Hi, fellows,
This might be a long shot but I'm asking if there is someone close to Nürnberg, Germany (Fürth to be exact) who could pick up a package containing speaker drivers and crossover components and ship it to Finland because the seller is not willing to ship. I would pay you for this service of course.

Thanks

Looking for a new pair of BMS 18N862-8 woofers.
If they’re used still let me know the condition.

Thank you

Hello everybody.
Amplifier SANSUI AU 919.
Protect mode,red led flashing.
I want to replace all "black flag"capacitors.
But for begining help me please with protect.
I was tested power supply.
+56v -56v....ok
+55v -55v...ok
+40v -40v.....ok
I desoldered and tested on protect pcb SR601 ...OK.

But the BIAS on both channels is 0mV.
Impossible to adjust.
Where I need control please.

Need help

SM

https://elektrotanya.com/sansui_au-919_sm.pdf/download.html

Hello,

I have for sale my Salas Ultra BIB V1.3.

The pcbs were drawn by Eric06(from the ugs muse group buy) and assembled by me.

Each pcb hosts a positive and a negative shunt regulator
The ccs is set for 260ma, I powered them up with 35v and set for 28v on the output.
They worked like this a year in my ugs preamp.

I sell them because I drawn the same design on an aluminum pcb, fully smd, which I can connect thermally directly to the enclosure, saving on the heatsinks.

Sold

So I have an old Harmony 430 (Valco built, same as the Gretsh 6162, Supro Royal Reverb) that uses a pair of 6973's for its power tubes. Since these tubes are becoming much harder to find (I've read that the new production EHX version sound nothing like real 6973's), I've been toying with the idea of converting it to run EL84's.

The problem is that I LOVE the sound of 6973's, and I don't want my Harmony to change in sound THAT much.

Does anyone have any insight to potential tweaks that can be made that would keep the overall sound similar should it run EL84's?

I've attached a schematic for reference.

This is the 2 ohm version of this amp .

Anyone know what U15 and D13 are ?

Hi, I want to get into DIY speaker building as I am very interested in the engineering aspect of speakers. However before a start a build I need to make some changes to the rest of the system and I would like some guidance on this. What I lack in my system today is a Spotify Connect streamer and a sub out and the ability to high pass the mains. Today my system contains of a Schiit Modi 3+ DAC, NAD C372 and Zaph Waveguide TMM speakers I built 10 years ago. I want to rebuild them to bookshelfs, or start over with new drivers, and eventually add a subwoofer with DSP.

I want to keep the cost down since I am a student so used market or even some DIY could be options. Im thinking of adding a Raspberry PI streamer with optical out, and then a miniDSP 2x4 HD as a DSP and preamp with a remote, and then use the power amp section of the NAD to the mains. This would allow for sub integration and the NAD would provide plenty of power. I am not sure this would work as intended tho so I would like to hear your opinions on this. Selling my amp and DAC and start over could of course also be an options. If you have any thoughts on this please let me know.

Hello everyone, if you have a little bit of time come take a look at this amp I recently build ( only in simulation so far ) and maybe tell me your toughts, improvements , what you think.

Also attached the .asc, if someone wants to simulate it, also for THD , im not sure I did it correctly.
BD135-136 are gonna be 140/139 in reality.

Hi. My notebook adapter is working but once my wife put it in the wall socket ,it caused spark and it turned off the main fuse at home. Last night i put it to another wall 3 way socket and it caused big spark and it turned off the main fuse in apartments electric room which was closed and its keys were at site administrators office.I could get the key and turned on the fuse. Why it happens? Does my adapter have issues? Because the adapter is very expensive here (about 40usd ) Is it good idea to connect serial inrush current limiter ( like SCK10103LIY501 10R 10mm 3A or SCK205R0MSBY 5R 20mm 7,5A. I do not know how many amperes is enough, i think 3A may be enough but not sure ) Thanks

Round 1 of the war of the monster 10" Midbasses -

On Axis FR and Harmonic Distortion.


Ciare NDH 10-3's
vs
Faital Pro 10FH520's
vs
Faital Pro 10FH530's
vs
Faital Pro 10HP1020's
vs
Eighteen Sound 10NW750's

(plus in the future: vs B&C 10PLB76's vs Beyma 10MC700ND's vs Eighteen Sound 10NDA610's).

The theme here is minimum 3" voice coils, minimum 400W RMS/AES power handling, most with flux demodulating rings, ~4-6mm Xmax. This is Texas, go big or go home (except for pricing, lol, looking to stay under $300 per driver limit). Hoping for good low-distortion performance. Intended frequency range use is about 150-200Hz on the low-end, and 1.0-1.5kHz on the top end.




































