So, I have very sensitive speakers. 110dB/w. The Maya has quite high gain. Is there a way to reduce gain without sacrificing sound quality?

I've been hooked on the immersed/surround sound from a set of stereo speakers since my first Carver Sonic Holography preamp back in the day, so I've been on a quest to replicate, but with a highly-refined set of components. Some people want to replicate "soundstage" as a concert, with the sound between their seated position and the speakers. I prefer to be sitting in the middle of the "stage", surrounded by the music.

To this end, I believe I've made most of the significant changes on all hardware, with exception of finding the right speaker crossover components. Please share your experience with the most forward sounding crossover components, including capacitors and inductors, so you can save me from this endless loop of buying, burning in, realizing it doesn't quite hit the mark, then repeat. Thanks in advance!

I'm moving my massive 18" Dayton UmaxII subwoofer out of the dining room hi-fi system to the downstairs home theater. I'm always moving speakers around. My previous subwoofers used two towers each with 2 x 7" and 2 x 10"PR, Now I'm spoiled by the low-end extension of the 18" umax so I've drawn up plans of new towers using 4x8" per tower (for a total of 8x8") or 2x12" per tower (for a total of 4x12") in sealed enclosures. Using the Dayton umax drivers, the 4x12" has more air displacement and SPL below 30Hz, but I won't be pushing these to max SPL. So take SPL off the table. Instead, I'm looking for listening impressions down under 30Hz. They're being matched to Triangle Acoustics or CSS 3TD-X. Both mains have hi-fi analytical presentation. X-over will be around 80 to 100Hz minimum 12dB using DSP, depending on what I hear. Since they are towers, they will be situated nearby the mains.

I just got a broken punch 60ix(pc764f), replace both power fet's and one output fet, I applied power, and it draw around 20amps and the C12 and C13 are getting very hot, what could it be the reason?

The Pro Upgrade to REW allows for multiple mic measurements at a time. But before I spend $100 for the upgrade, I want to make sure it can do what I have in mind for loudspeaker Spinorama measurements.

• An example: I can place 4 XLR microphones at 0, 45, 90, and 135 degrees. (I think the mics would actually be placed at 0, 315, 270 and 225 degrees as I rotate from zero toward 15 degrees, etc., but that is beside the point).
• I want to use the "Repeated Measurements" option in REW, where I can tell it that I will take 3 measurements with a 12 second delay between measurements while I adjust my manual turntable.

1. If I correctly set the "Add number" feature, will this work, such that REW can auto-number mic-1's measurements _0, _15, _30; mic-2's _45, _60, _75; mic-3's _90, _105. _120 and mic-4's _135, _150, _165?
2. For timing reference, I assume I can just use output 1 to input 5 as loopback?

Any help or suggestion is greatly appreciated.

Received this amp which was powering up without REM connected. I found a diode 4148 and NPN marked 24 and PNP marked HR transistors in down the REM path all failed. Replacements chosen using BC846BT/BC856BT. now the amp won't power up and the I cannot get +12vDC to pin 12/13 of the TL494.

All resistors around the area seem to be OK.

Is there a schematic available?

Hi, i am new here and i entered mainly because i need an answer about Tannoy CPA 12 dual concentrics.
I had to send them of for repair of the voice coil and now they are back i found out i lost the photo's i made of the wiring.
So i am a bit stuck. Also, there is a separate piece of glass (with wire) and two cables coming from it..............
I am lost here...... Is there anyone who knows the connections of the colord wires to the speaker????????
I really do not want to blow them up (again).... i'm such a doofus concerning electronics - sigh.
Want those nice speakers hooked up to Rodec mixer and Technics 1210. Only thing i still want is a good amp.
But i found one... from 1968. Or should i buy the 120 watt Denon...... hmmm, haven't made my mind up yet.

Anyway. Hope to read more on audio stuff.
Greetings Gilbert (Qibote is a name given to my by my Mandarin teacher - which i did not learn after all....)
Arnhem, Holland.

As above. Where do you place them?

If you for some reason want to dump the output cap, this is an idea of how to deal with it and still keep it pure SE. As I have a pair of 193U and matched IRFP240s, they are used in the sketch. It will probably be a hazzle to adjust bias for both terminals to zero over the sources. A circuit breaker that monitors any DC over the speaker terminals will surely be needed.
Off course it could be adopted to the 2024 Zenductor 2.

Hello!

I have a Noise ( sounds like pink noise ) problem with this amp after i push the low pass button, the problem doesnt occur if i press the hipass button.

The problem is present on both channels.

The amp works well without the low pass button pushed.

I have no schematics, but this is what i have done so far:

- RCA-Ground is ok, i desoldered the RCAs completely because it was hard to see if they are broken when installed, but they are fine!

- i measured RCA-Ground to main ground: i have around 1000 Ohms.

- i scoped the inputs and outputs on the NE 5332 which i marked:

after pushing the low pass button i get a negative offset of 60mV with visible noise on the outputs of the opamp i marked on top.

the Opamp marked in the center has also an offset of around -20mV but no noise if i push the low pass button.

Can somebody give me a hint what to check next?

Any help is much appreciated and thank you in advance!

EDIT: i forgot to mention that the opamp on top is new but that changed nothing.

I've made a bass amp with an eBay sourced 100W+100W Class D module, and instrument input using a MOSFET preamp based on this circuit:
http://www.muzique.com/schem/mosfet.htm

(The preamp runs on a 12v regulated supply rail via LM317).

I run this from an 18v cordless drill battery, but would like to have an option for more power at some outdoor gigs. I'm going to upgrade the power amp module to a TDA7948E based one, which has 160+160W and, more importantly, a higher max supply rail of 45v (up to 39v recommended on the module). https://www.ebay.co.uk/itm/387627463746?_skw=TDA7498E

Ideally I want a simple way to use either one, or two batteries of the same kind. I currently have a 2.1mm barrel connector input going through a diode (for reverse polarity protection) and a smoothing cap.

