blow, but like I say I'm just starting on this one, identifying components and following traces to get a schematic. Thanks for any input folks!!

Looking for a home for my satori MW13-8s
I have a couple tweeters ( for the mw13s satori looking for a mate ) - Satori line - the (4 Ohm 92 db) TW29 R- B , and the (93 db) TW29DN-B-8 two of each , any opinions of either combos in a 2 way ? or for that matter any speaker design.

I’ve got 2 400W DD audio 510Ds running on a crown XLS2000. 2 cube box tuned to 37hz with a 6” aero port. I can either run the 2 10s on separate channels at 8ohm each (theyre D4 coils) to give them 375W each, or run them on one bridged 4ohm mono channel for 2100W.


Would it be a good idea to just run a -3dB preamp on my DSP so that I can push roughly 1K max instead? My logic is that the 2 375W at 8ohm is peak power, so they won’t be receiving more than 300W realistically. Then setting ~1K to be my max power means I’ll actually be pushing more like their 400W RMS into them. Thoughts?

I've tried the LM317 as a current limiter, see diagram attached. I tried with a variac setting with approx. 165 VDC and a load getting exactly 100 mA without current limiting.

I used a 20 Ohm resistor and expected the current to be limited to 62.5 mA. However in real life testing the current is not limited at all, still giving 100 mA.
What could possibly go wrong with just a single 3 pin device and one resitor? I checked that the output was taken from the Adj. pin.
I just don't get why it's not working.

Regards, Gerrit

I use only one triode of the double 6f8g but what to do with the other half ? can I parallel them without troubles ?
I do not use the triode with topcap😊