Individual Drivers - On-Axis Frequency Response - 2.83V, 1 meter, in-room, including reflections


Ciare NDH 10-3's




Faital Pro 10FH520's



Faital Pro 10FH530's



Faital Pro 10HP1020's



Eighteen Sound 10NW750's




All Drivers FR superimposed.



As expected from the FR graphs, the 10HP1020 is the "dullest" and the NDH10-3 is the "brightest" sounding. The funny thing is, all the Faital's and the 18 Sound drivers have demodulating rings in the motors, and Ciare says that the NDH10-3 does not have any kind of shorting/demodulating rings in the motor!.




Individual driver distortion performances. SPL levels at the specified 105-107 dB are @ 1m on-axis taken at ~500Hz.

Ciare NDH10-3






Faital Pro 10FH530





Faital Pro 10FH520

Faital Pro 10HP1020

Eighteen Sound 10NW750

An externally hosted image should be here but it was not working when we last tested it.

This last graph shows the THD of the 5 above midbasses superimposed into one chart, with the very last one being windowed from 80Hz-10kHz, from 0 to 4 % THD.

Next time I'll do some CSD plots and polar response plots. Maybe with some more midbasses. I had considered the AE TD10M but @ $460 fully loaded it's too much for this hobbyist, lol. I'm trying to get a hold of a pair of PD.103NR1's as well.


Here is a ZIP file containing all data thus far.

Ten Inch Midbass Drivers.zip

What do you guys think of aluminium as a cabinet material? Interested in all kinds of views and actual experiences.

Here's an example of a cabinet that could be used for a bookshelf 2-way. It's 150mm square OD, 142mm ID, 505mm high. Volume 10.2 litres. Walls are 4mm. It resonates to F above middle C, 350hz as it is.

The walls could be damped internally, and an outer layer could be added very easily on the sides, e.g. plywood or MDF or whatever.

A top and bottom would have to be added, so I'm also interested in how that would be attached. We're talking metalwork here so solutions may vary from wood - more bolts. The speaker units would be bolted on for example. I'd expect the top and bottom to be removable.

The treble unit could be either in the cabinet or above and set back to align with the mid bass.

Views?

I think we need a new small subforum in the market place.
A PIF [ Pay It Forward] or giveaway heading

Anyone deal with this issue in parallel qw pipes seperated by an odd harmonic interval (3/1) or audibly annoyed/aware of or by it in offset driver entry transmission lines aimed at the three times one quarter harmonic resonance? (Very similar ?)

or maybe in randomly spaced parallel Bp 6/8 alignments ?

Has anyone find a way to work on the output drive circuit without have the full rail voltage?

Hi,
I'm assembling a tube phono + line preamp. Both stages are fed by the same PS which I plan to build in the same chassis (but separated by a partition and enough space).

I would like to add a switch to disable the phono pre if I'm not using it, and save tube life. The way I thought of it working was to add a 3PST switch that would cut the B+ and filament supply (AC, so both wires would be connected to the switch).

The challenge I came up with is that the B+ is around 250V and the filament supply rating of the transformer is 4A. I noticed that switches are rated for both voltage and current, so I would need a 500V, 4A 3PST switch that would make a real bulky and hard to find piece of iron.

I also saw that some switches are rated for e.g 10A / 250V or 15A / 125V, so I wonder if there is a correlation between the two, and I could run a high-voltage, low-current (B+) and two low-voltage, high-current (filament) wires through the same switch?

Is this a good idea at all to mix these paths, or am I setting myself up for a safety hazard? If it is a good idea, are my assumptions correct?

Thanks
gm

Hi everyone! For a project wich has to go loud i need a custom passive membrane. I contacted some companies but the costs are to high. Is there someone who knows wich rubber is used in those surrounds and is it possible to make a custom myself with a malt. In theory it should be possible ofcourse but i don't know the rubber "ingredients" and thus can't find it on google. There are flexible silicons but i think it's not strong enough to make a surround...

Thanks

Does anyone have in depth specs for this attenuator? Maybe a schematic and power ratings?

Something more in depth than this:
https://audio-database.com/PIONEER-EXCLUSIVE/unit/at-8s-e.html

How similar is it to the Fostex R100T2?
Thanks!

like a lot of novices I’m trying to correlate ts parameters into more “subjective” information.
I’m working on a build with these fixed parameters.
2- 12 or 15” woofer per box
250 L net volume, (could be made smaller, thinking add sand bags in less volume is helpful)
Crossover at 4-500hz to 2” compression driver,(BMS 4592)
DSP controlled, 350w @8 Ohm bass amp
Only 2 ch music, no movies, not too concerned about anything under 30-35hz.