My idea is to add a second 2.1mm power input like this:



That way, I can run off 18v or 36v. I might add more diodes in series on the top input, as fully charged batteries can give about 20.7v each.

As far as I can tell:

• lower battery connected = 18v operation
• upper battery connected = non-operational (but safe)
• both batteries connected = 36v operation

I should probably put internal fuses in line with the sockets too, for good measure.

Comments please.

Hello,

The max input voltage for my amp is 3V. What is the best way to ensure the signal coming from the pre-amp/mixer does not breach this threshold? I have a mixer with gains built-in, along with a vue meter but I would like to actively monitor the voltage input and see a notification when it nears the max. I could connect my 4 channel oscope and set triggers, but would like a permanent solution.

Is there a device or voltage limiter I should consider? ( i'm not an audiophile so this is new to me )

Looking at maybe a Rane or DBX.

I've started an STM32 'peak voltage detector' project using ADC out of necessity, but would rather not re-invent the wheel and use a method/device which is reliable and tested.

Thank you!

Hi,

I hope to have a nice time here with you

Have a nice time 🙂

In the following video, several waterfall graphs are shown, comparing sealed and vented studio monitors. The first graph comparison begins at 0:16.

"Pro Audio Monitors" are all crap. Use these instead:
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As stated in the video, there is significant distortion, particularly below 100 Hz, in all of the vented designs, including the passive radiator system. He repeatedly says "small ported speaker" and "if they're small with a port". Well, what about the very large low tuned subwoofer (LLT) designs that became popular on AVS Forum 20 years ago? I suspect that, in a sense, these problems become much more severe due to the huge port area, lowering the first port resonance down in frequency and close to the low pass frequency. Are these time domain distortions not as severe with large vented enclosures?

After watching the short video above, I suppose that if the utmost accurate bass response is desired, sealed systems (including subwoofers) are really the only way to go? However, I would then expect THD to rise significantly for the sealed systems for the same output around Fb. So, more cone area and power would likely be the best choice?

Another thread here from a year ago didn't really show any major solutions to these issues:

So, I guess the best solution in most domestic situations is to go sealed and double up on cone area and power, etc. Thoughts and opinions?

So I got this brand new CDP-101 (box, manual, the whole booty) but it’s a UK1 release. So, it’s 220v and I’m a damn American and need 110v. This model doesn’t have the rear voltage selector. I looked at the service manual and the power board seems like an easy switch out (well maybe). Ya there is step up converters but yuk!

I have a donor CDP-101 USA, Canada, model and wonder if I can just switch out the power board from it to the UK1??

I’m no expert on electronics and have switched out parts on PCB boards but only after you guys told me exactly what to do.

What do you think?

Hi, recently joined this forum while building my first speaker. I have purchased a crossover layout, now looking to get some feedback on potential layouts to lower the risk of inductor coupling. Thanks!

Hello!

I'm looking for some advice on building four 8" roof mounted full range speakers. I want to create speakers that are stylish, compact and powerful!
They are to be used as DJ booth monitors or maybe, depending on the sound quality, in a small cafe. I'll start with these but will be adding a subwoofer later on.

Recently found 4pcs 8" drivers from Celestion RS1 mk2 and the Celestion SRC1 mk2 limiter/dsp that goes with the original speakers.
The drivers are called T4579 but I can't find much info on them other than that they are quite impressive full range drivers rated at 8 ohm with a power handling of 175W and a sensitivity of 99db. I believe they would be up for the job as booth monitors together with my full size club system.

The original SR1 enclosure for two of these drivers, is approx 30litres with two maybe 2,5" diameter ports.
Then there is the half size 15litre SR3 enclosure for one driver and this is the one closest to what I want to build.
Here's an article about the original speakers: https://www.muzines.co.uk/articles/celestion-sr1-sr3-monitor-system/459

I want my speakers to be unique so instead of a rectangular box I've been looking into creating a drop shaped enclosure.
As I've come to learn, a cylinder is the worst for diffraction, and a sphere is the best. So how do you think a drop shape would work out? Of course the inner chamber can be of a different shape than the outside of the enclosure.

The enclosure would be made out of plywood rings, glued together and then machined on a lathe where the max diameter is 36cm. This could make for a beautiful roof mounted design piece to put in the corners of the room or 2 by 2 in front of the DJ booth.

Ideally I'd like to make it a vented enclosure just like the SR3 but I'm unsure about the calculations. Volume, shape and port length.
At the moment I only have access to Mac computers so can't use WinISD or Hornresp.

Any pointers what to think about when designing this? Ideas?

For sale original drivers from Webern model. So 4 x bassmid and 2x tweeter. All units are in top condition. The crossovers are upgraded with Clarity MR on tweeter and Clarity Esa on bassmid plus all resistor jantzen superes. The coils are original from Vienna A. I build new parr enclosures and enjoy the sound for almost a year, but to many projects so ready to sold. This units bassmid are totaly the same like in Vienna Mozart Grand MK1 speakers. I think all units are made by Seas for Vienna A. The price for all 6 units and pair crossovers would be 350 euro plus shipping or best offer. Payment by Paypal.

Hello FR fan,

I've some Finked enclosure made from nice ply and wondering which Mark Audio will fit the best?
Alpair, Pluvia?
I compared Fonken vs Marken enclosure dimensions, quite note the same.

Thanks for sharing your thoughts, experience and whatever you want 🙂
Chris

Looking for a couple matched pair 10Y thoriated tungsten.

Hi all,
My Metcal has developed a fault, it worked fine for many years and then started to lose power, then wouldn't accept one tip, then indicated ground errors, then stopped heating an of the tips at all, with the display steadily showing 16W output but no heat. The basic handpiece has good continuity but i have no experience of the circuit or what to look for in the power supply. Any indications, and/or anyone with experience of a similar fault? There's some info on the web but it relates to older models without the SMPS and I don't know what other differences. All help appreciated!

I broke down... I bought this card for 250 euros. the design of the ultra-low noise power supplies and separate ground planes spurred me into action! What do the DAC pros think here... I'm not looking for the ultimate, I don't have the financial means... And I think it's still DIY, a bit qualitative all the same...🙂

This is my take on Ikoflexor's low noise measurement preamp.