For reasons of having DSP eq, large box volume and wanting a very articulate, “fast, tight” bass, I’m planing on sealed boxes.

Articulate and clear are the best words for what I’m looking for in this, say 30-500hz range.

The takeaways I’ve gained from reading is that box size maze a big difference, Dsp can negate “some” t/a parameters.

I’ve been looking at JBL 2216nd, Acoustic Elegance td15s, Faital 15FH520, Faital PR400. BMS 15 woofers, (5 mo wait)

Any advice on how to make a decision based on my parameters? Not necessarily a recommendation m, but a way to better evaluate choices?

Thanks for any perspective.

A bit of a long shot but anyone got a kit of parts they aren’t going to build, or even a part completed / completed SissySIT?

Hi,

I have Roland Cube 60 bass (orange, older version) on my bench.
Power amp is good, no noise, healthy.
Power supply caps are replaced with new, all voltages are correct.

Problems are located in preamp, scratchy pots and hum of around 150Hz.
Hum dissapear if I switch preamp off and use power amp only.
Hum is not Volume pot related, it is there after amp is ON.

Preamp is built around three transistors (Q1,2,3).
-voltages in preamp on Q1 (2SK117) are OK
-all 4 pots in tonestack are replaced- new -no change, no DC anywhere.
(Vol pot is especially scratchy then treble and Mid + Bass less)
-all tonestack capacitors and resistors arround Q2,Q3 are new
(Q2 is 2SK117, Q3 is 2SC2240)
-voltages on Q2+Q3 are not OK, according to schematics
(Q2: G= close to 0, D= 28,2V, S= 0,33V; Q3: B= 28,2V, E=29,6V, C=37V)
-it seems there is also problem with L1 (measured 10H and 270ohm DCR)
-Q2+3 were tested outside PCB (no shorts or leakeage)
-grounding is tested and checked a few times, all OK

There isn’t any data about L1, it is marked on the body: 5R.
It looks L1 is part of series filter with R16 (1,8k) and C8 (1uF).
L1 is tied to ground with one end.
If I ground the other leg of L1, hum dissapear, sound is a bit changed.
If I ground it at the input, hum is completely gone.

Any ideas regarding scratchy pots, L1 and voltages on Q2+3?
I don’t have spare transistor Q2+3 to try, must be ordered.
What would be value of inductor at this location for bass amp?

Thanks in advance!

Are there any drawings of 4x12' slobs out there? I want to build slob boxes that you know work.

Attaches principle sketch.

Im trying to understand the implications of the first cap on input to pre-amp.
Have purchased all the el-cheapo preamps being sold in my country.
Im comparing them to study differences.
Today is a bad day with brain fog. So apologies in advance if some of you consider this a stupid question.
The two caps in question are C1 and C2. If I remember right these are called input decoupling caps.
Their purpose is to remove any DC from the input signal right ?. As the input signal is off a MM turn table. I see no reason for any d/c being present on the line.
Long story short. All the other boards I have use a 1 UF cap for C1 and C2.
This particular board uses 10 Uf. In a lot of places where the other boards use 1Uf.
What are the implications of using a 10Uf cap vs a 1Uf cap on the input line ?. And can I / should I just by-pass it
Is there a s/w that can simulate the impact of changing this cap or a web page calculator where I can change this value and see the impact ?.

Wavetek Rockland 5830a FFT Spectrum Analyzer , .005hz to 100 Khz single channel , 0.01 hz to 50 Khz dual channel . Can do Nyquist plots , Internal Tracking generator source . Auto-Calibration feature , zero's inputs. 110 dB signal to noise ratio. Ideal for Audio work . Waterfall plots .This is an excellent analyzer . Extra chassis available for parts . Comes with both user and service manuals .
Price $550 Cdn OBO
Second complete chassis available , but needs service.


Shipping from Calgary Alberta Canada Postal Code T3C2A1
Weight is around 30 lbs
Note; Second chassis is available ,needs a new crystal in sampling card , otherwise it's all there. Best offers on it only please !

I found an old non-working Velodyne F Series Servo sub and and wonder if, after removing its internal amplifier, whether I can power the woofer in ints enclosure with an exterior sub amplifier that has both volume and crossover controls. This is the THIRD Velodyne sub that I've found and carried home to test. The speaker looks great - the speaker and amp only respond when the volume control is touched or turned - and then only for a second each time. I have yet to breach the cabinet to remove the amplifier... I assume I'll need to remove the speaker for access. AT now 71, this will be the last Velodyne I carry home!