I used a Vishay photovoltaic MOSFET driver (http://www.vishay.com/docs/81225/ssrvo126.pdf) in an unusual way to make a negative bias on the input JFET. This eliminates the huge capacitor in series with the 1 Ohm gain resistor. In fact there are no electrolytics in the signal path. The back to back PV arrays make a nice bipolar bias reference and you can simply flip the diodes to reverse polarity. On dual supplies this voltage can go outside both rails (when referenced to ground). R3 is selected for ~1/2 the supply at the drain off J1 at the desired drain current. Then when R2 is ~2XR3 the drain voltage will track roughly ½ the supply voltage over a wide range with no further adjustment. The MOSFET driver can be looked at as an isolated current in current out device (gain = .001). This times the 10Meg resistor gives a gain in this loop (FET drain current to gate voltage) of 10,000, or 10,000*gm if looked at as a voltage gain. For these FETs it's around 100 which gives decent enough operating point stability from FET to FET without trim.

The nominal gain is 60dB and BW from .1Hz to >200kHz. the dual op-amp arrangement has DC gain of one and acts at AC like a differential out amplifier. So the input stage finds Vcc/2 at the drain of the FET with optical feedback and the output stage sits at the same voltage.

This op-amp can be an ordinary bi-FET. An additional requirement was that the circuit could be used with 48V phantom power and make for a very simple one box set up. Of course the multi-paralleled FETs at the input would work but phantom power is limited to 10mA.

As built with one 2SK170 it came right out at 1.1nV as simulated and with these values and AD823, .1Hz to 400kHz. No comp-cap is needed at G = 1000, but it will be necessary at lower gains. Even a TL072 will work with Fmax becoming 200kHz or so. If C6 gets too large one can induce motor-boating, I’m sure there is a optimum set of low frequency time constants.


At 6mA current draw this whole circuit could be put under a 48V phantom supply with differential outputs on the two op-amps (gain will be +6dB more). This would require a larger resistance level in the feedback network.

Big advantage, 1Hz BW with no caps in the feedback network and no electrolytics needed anywhere (except bypassing).

(Pictures in Pass Forum)

BTW Ikoflexor my motherboard overheated and failed last week. I lost my entire address book, and it took me a few days to get the energy to assemble this.

I would like to realize a DC blocker; which of the two following solutions do you suggest and why?

Thanks

I have a Pilot amp from an old console. I recapped it quite a few years ago but only been using it a year or so. It sounds fine to me (76 yo ears with hearing aids). However, I'm sure I used cheap caps and I put JJ tubes in it. Are there specific places where really good caps would make a difference? Also, what tubes could I try.

A friend and I are planning to diagnose it soon. He just got an oscilloscope and signal generator. Then I think I should transfer it to a better-looking box. So, while I'm doing that, I may consider some changes.

I am looking for CSS SDX10 XBL2 or SDX12 XBL2 subwoofer drivers (one or pair) or in sealed boxes.

Totaly new in original packing. Price 100 eu including shipping to EU. Payment paypal. Price for pair.

Hi friends... I'm looking for this service manual. Anyone?

Hello everyone,

I have been listening to my uncle's set up since I was very young and yesterday I grabbed the opportunity to buy it. I'm in heaven. I have been an audio lover since forever, but this is the first time with what can be considered an excellent system. I'm in love!

The amp is a Forté Audio Model 3. I have been reading a lot and I'm usually a fan of the DIY on a lot of stuff, but my knowledge is limited. I had never heard about amp bias until yesterday and I know some components might need changing since this is a 25 year old amp.

It's not that it sounds bad, but I want to ensure that I'm getting the most out of it and that it's running in the most optimal way to guarantee durability.

Now, I'd like to ask if you could guide me towards what I should do so I can decide if it's something I could do alone or if I need to look for a tech. I have a multimeter, a soldering iron and all the tools I think I'd need minus the parts and knowledge so let's hope there is an e
"explain like I'm 5" version somewhere ahahah.

Thank you in advance!

I've worked in the audio industry for more than 10 years, this is by far the very best amplifier I have ever heard and I've heard them all.

Hi,

I was asked to design a PCB based on the original Ibanez CS505 chorus pedal.
Do anybody have any idea what the following component could be?
To me itl looks like a ceramic resonator.

Could it be so?

Thank you very much.

Hello, I just want to share my project which i would like to start. I want to build a custom plynth, put electronics into the separate box and play arround with the technics motor i acquired. Once I have something, I'll share it here to hear your suggestions and ides. See you guys.

https://www.xmos.com/application-notes/
Firmware AN02019
Bridge AN02003
SRC AN02034
ADAT AN01004
But do you need a full developer rig or can firmware be tested "easily" by exporting firmware via USB on a Amanero "clone"
By easily I mean like a ADAU14xx. Or is it more difficult like a MCU

Hello,

When I'm reading posts involving audio/music, it's common to find someone warning about the risk for some signals caring 3dB crest factor content in the low frequencies and once I got some knowledge I decided to investigate myself and I was never able to find anything close to this value. I'm opening this community request / database in order to collect and share information with mates.

Below some explanation from people that don't know much about this subject and also some guidance.

App to use (suggestion):

To edit audio file: Audacity (Free and open source available on Windows and Linux)
To calculate crest factor from audio file: GNU Octave (Free and open source available on Windows and Linux)

See attachment#1 for guidance: Crest Factor Thread.pdf

1) Find any music file witch is a good candidate to have low crest factor in the low frequency range.
2) Lets consider that this music in a PA will pass trough a DSP/Crossover going to Subwoofer channel that has Low-Pass Filter of 100Hz 24dB/oct and so apply this type of filter to your audio file.
3) Bennett Prescott, an Engineer from remarkable brand B&C said that a Sine Wave (Crest Factor of 3) takes 30s to heat the driver voice coil, so lets consider 60s (1min) of music file for this analysis. Source in the you tube video below:
4) Calculate the Crest Factor and other data using the the file in the attachment#2 Crest_Factor_Analysis.m (extract from zip)
5) Post the name of you music track, the artist, your music files (original + filtered), and your results (Crest Factor, Crest Factor dB, Peak and RMS).

Note: Narrow is the frequency range we evaluate, lower will be the Crest Factor, low frequencies (Subwoofers) are the worst cases.

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Crest Factor is the ratio between the peak and and average level from a music signal and other signals. Sine wave is one of the must dangers signals to a transducer/driver once it carries a lot of energy. Crest Factor is 1/0.707 = 1,41 or in dB 20*log10(1/0.707) = 3dB
Note: attachment#3 has an 1kHz sine wave audio file to analyse. 1kHz.ogg (extract from zip)


Crest Factor per ser don't tell all the history, amplitude is also important, from the image above you can see 3 different sine wave with different amplitudes (1.5, 1.0 and 0.5), but all will have the same Cresft Facfor of 3 if analysed individually.



If the audio signal exceed the amplitude of amplifier input it can clip the signal increasing even more the energy sent to the transducer/driver. Lower the amplitude, lower is the energy.So the M-file will also calculate the peak value to the signal and its average value, if the Crest Factor is low and amplitude is also low, it might not be a problem.

poor from buying hi-fi
20 years old under education as electronics-tech wishing to fix hifi
bedwritten with stress

Hello, I am repairing a Technics Se-A3 amp and while testing the 2sc2224 and 2sa964A transistors I realize that the hfe are lower than the minimum 180 announced on certain sites. So I wonder if these transistors are starting to be damaged or not. I'm testing them with the dca75pro, I can't really find the technical sheet, it doesn't seem to be available on the internet. I attach a photo with the measurements taken at 5ma. Sincerely

Hi,

A "Windows 10 friendly" PSUD 2.10 has been released today, the only significant change is the placement of the rectifiers.txt file. This has traditionally been installed in the Program Files area, however Windows 10 will raise a permissions error if you try and amend anything in those locations making edits impossible. Download link is Download

The file now sits in (typically!) C:\Users\my-login-name\AppData\Roaming\psud2\rectifiers.txt so it's possible to make edits as you wish.

Other changes incorporated were the changes in Beta builds 57-61 which were not on public release:

• Fixed memory leak
• New installer package, now asks if you want to overwrite rectifiers.txt
• Options | Auto table width added
• Tidied up HTML help screens
• Chart toolbar removed, didn't work well with new system and you can carry out the operations with the mouse anywayHelp pages updated to include a menu
• Edit rectifier properties now has link to "how to" for adding rectifiers
• Formatting issues with dialog boxes now fixed
• Chart handling much improved, mouse middle wheel etc.
• Legend box broken out to a different area
• Help file now contains latest changes (selectable from menu)
• Fixed problem with I(T1) on FW rectifier (only showing half cycle)

Other news #1: Work continues on PSUD3 but it's a ground up rewrite as the technology in PSUD2 is broken as designed. As a result, it's taking more time than I would have liked. On a positive note, all simulations are working and giving very accurate results so it's the user interface that now needs to be sorted out. More work will get done during the Christmas break and hopefully this will take it to a Beta early in the new year.

Other news #2: I'm also looking at the long overdue task of separating the rectifiers.txt file out into individual .rect files in XML format to make sharing and editing easier. This would be used with an analysis add-on to make it easier to add your own rectifiers. There's a possibility this would come out as a PSUD 2.11 as well as being in the new PSUD3.

That's it for now, please put any questions/feedback as a reply to the post, thanks!

Regards,
Duncan

Help needed with Re-Cap my Electrocompaniet AW250-DMB-R.

I wish to recap little eletrolytics and film capacitors.

What type or kind is best for this?

master board:
C1=470K100
C4=1NK100
C17,C18,C19,C20,C22= .22K63
sister board C603= .22K63
All these caps is S&M metal polypropylene.

All little electrolytics is Elna RE series.

I frequently shop for electronics on Mouser and Digikey for work. I probably spend at least 5 hours a week searching through those sites for various projects.

Out of curiosity I searched for some capacitors since I am about to place an order for a crossover network I have been working on .

One cap in my network is 220 uf. Very expensive unless its an electrolytic. Hopped on over to Mouser and found some WIMA caps. These are quality caps. Is there a parameter I am missing that is exclusive to audio applications? Why are we not buying caps like these WIMA?
https://www.mouser.com/ProductDetail/WIMA/DCP4G062209FD4JSC9?qs=RB4whv9F6rw8KxtVmsusdw==


Instead, if I go Parts Express and look up a 220uf cap I see this is the only choice and it costs a hefty $90. Double and then some of the WIMA caphttps://www.parts-express.com/Jantzen-0296-220.00-uF-400V-Cross-Cap-Series-Crossover-Capacitor-027-962?quantity=1


In my experience in manufacturing ring you are almost always better off buying an industrial, mass produced version of something rather than the boutique item. The mass produced are held to tighter tolerances. They are usually priced much better since they are mass produced. Sometimes the quality of parts inside are even better simply because they can buy better stuff since they have far more purchasing power.


Has anyone gone outside the mould and tried using industrial style caps? I'll bet if we crack open any commercial hifi units made to any volume the XO probably uses stuff like this instead of boutique cylindrical caps.

hi i have a nikko alpha III it is 8-16 ohm Rated buuuut i just figured out later in the nikko production they did something to make them 4 ohm compatible i know this because a guy is selling one and had some but not much useful info if anybody knows anything please announce it i´d be have happy to know more he said something about some stuff in the protectioncircuit

Hi everyone.
I recently re-calibrated my old signal generator (Farnell LFM 4).
Most things went well. I realised that there was a problem with the square signal (trim pot couldn’t go low enough for calibration - it was asking 14v p-p = meaning 4.92 rms and the minimum i could take it was 5.35 rms) but i don’t ever use square signal, so all ok.