For sale are parts for building a balanced Neurochrome preamp --
1x input buffer
1x preamp power supply
2x input selector boards
1x input selector board

The cost for new is $407+shipping for the Neurochrome parts alone,
I am asking $380 shipped including the BOM (which includes the relays, lorlin switch, IC's, terminals, LEDs etc).

Other parts I have for this project if interested:

• New/unused DIY audio store Galaxy 1U w/Aluminum Covers / 230mm x 170mm. Store price $79, asking price: $55
• Neutrik XLR connectors and Bulgin anti-vandal switch
• 2x relay based volume control units, controllable by either rotary encoder or remote control - $100

https://www.toutlehautparleur.com/media/catalog/product/datasheet/precision_devices/PDN.2450-8.pdf

is this thing good to make sub cabinets ?
horn loaded or reflex they advertise
only 1kw AES and 10mm Xmax
but they claim only 2db power compression

Any chance someone has (2) HA9P5002-5z or HA9P5002-9z Ops Amps (SOIC-8) they would sell? Trying to build the Norwood IPS for the M2x DiyA amplifier?
I have looked everywhere and actually ordered both from Win Source who said they had 10,000+ of each version. After getting confirmation of my order from Win Source I ordered all the other parts needed from Mouser - only to get an email 24 hours later advising that Win Source is sold out. Mouser and Digi-Key both say Mid to Late 2023 to get some stock. Here I am hoping that someone bought a couple extras over the past few years.

PM me and we can work out the details. Thanks.

Summoning planet10

While horn enclosure build of altec 515 is almost done to death and is huge,
I am thinking is it possible to compact the whole enclosure by using troels Dtqwt design.

So my idea is having the 288 compression drive ，mid woofer 515 , and a bass woofer (have not decide which yet）at the back. This combo should be relative compact than the traditionsl build but also compensate the lack of bass extension of 515 woofer.

however I don’t know how to estimate the relative size or whether this idea is correct

I believe the crossover section are the usual suspects, 500hz and 50hz.

I am not requesting a fish but just want to know the feasibility and is their a reduction in size.

Hello,

Quite a while ago I asked my dad for his old HK640 that we used to have at home. I remembered it having some problems and was interested in fixing it up and using it. I have made some progress, but am currently somewhat stuck. I've been working on it off and on for quite a while, so I can't remember the whole timeline 100% anymore, but I will try to sum it up as accurately as possible. (service manual is quite easy to find, for instance here)

I remember the amplifier being in use until about 10 years ago. I do not know since when, but for a few years before it being replaced, there was an issue with either one of the left/right channels, or one of the two speaker groups. I think it just did not sound right but it might have not worked at all.
Fast forward to a year ago when I got it from my dad. When I got it I think the left channel did not work at all. I opened it up and noticed C419 looked broken. I also retouched some solder points that looked particularly crappy and cleaned the pcb up a bit. After this, the left channel worked again, although it was slightly more quiet than the right channel. Did not have much time to continue working on it then, but used it for about half a year without much issue. Sometimes the left channel would get very quiet, but this was usually fixed by wiggling the balance pot a bit. A few months ago I left town for about 2 months, and when I got back the amplifier would not work at all. After some investigating, I noticed that one of the output transistors, as well as R445 were broken. I replaced all of the output transistors, as well as R447 and R445. I also cleaned all of the pots. After this, the right channel is completely fine, but the left channel is still broken. I do some testing and find that R449 is broken, and I also accidentally break the idling current adjust trimpot (woops). Replace both of these, still no left channel. I find R407 to be broken and also check most other resistors, who all seem fine. So I replace R407, still no left channel.

Currently, the status is that the right channel is fine, but there is a few volts across the left channel speaker output, while there is no voltage across TP401 and TP403 (the measure points while adjusting the idling current). I am new to audio equipment and have only done a few small repairs of other electrical equipment. However, I can solder (although not the best) and know about components and how to use a DMM. I have checked all transistors with the continuity mode of my DMM for shorts, but have not pulled them out to test them properly. I have also checked most capacitors with the resistance mode while on the pcb but have not found anything obviously faulty so far. I am afraid I am going to have to pull out all of the transistors and possibly capacitors to test them, which with my soldering skills will be a very big task, so I was hoping there might be some other things I could still try beforehand which I might be missing.

Sorry for the long messy story, I wanted to give as much info as possible. Any help would be appreciated.

I sell a pair of Mundorf Supreme Silver Gold 10uf matched pair caps. I buy this some 2 years ago for my crossovers by Hifi Collective in Uk. Caps are in verry good condition only the legs were cut and are now 3-4 cm long. This are verry big caps 110mm X 50mm, but with verry god sound. Price would be 150eu plus shipping inside EU. I pay for new over 400eu with shipping.

4 pieces, used but 100%working condition. 0,47uf value. Verry, verry good sounding pio caps.
50 euro including shipping EU.

Hi All,

I have a dead 2SA815 driver transistor in my Denon PMA 830 Power amp. I have some MJE172 and 182 that I'm hoping to use a sub or the 2SA815 and 2SA915. On paper they have good specs that exceed the original in many ways. Although they have a lower max Vce, they should be well within their limits in this circuit so I don't see a problem there. One area that is lacking in my knowledge is how different Vbeon and Vcesat specs will operate in this circuit. The MJE have about 20mV higher Vbeon and 5mV or so lower Vcesat readings on my Atlas DCA so I'm trying to determine if this will be an issue. The base voltages are pretty small in this circuit so I was concerned that a difference in those specs may make a difference.

Power amp schematic is attached

Hello.
Need help for reanimated one PIONEER SA 7800.
All 4 output transistors are dead.
I replaced all burn resistors,4 drivers q23....q26,and tested all parts on power amplifier board.Voltages +&-46v...ok+&-48v...ok
But now on output transistors I have negative voltage.
I know,Its NSA Amplifier and need very strict control,but I don't understand where is problem.

Q1. B -14.5v E. -12.9v
Q3. B. -18v. E. -13.3v
Q4. B. -9.4v E -3.7v
Q2. B. -4.3v. E. -3v
On 4 collector's +...-46v....ok

Thank you

Service manual
https://www.manualslib.com/manual/940262/Pioneer-Sa-7800.html

2 single ended B1 boards with matching JFETs from diyaudio store. all discrete design with the finest audio grade components.

Additional PCB mount holes for chassis (can be seen in the attached pictures)

asking 85$ for both + shipping charges.

thanks!

Hello friends, and i wish you and your significant others my best for Xmas.

Well, i received an original 1974 headphone, with the plus that it's non working.

I guessed someone else put their hands on it, since the coil threads are broken to the pins, and it seems I'm not able to find where the two threads start on the coil...
How can I solve this misters?

Yes i know about the lifetime guarantee etc., But i really don't know whether this works also here in Europe.

So, the question is, how do I take out two threads at the two ends of the coil?

I try to attach some pictures, hope to clarify how things are.

Thank you again and my best wishes!

I have a nice pair of Sansui floorstanding speakers here that I wish to convert from a 2-Way into a 3-Way.
The Sansui has dual 8" woofers in a tall box
I have a pair of the Hi-Vi TN28 given to me by rabbitz a while ago to top mount.
I intend to use the existing tweeter position in the top of the box to place a small midrange.
What I am looking for is a driver with an integrated can type assembly that will fit in the existing tweeter hole position,
I have a pair of Foster drivers here but they are 5.5" and too large.
Before I start mucking about with coffee cans and mounting from the rear does anybody know of an existing 100mm midrange with a can of about a litre or so that isn't your typical sealed back mid?
I don't know of any sealed back mid that sounds good crossed over as low as 400Hz, if you do I may be interested if you could post a link

Hi all!

I've been a member for a couple of years now, it occured to me i havent introduced myself yet 🙂

I dont have much electronical knowledge, but i do love thinkering alot and love to take stuff apart and improve it! Mostly i search this forum for diy solutions and upgrades.
i now own a cute little chinese tube amp, the audioromy FU29, which use the russian GU29 tubes. i've replaced most of the capacitors and did some tube rolling.

For speakers i currently own the cabasse sloop M4 speakers, with upgraded capacitors in the XO. these are 94db efficient and have a really nice balanced sound. they have a 12 inch woofer, and a sealed enclosure and the bass reproduction is extremely clean, detailed and fast. They do really well on jazz and blues recordings, not so great on modern day bass heavy music, but i will take that trade off any day of the week!

I mostly stream my music form an iFi zenstream to a nice chinese dac, the xiangsheng DAC 05B, which uses dual AKM 4495's, has a tube buffer and sounds alot better then its 500$ pricetag might suggest. i replaced the opamps with descrete opamps from korea, the audiofeel OPA 401. I also changed the voltage regulators to linear low noise ones and replaced the PS and signal capacitors, aswell as the coupling caps.

I also own a Thorens TD125 MK2 turntable, completely stock, with a hagerman bugle phonoamp.

i have made all my interconnects myself, and now am looking into the world of AC filtering and try to learn more about that 🙂

I am always looking for the next thing to improve or adjust in my system, but also try to keep it low budget, as i have some other hobbies that are expensive and time consuming, but i would to built my own DIY speakers someday.

am i normal? i have noticed for some time that i hear top octave frequencies muted when i have my speakers setup in a standard stereo triangle, but when i rearange the speakers so they stand much wider, so they are positionend more to the my sides then in front of me, then i hear the missing top octave again, is it possible to have hearing loss that is angle depentent for incomming frequencies?
for pure tonality i could stay with this very wide angle setup but the stereo phantom image suffers badly.
i have also tried with some reflectors slightly behind and above my head in listening position which gives back some air and atmospheric to the music, but maybe i need a hi end solution like a hearing aid? or do i need to re-configure my listening room?