The all important sine wave calibration went well. But I realized that there is a slight problem with the lowest scale.
The scales are from about 0.5v - about 14v, then from about 50mv- about 1.4v, the third from about 5mv - about 140mv, and the lowest from about 0.5mv - about 14mv. All p-p.
While on the 10mv scale (5mv-140mv p-p) i can go as low as 4mv p-p abd measure 1.3mv rms

But on the lowest scale of 1mv (0.5mv- 14mv p-p) the readings up to 5mv are a bit higher than the low settings of the previous scale. I accept the fact that the lowest scale may be more accurate on lower voltages and gives more accurate readings.
But even the lowest (near zero reading of that scale ) which lasts from 0mv to 4mv (maybe a meter or cable problem to detect readings in lower settings) is higher than the readings of the previous scale. The 10mv p-p scale gives initial readings of 1.3mv rms, the 1mv p-p gives initial readings of 1.6mv rms.

I have to admit that i can work with these settings. But if i could improve something easily why not?

The unit is super clean . Had never been opened (mine was the first ever attempted calibration on the unit - there were seals to prove it all over it). No switch had any obvious problem- no bad cap in sight.
So what can cause such an issue . Maybe a general “inherited” issue of the device because of construction and age of components ?
All measurements are taken with a 2 seperate banana plug cables (not a double banana plug to a ciaxial cable) from the signal generator to pl 259 on the meter.
Maybe straight coaxial to bnc - banana adapter (instead of 2 banana cables soldered on coaxial ) on the signal generator would help to reduce rf and noise?

Hello all,

I have a Lucid SSG192 High Definition Studio Sync Generator Low Jitter Audio Master Clock for sale
in excellent cosmetic and functional condition

AES and BNC sync inputs and outputs on XLR & BNC connectors

19" rack mount requiring 1 rack unit space, approx 180mm deep

Tested and working perfectly!

Ideal for synchronizing all the digital audio gear in your studio

Manufacturer's specs:
Digital Audio Output Sample Rates:
Internal Sync: 32, 42.336, 44.056, 44.1, 44.144, 45.937, 46.080, 47.952, 48, 48.048, 50, 88.2, 96, 100, and 192 kHz
Word Clock: 30 – 200 kHz
AES11: 30 – 100 kHz
Video In: 30 – 200 kHz @ 25 – 30 fps
Connectors
· Video Sync Input: 1 x BNC
· Video Sync Output: 1 x BNC
· Word Clock Sync Input: 1 x BNC
· Word Clock Sync Output: 4 x BNC
· AES11 Sync Input: 1 x XLR
(will accept AES3 audio)
· AES11 Sync Output: 2 x XLR
· 256x Superclock Output: 1 x BNC
· 1024x UltraClock Output: 1 x BNC

I'm thinking USD 240 is a fair price but open to offers. Postage at buyers expense

Thanks for looking and please check out the many other vintage audio items and components I have listed for sale!

Cheers, Ralph

Hi, I have got me a Luxman D-355.

Thinking of put the XO clock in it. Someone know the MHz of the oem clock?

Frank

Hello. Longtime lurker. Never had needed to post prior to this as I have always found answers from previous posts. Fell in love with tubes as a kid seeing the amps my Uncle built. Always been a HIFI junkie. I am a bit drawn to Klipsch speakers because of their high sensitivity and nostalgia. Restored some early K-horns with all of Bob Crites's goodies and have the parts for a pair of Klipsch Heresy II (with the "super heresy" mods) that I will be incorporating into a retro-console record player build powered by a Tubelab SSE that I built sparing no expense on quality parts. Just finishing a cherry/pau ferro wood enclosure for it and painting the transformer bell covers. When I get it up and running I will post some pics.

Thanks for everyones previous posts that have helped my journey.

Hello everyone,
Since my music listening room has now become a children’s room, I’m parting with some of my projects, which are either fully built or still unfinished.
As I’ve built some of these projects multiple times, a few of them are not housed in enclosures yet. If you're interested, please also check out my other listings.
——————————————————————————————————————————
For sale:

1 Matisse Fantasy Close / LITE NO.LS27 board

• The board has been tested for proper functionality (voltage measurement at test points) and calibrated.
• Populated with high-quality components:
  • Charity ESA caps
  • Mundorf MKP caps
  • Kiwame resistors
  • Riken carbon resistors
  • ...
• 1 transformer (Badel Elektronik) compatible with Matisse Fantasy Close / LITE NO.LS27.
• 1 board for input selection (4 channels, populated).
• 1 board for power-on delay (populated).
• 1 document – instructions and notes (self-created).

Price: €250 (+ shipping).
Location: 1070 Vienna, Austria.
The PCBs and components can be shipped or picked up in person.
Payment: Bank transfer in advance, cash, or PayPal (friends and family).

Feel free to reach out with any questions. Additional photos can be provided upon request and sharing of an email address.
If interested, please send me a private message.

Best regards,
Michael

Note: As with all private sales, no warranty or guarantee is provided. No returns or exchanges.

I am a young old men of 62 years, interested with high fidelity and in love of CamillaDSP

I'm Hal from near Winston Salem NC. I've built the VTA-70 tube amp and the PASS ACA solid state amp. I'm currently working on the F6 amp and learning quite a bit about the electronics involved.

Hello everyone, I’m a car audio installer for Best Buy. I know I know, we got a bad rep, but I try to do my best and I think I do really good work. I joined this forum to learn more tips and tricks on installs and to learn how to repair components!

On this forum, Tom Danley has given us some information on some interesting new ways to fold a horn. These new horns include the VTC Paraline, which combines two compression drivers on one horn, and the Jericho J4, which uses what he calls a 'layered combiner' to load 64 compression drivers on one horn.

Unity Paraline - YouTube

I decided to build one this week.

Once you figure out how they work, they're a lot of fun to build. They're waaaaaaaaaay easier to assemble than a Synergy horn, that's for sure. I built this one in under two hours.

The device that I built is neither a Paraline nor a layered a combiner. For the most part, it's a simplification of the Paraline. (I could build a *real* Paraline, but I didn't want to for this project, I wanted to do a 'proof of concept' first.)

As usual, my projects are completely kludgey and rushed and crude, but you get the general idea.

In the video, I think you'll notice a few things:

#1 - Although my compression driver appears to be firing through a block of wood, I have extension out to at least 18khz
#2 - Have you ever seen a horn that was less than four centimeters deep?
#3 - Have you ever seen a Unity horn that was smaller than a 8" woofer?

Hope you enjoy the vid.

Originally, a friend asked me to build this amp, so I gathered all the active components (which weren’t easy to find).
But after everything was ready, he changed his mind and decided to build a different amplifier instead.

Here’s what you’ll get:

- 1 matched quad 2SK170GR & 2SJ74GR (Idss 3.4mA).

- 1 matched quad 2SA872A-E & 2SC1775A-E (hFE matched using a DMM).

- 1 matched quad 2SB716A-D & 2SD756A-D (hFE matched using a DMM).

- 2 pairs of 2SB754 & 2SD844 (unmatched).

- A pair of PCBs, based on gerber files I got from here (post #12). Thanks to @EUVL for sharing them!

I guarantee authenticity of all the transistors listed above.

SOLD!!

PM me if interested

Thanks!

As I have now finished up the amplifier boards (STE100, SWE300) I wanted to start work on the controller system for the AVR. I have already started on the faders for volume control and plan on controlling them with a STM32 over I2C as shown in the diagram bellow. My main hurdle will most likely be the LCD or if I am ballsy enough, a proper HDMI I2S de-embedder with a switch and a DSP (Analog Devices Sharc). Just wanted some thoughts on the diagram and what you would do if you where to make something like this?

SOLD

Asking $50 including USA ground shipping, USA shipping only.

I used these two voltage regulators for maybe 100 hours in a 250v 50mA application. No issues.

They come built with the stock parts as supplied. I have the 2 1/2 inch tall sinks on the boards, so they are supposed to be good for up to 5 watts dissipation.

I won't ship it with the ratty instruction sheets in the photo, but I will send the purchaser a pdf of the manual that you can print out yourself.

Hi All,

Just finished a new stereo amp build using a 6F5P (ECL85) triode strapped with a beefed up split rail power supply and some oversized Musical Power Supplies output transformers. The amp sounds amazing. Despite taking great care in power supply design and layout there is still a minute amount of 120 cycle hum ? The left channel has a bit more hum than the right. The right is nearly dead silent. Speakers are 95db efficient.

The heaters are connected to a virtual ground using two 100R resistors that are connected to the cathode of one of the output tubes. Roughly 30 volts.

I am using a ground bus that only connects to the chassis in one place. The safety ground also connects to this point.

I'm getting about 100uv of ripple on all the B+ lines.

Swapping tubes does not change the hum.

The strange thing is that with both tubes removed I get equal audible 120 cycle hum in each channel. Still have to be very close to the speaker to hear it.

Replacing the tubes the hum nearly disappears as the tubes warm up.

All testing has been done with inputs grounded at the grid of the driver section.

Am I chasing a ghost here or should I be able to get this amp dead silent ?

Any thoughts ?

Thanks,

Joe

Hi everyone,
I have a pair of speakers made buy SD acoustics called SD 1. The 10 inch woofer on one side is "gone" ...Does any one have any info on these?
Thank you,
Eric 🙂

Hello everyone.

What tube testing equipment can I buy that will allow me to reliably test 6550s, 12ax7s and 12at7s? I need to buy some vintage tubes and people selling matched pairs are charging a boatload. I’d rather buy less expensive ones on eBay and test them. I feel if I were to get a bad tube or two it would overall be less expensive if I can test myself.

Happy Sunday to all,
Stu

Hi, I've got a crown XLS2000 (2100W 4ohm bridge or 2x 650W 4ohm channels) and I'm looking at getting a dayton mx15-22. I see a lot of people pushing insane power (one guy I saw had his 2 MX15s running on 3kW each).

So would 2100W be safe enough as long as I don't play test tones? And when doing sweeps maybe dial the amp volume back to 8-9? The box would be 5-6cu ft tuned to 21-23hz. Thanks!

Hi,

I am Don, living in the Netherlands and from the 80's.

I like to hobby with hifi and all sorts of electronics. Been tinkering with electronics since I was 7 or 8, my dad is very handy and taught me a lot.
Currently I am salvaging/repurposing a 7 channel amp module from a Onkyo NR717. I also collect 80's and 90's Hifi.

Thanks in advance for answering the stupid questions I might have 🙂
Don

I have configured camillaDSP to start automatically as a service on my rPi4 (bookworm) but it always fails to open the HDMI playback device on startup.

Looking at the logs this seems to be because the ALSA hdmi playback device it is not (yet) available. If I restart the service manually after the boot it then always succeeds.

Unsuccessful service start at boot:

2024-01-11 11:40:26.391688 DEBUG [src/alsadevice.rs:334] Available Playback devices: [("hw:Loopback,0,0", "Loopback, ... <<< no mention of vc4hdmi0 !!!
2024-01-11 11:40:26.402195 ERROR [src/bin.rs:286] Playback error: ALSA function 'snd_pcm_open' failed with error 'EINVAL: Invalid argument'

Click to expand...

Successful manual service restart a short time later:

2024-01-11 11:45:35.986926 DEBUG [src/alsadevice.rs:334] Available Playback devices: ... [("hw:vc4hdmi0,0,0", ... <<< vc4hdmi0 available
2024-01-11 11:45:35.991679 DEBUG [src/alsadevice.rs:352] Playback: supported channels, min: 2, max: 8, list: [2, 3, 4, 5, 6, 7, 8]
...
2024-01-11 11:45:35.992523 DEBUG [src/alsadevice.rs:392] Playback device "hdmi:vc4hdmi0,0" successfully opened

Click to expand...

Is there a way to make the camillaDSP service start conditional on the ALSA HDMI device enumeration (preferred) or just to add a delay by trial and error (horrible)?