I dont really need it, but it keeps popping up in my feeds, and it does look interesting. Anybody knows about this integrated board?

DKK 570.22 5％ Off | MA5332MS Class D Digital Power Amplifier Board/stereo Dual Channel/high Power Module 2x200w
https://a.aliexpress.com/_EIs5PHt

The whole set sells for $350, including PayPal and shipping to worldwide.

• Raspberry Pi4B 2G
  Heat sink and SD card extension board installed
• Filter capacitor board
  Function similar to ConditionerPi, you can provide 5v power supply for the whole system from this board through DC 2.1 Jack
• Ian FifoPi Q3 Ultimate
  Crystal has been upgraded to Accusilicon AS318B
• Ian ReClockPi
• Ian HDMIpi MkII
• Some extra stainless standoffs and U.FL cable

I purchased a pair of 1977's Cantatas in very good shape for a very attractive price. The set had been already recapped with a Falcon kit. With this, they sounded good but strangely dull. The highest sparkle was somehow not there. Or it was there but squashed flat. I did a simple frequency check and could hear both tweeters up to 12000 Hz (above this I think my aging ears are limiting).

The treble became a bit better after I put low loss caps into the tweeter section (WIMA MKP10 0.1uF, Mundorf polys 3.3uF and 6.8uF and Mundorf E-caps plain 4.7uF) . But in comparison to the 105.1 which I also have it is still dull. It is even dull with the +2 db setting. The highest frequencies are not really there.

I don't have measuring equipment. What could be the cause of this? Aging T52s? Both with the same aging defects? The T52s in the 105.1s are still great. Same vintage. T52s don't use ferrofluid. I will check the 2R2 resistor R5 in the naB network next time I open them up and will change the 3.3uF to an even better quality cap. But according to my experiences with lots of vintage KEF speakers the Cantatas should sound fantastic even after a recap with electrolytics.

What could be amiss? I cleaned the switches and all connectors already. I did not look a the bass crossover, as I need to take out the bass driver to access it.
Any more ideas? Thank you!

crossover schematics here:
http://www.hifiloudspeakers.info/Anatomy/Crossovers/Cantata/CantataCrossoverIndex.html

Hi, I want to build a pair of speakers for my desk ( PC ) , Size is not a factor . ( kind of on a budget )
First I found the Dayton's TCP 115 , with many people using them and then I found SB Acoustics who have great drivers ( satori , ceramic etc . )

I dont know what to chose between Dayton and SB Acoustics, these are the drivers I was looking into buying.

The Dayton's seem to roll of at about 2.7khz , and also bass not so great .
The SB Acoustic's have higher sensitivity , great bass but I dont know that dip at around 50hz and from 4khz they have a spike to around 7khz
idk take a look please. at the PDF's .

For Tweeters I'll get something not to expensive, textile or silk . Dayton or Monacor maybe.

Sigh! So many dead links.

Serious question: why are external links still allowed? I would like to understand that because some of the older threads are not very useful with all the broken links. I understand the exception where a file is simply to large to be accommodated on diyaudio. But in most cases the dead links are to jpg files of schematics that could not have been be very large.

Here is an example: https://www.diyaudio.com/community/threads/6p36s-push-pull-hifi-amp.251395/#post-3822908 BTW, does “IMGHTTPDEAD” mean and how does it get inserted?

In my view an external link to a personal webpage or data storage is unacceptable on diyaudio, because it will be a dead link in a few short years.

AKM factory fire

AKM Factory Fire—A Pro-Audio Industry Disaster | ProSoundNetwork.com

I recently picked up a dirty, but good condition NEC CD-730. It does not play discs (and the drawer is misbehaving but I think I have that sorted). It has the same KSS-150A as my Sony CDP-207ESD so I've been using that one to try and diagnose this NEC.

Upon putting a disc in, the spindle motor will spin it about the same amount as the Sony to read the track listing but [DISC] keeps flashing on the display while the laser constantly raises and lowers. The laser continues to do this after the disc stops spinning at least once more (with a faint but familiar click when it drops). On occasion the spindle motor will spin the disc backwards too, but I'm not really sure what that's about.

The laser sled seems to work okay - I've manually retracted it and when loading a disc it will return to its home position fine.