At the moment my /lib/systemd/system/camilladsp.service just waits for syslog:

[Unit]
After=syslog.target

Click to expand...

Update

Funny how describing the problem focuses the mind... Immediately after posting I found out how to just delay any service start... and it all works as expected and hoped for, but I would still much prefer to avoid ad-hoc delays by using a suitable "After" rule!

If no better (e.g. "After") solution turns up, then here is how to fix it with a delay in the /lib/systemd/system/camilladsp.service:

[Service]
ExecStartPre=/bin/sleep 5

Click to expand...

I have a consistent slow clicking, low volume. that I hear through all speakers.

All used equipment except the PVR.

Kenwood Head KDC-BT645U
PRV DSP 2.8x
Alpine MRP-M350 (bass Amp) Chinese 4.5 inch subwoofer
Sony Xplod XM-SD46X Driving infinity 2 ways and separate tweets.
US Acoustic usx250 Driving rear single cone infinity
Total possible high usage voltage is roughly 50 amps per unit. I will never turn it up loud enough to
strike anywhere near that draw. 60 amp has been feeding fine for testing purposes.
The system will be used mostly via Bus main Batteries and alternators when driving,
which is a completely separate power path from the 48v to 12v/

I was looking to add a noise filter after the 48v to 12v converter.

Suggestions please.

Hi. I'm starting this thread to present my own version of the Blue Hawaii Tube headphone amp. I'll post schematics, pcb layout and pictures. Feel free to comment on my schematics if I did obvious errors. The Power supply is completed, and tested ok. I'll proceed with the amp pcb design in the next few weeks. Thanks for reading.

Here my own version of the power supply. It has to fit into a recycled enclosure that I had in stock, hence the custom pcb design.

The supply supports 115/230V main voltage selection. Has provision for the remote HV power transformer in/out leads, and the main 12 pins supply outputs connectors. It will connect to an AMP circular connector on the back.

Both end of the umbilical cable will use different connector pins pattern so it wont, be able to mix up the in and out. Also the 12 pins main pcb connector includes a 2 pins interlock that will be terminated into the main preamp enclosure. So the HV supply won't turn on unless the power supply and the preamp are actually connected. A small 2 pins jumper on the supply can be used to complete the interlock to test the supply.

The supply is more or less following the original published schematic. I modified the HV regulators to use IXYS 10M90S CCS chip instead of the original led/2SA1968 transistor (no longer in production) CCS to polarize the zener volt reference.
I was limited in space and I had to relocate the +/-15V regulators and the HV turn-on timer on a separate pcb that sits on top of the heater voltage transformer. The +/115 and the heater supplies turn on immediately, then after approx. 45 sec, the HV is turn on. Both +/-400V supplies are protected by fuses. Over rated resistors, zener diodes and heatsinks are used for the HV.

The 6.3Vac heater supply is referenced to the -400V supply to prevent exceeding the EL34 maximum Vh-k max of 100V. The Cathde will sit at around -350V, the the maximum Vh-k won't be exceeded.

Finally received the HV transformer and completed the assembly. It is a nice fit, but there probably not a cubic cm of space left 😉
Here a picture of my supply pcb, schematic, PCB and final assembly

According to someone who understands LM3886 circuit diagrams, do you think this design is good? Is it worth doing? I wish everyone a healthy day.

first various diyaudio topics arround Thule Audio and their circuit topologies
http://www.diyaudio.com/forums/soli...ss-b-thule-audio-topology-also-used-teac.html
http://www.diyaudio.com/forums/soli...-integrated-amplifier-rc-who-can-explain.html
http://www.diyaudio.com/forums/soli...nt-limiter-their-amplifiers-very-special.html
http://www.diyaudio.com/forums/solid-state/126352-what-happen-thule-audio.html

the first both amplifiers I know are the models "IA-120" and "IA-70". Photos are to find about
http://www.diyaudio.com/forums/soli...-amplifier-ia-120-ia120-schematic-wanted.html

In the attachement various different logos from Thule Audio

I have two Coleman Filament Regulators (V9). They both worked fine for a while, but one just died for no apparent reason. The raw-DC supply is fine, but the output voltage remains zero. For debugging it would be useful to have a circuit schematic, but I couldn't find one. Would be great if someone could help.

[ Pinging @Rod Coleman ]

I want to attach a plinth to my Seas Thor speakers in original Madisound-supplied cabinets. See pic. My plan is to use 3/4" mahogany lumber extending slightly past the edges of the Thors. See pic of JMLab speakers for the general idea. Figured I'd attach with six, or even eight, screws into the veneered MDF. Do builders feel I need to use threaded inserts (EZ-Lok style) or could I just screw straight into the MDF? Seems to me that would likely be secure enough; but would love to hear from those more experienced. Thanks.

Hello all, I have a nice Proton integrated amp that I had a question about. It has a revolving door that I got operation by changing the belt. The only thing now is that it won’t shut off when reaching its end stop. The schematic shows limit switches and I was wondering if anyone had worked on anything like it.
Worth a try.
I think this thing went bad early, looks like new.

Thanks, Rick

Hey everyone. I posted a few days earlier about looking for a fullrange project for my small room. I have since made a lot of progress in my research and my other thread is now deleted.

I have settled for a pair of SB20FRPC30-8s after reading everything I could find about them. Love the look, and they seem like amazing performers for their price.

I'm trying to familiarize myself with enclosure design, but it's going slow since I have zero point of reference, apart from indulging in many of the forum's threads. So I was hoping someone could chime in and push me in the right direction.

Here is a plan of my room with hypothetical speaker placement and listening area.

The (hypothetical) speaker placement is represented by the two, toed in red rectangles. As you can see, they would need to be placed fairly close to a wall, I guess that's something that should influence the design I end up picking.