My current guess is that the laser itself is weak. Letting both the NEC and Sony load no disc with a white reflector above the laser, the Sony appears to be significantly brighter.

Would this behavior be in line with a laser that's weak and can't get a focus on the disc?

Thanks in advance!

We all know that replacement original Berilium diaphragms are pretty much unavailable and if you're lucky enough to find them the price is astronomical. But I also read about replacing original Be parts with Radian diaphragms with some success. I'm particularly interested in hearing about this procedure done to TAD-4002 drivers. Can you hear/measure much difference compared to the originals?

I have a PS Audio perfect wave II dac.
I know there's a way to alter the default input option so on power up it selects the desired input automatically.
But for the life of me I cannot remember or find how to do it.
Owners manual says nothing.
PSA website and forum says nothing.
I know it's possible, but how ?

Merrry Christmas and Happy New Year!​

Thank you for all your support in 2022...​

Hope to bring more interesting products to the DIY Community in 2023.​

Hey guys, I picked up a faulty A100 recently, a couple issues which should be fixed soon

Unfortunately as a couple resistors and zeners got incredibly hot, not only has this visually burned the board but also the solder pads have either snapped off or are peeling, I wouldn't be happy with the amp even if it were working knowing that I've had to bridge legs to nearby pads or had to solder directly to a trace after scratching off the insulation

So, as any sane and rational human being would do, I'm replicating the board 1:1 in PCB software and I am having a new board printed, minimum order is 5 boards so I'll be stuck with 4 spares

Just wanted to show you what I had done so far, I'm keeping it to the original but I am moving some components over a little bit to make the layout more symmetrical and visually pleasing, I'm also straightening up the trace tracks as I do prefer the look of right angle traces

I'm hoping to get this done within a week, so far I have physically measured the board and all the holes so that I have a solid base to work on and I've laid out the preamp

If anyone has any recommendations for mods and upgrades that are within my technical knowledge then please let me know!
I'm sure there's been advancements in audio components over the years which come with a different footprint/leg spacings, so if there are any go to upgrades of components then please let me know as I can incorporate the footprint of the components directly into the amplifier for native support

I'll have the boards printed in matte black to give it that premium look 😉

Which would not, strictly speaking, be a Nostromo. I like my two small Nostromos very much, but I am considering building a third for use as a center channel which will need to be close to the back wall. Can you build one with the same port on the front or is some modification of the port specs or its location needed to make this match well with the true Nostromos? I suppose, a sealed box with the same external dimensions as the small Nostromo might be a good way out, as this system will have three subwoofers (all mono signal). No need to get the lowest 20-35 hz out of the center channel.

I'll read your responses with gratitude.

Skip

Hey guys, I've just purchased a Musical Fidelity A1 from eBay on a whim and I'd like to order some parts whilst it's in the post

I've looked around the internet and either haven't found much, or I've found contradicting statements, I was wondering if anyone could tell me what they'd recommend me replacing?

I'd like to replace the power capacitors but cannot decide what specifications to use, I do a lot of soldering but this is my first amplifier referb so I don't want to buy any incorrect parts!

So I suppose my questions are:
•What capacitors should I replace and what spec capacitors should I install in place of them
•Are there any upgrades I should make whilst I am inside the amp


I have placed an order for a 47nf 250v Polyester capacitor for the AC in and some 10A10 Rectifier Diodes to replace the stock ones, hoping they are all fine and correct!

I am experimenting to transform the single front-end into push pull. I came upon this type of circuit. Note that the power mosfets can be VAS stage. The lower current of the Rush is inverted by current mirror subtracting a fixed CCS which adjusts the bias current 1.48A. As the same current of the rush subtracts itself , the distortion goes very low 0.0002% @1khz 1W , in worst case 0.09% @10khz 40W. The power mosfets work in square law bias they are thermally stabilized by LM334 mounted upon . This circuit is designed in less than an hour, To morrow , I 'll post with Single Floating Supply to take care of the offset.
Hayk

SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD SOLD

a pair of brand new Faital 15PR400 drivers. Very nice high efficiency and light weight drivers , good alternative to Altec or Acoustic Elegance

asking $450 for the pair , split shipping and PP

Is there anyway to rest these ic’s without power ?

I’m working on an amp and these are the gate driver ic’s for the outputs .