Here are a few pointers as to what I want:

• Cabinet size is not an issue, I can go pretty big.
• I would like to milk as much bass capabilities out of these drivers as possible.
• I listen to a lot of electronic music. Deep house, ambient, techno, and some more acoustic genres. So I'm looking for the lowest possible extension. I guess my room will play its part in that search?
• I will almost always listen to them at nearfield levels, sometimes a little more, but I'm not necessarily looking at concert level playback. Just enough to fill my room with sound.
• I intend to buy a UMIK-1 to measure the speakers and correct my room through EQ once they're built
• I like the Betsy-K design a lot aesthetically. I would prefer the speaker to be wide rather than deep, if that's feasable at all.
• I will build stands to prop them up to a good height.

Any advices welcome, thanks!

I have swapped the speakers around and it still persists in the right speaker.

Advice/guidance on reusing the power supply & power amp module from the Onkyo TX-875

I've Finally decided to start stripping the rest of my old Onkyo TX-875 that's been sat in the shed partly dismantled for ages for any reusable parts however the only issue was the common HDMI fault and i did try getting it to work with I2s digital input however could never get it to work as a system, i learned a lot from experimenting with the digital DAC board from the unit with a Cubietruck SBC providing 4 stereo I2s input's however once it was put into the amplifier the system processor would mute all audio and what ever else that stopped the audio signal getting from the DAC to the power amp,

anyway upon starting to take it apart i noticed the complete power supply and power amplifier is one complete unit and for what i can tell quickly looking over the power supply and power amp board's and also looking at the service manual it should't be to difficult reuse as a complete unit

there's a couple of relay's to control the power, both main's to the primary and a couple from the secondaries to the power amplifier for B+ and B- also
Relay's for each each speaker output plus 15V+/- regulation on another board and then 7 line level input's and everything look's pretty easy to understand and modify into a 7 channel power amp to use with another pre amp the only thing holding me back is my lack of understanding of the protection circuits as there's fan control with sensor's on the heatsink's to work out but more importantly there's a Protect line coming from some transistor's fed from the IPRO and VPRO line's also another called VOLH from the power amp,
Question 1,
am i correct in thinking two of them is for over current and another over voltage sensing ?
dose one of them detect DC on the amplifiers output
Question 2,
how can i best reuse these signal's and use them to continue to help protect any speaker's connected as they appear to go straight to the processor unit and will have to test everything with the multimeter to check the voltages involved ??

any advice would be gratefully received as there's nothing wrong with the power supply and the main amplifier stage and it's a beast i would like to be able to make use of in my future project's and there's only my lack of understanding of the 3 IPRO, VPRO & VOLH control line's really stopping me so any guidance at all would be gratefully received,

thank you

Hello, i'm Pavel from Czechia, i'm music lover, vinyl freak And now beginner in Transmission line speaker building.

Hello,

any experiences with the different kind of Playstations (1 and One) as a dedicated CDP?

It seems that some real hardcore hi-enders are using them in replacement for some real expensive CDPs.

Any suggestions for tweaking and modding in order to get a great CDP?

Thanx

Thinking of future projects (active multiways of various size from very big to very small) -

What are the alternatives to the Hypex Fusion plate amps as a product? Amps and crossover functionality as a minimum.

Hypex functionality is very comprehensive:

• good amps, with limiters and protection, bridgeable, good range of models
• DSP crossovers, EQ, FIR, delay
• volume control, gain trims
• multiple inputs
• IR remote control (codes published), display
• master/slave, 3 preset configs, volume presets, input lock etc.
• Signal sensing power
• HFD software
• All in package incl power supply

Still, there must be similar products, even if not as feature-full.

I am aware of a few subwoofer plate amp products and crossover DSP products like MiniDSP but nothing that includes both multiway amps and crossovers.

Hello Forum. I've followed and learned an incredible amount here. I am continually astounded by the diversity and level of expertise here. The internet at its best. Mostly coming from a guitar amp background, but enjoy the endless opportunities to rabbit hole here.

Hello friends, Im Bob, 32 years old. Basically i repair car amplifiers from last 15 years. I want to make a car amplifier around 1200-1500 watts . Hope will get help from all of you

Looking for some well known or vetted plans for a 8+1 build to end my diy venture . I have been hunting the internet for a month now for "known brand" speakers and 8+1 are astronomically insane for pricing. I tired looking for ones that used the 10 stupid RS225-4 sitting in my basement going to waste, but seems that woofer is a pile to 2way without a gold mine XO.

I did see the Suzie-Q, but $63 just for the digital plans is absolutely stupid IMO-

Looking for something that wont be a little baby being able to be tuned to 40hz, I absolutely loath having to have subs on for music and having to turn everything on for music.

This will replace my garbage speakers in my theater- and end my speaker obsession hopefully until im rich or have not as many kids at home lol which at this rate wont be until im 80

Hi,

I´m music maker and reggae sound system owner. I love building diy speakers, audio gear and talk technical stuff about electronics, music technology etc.

Hi there!
I am trying to find a switch with an attached cable that allows me to choose between coax and Toslink without having to open the case of my lampucera. Does anyone know what I should search for? It's purpose is that I don't need to change the position of the jumper. Thanks a lot!

Hi guys, after several years of lurking on this site i decided to register to actively partecipate the community, i build sound systems for a living and i'm based in italy.
you can look for 180bpm.audio on IG to see my creations 🙂

HI, I am Karl from Malaysia. I am an Electronics Engineer and 75 years old. I have been a member since 2010, but have not been active in this Forum.
I need some help in some repair that I am currently doing. I have a IBANEZ PF60SECE-TBL acoustic guitar with a built in preamp and Equalizer. Does anyone have a Schematic for the preamp?

Hello everyone,

I am getting into tubes, I am in the process of building a 300B based on a PCB (wich will be easy)
In the meanwhile, waiting for all my coponents to arrive, I baught a LAOCHEN EL34 amp for testing.
It is based on this diagram



The thing is that the sound is really too harsch. I tried tube rolling (tung sol EL34+6SN7GT, PSVANE 5U4G), changing 2 coupling caps with mundorf but I think the schematic is just not good.

Nos I have thransformers and valves on my hands. I thought about rewireing the whole thing but I can't find any schematic usung these 3 types of tubes.

Can anyone direct me in the right direction and provide me a good diagram?
the input transformer is 320V.