Once the driver board is put back in the amp there is no way to get to the pins on them

Hello,
Pair of 6n30p-dr super new old stock tubes from 1986.
Will be very good packed.
Asking 400 USD for a pair.
Bulk quantity is available.
Payment by PayPal, bank wire transfer or crypto

I had a shock today while listening some headphones I intended to give as a gift to a friend.The mids of these headphones are Godly...base just the right amount, highs indeed lower than my Bayerdynamic, but for midrange Jazz and probably all laptops following a V shaped reproduction will sound really cool if amplified a bit. Saxophone, tubas, female voices are like from another world ...and they seem to be more linear in the mids than my Bayerdynamic if they measure like the SL version presented here:
https://diyaudioheaven.wordpress.com/headphones/measurements/brands-s-se/hd420-sl/
I refoamed them and I already regret I promissed to give them away...I never realised that my DT880PRO were so clinical and rich in the highs before I listened to these 38 years old Sennheisers.I can't say they are the best there can be, but they seem to be perfect for long listening sessions.Such a relaxed sound...by the way I listened them to my completely refurbished Denon drm-700A.They're probably best for some ecc88 based amplifier...

Hi all,

I'm looking for a pair of 300b SE transformers - anyone got a set that they are looking to move on? Europe preferably just for shipping reasons.

What is the color scheme for connecting Markaudio 10 drivers?

I'm current using an APT Holman preamp, which I like. But it's the time of the year to do some window shopping. Budget is under $1000, much less like $500 is more reasonable.

I may end up keeping the Apt and doing some mods to it, please dont be offernded if i dont actually purchase anything - your thoughts on a replacement are appreciated.

DIY, used OK of course. But if DIY, I'd need to be able to purchase a good looking chassis since my mechanical skills are near zero.

Nice to have but NOT necesary:
Tubes - never really had a tube amp, wouldn't mind trying
Remote volume
quality phono stage
tape loops
many inputs (I only need maybe 3, depends if it has built in phono)

Hii im reparing deafbounce aab 4900.1 amplifier i have repaired it's ps and output section but clipping light is fully on with blue light i have checked all output Ic's pwn ic, driving ics with its buffer ics all are ok. Can someone help me please

Why do designers of crossovers ignore this? OK, I can understand it's a crossover.
But then builders using these on real world boxes need an extra stage to compensate for this. Why do they choose to ignore this after they have gone to the trouble of multi-amps?

Who offers a ready built PCB that can add this?

Condition:
Open box
“New, never used.”
One pair Lowther DX3 full range drivers.

New in box, one has been opened, never used.

Accept PayPal only

$10 insured shipping
PRICE TOTAL FOR ITEMS AND SHIPPING:600$

NEXO GEO S1210 2-Way Passive Loudspeaker (PAIR) (church owned) CG00N92

• Very Good condition (A few small marks and light wear. No major damage.)
• Works perfectly. No functional issues.
• ested & Approved Gear – Each piece of gear is fully tested and approved by our ChurchGear techs.
• Fast Shipping – We ship within one business day and provide you with the tracking number.
• World Wide Shipping – We ship anywhere on the planet. Please contact us for a quote.
• Easy Returns – 30-day returns for any reason, no restocking fees!*
• Giving Back – Donations are made from a portion of every purchase to aid global and local mission organizations.
• Virtual Demos – Live virtual demos are available for the item via Facetime or Skype. Please contact us for details.
• PRICE:1100$ free shipping

Hi All,

I’m probably a couple days away from a first listen on a new build so I thought I’d post some random photos so everyone can tell me all the things I did wrong that I can’t undo 😱

As per the title this is Troels’ SBA 16 MTM. My priority is midrange clarity so, after some discussion in the forums here and a quick double check with Troels I decided to go sealed and reduce the size a bit for ~.7 qtc with a -3db at 60ish hertz. Parts are from Jantzen (naturally).

I’m quite a poor carpenter so box building is typically one disaster after another. This build has been no different but I’m confident I’ll get to the finish line this weekend. I just have to make the crossover, glue in the back, make an access door for the crossover, and mount the drivers. They won’t be pretty unless I try my hands at veneering down the road. Frankly this project has been dragging on since Christmas so I have full tunnel vision on getting them hooked up in my living room regardless of what they look like. I’ll start uploading pictures in my next post.


Brian

Would it be acceptable to drive a Baxandall passive/active tone stack via a 6DJ8? I have mostly finalized a headphone amp design that is driving 6GC5 SE pentodes via a 6DJ8 (1/2) per channel, and have enough physical space and current headroom on the PSU to add another tube to the design. I've got several other 6DJ8's and Soviet 6N23P's on hand, and would like to use one to drive a tone stack in-between the preamp and power amp section, if that would be an appropriate tube to use for that. I've mainly seen high mu triodes like the 12AX7 used in that role, however. B+ here is 240v. It makes more than enough gain as is, but I'd like to keep that headroom in case I want to turn the volume up on particularly quiet tracks. Worth doing or would I be better suited to use a high mu triode?

Hi !
I apologize right away if this topic has already been debated ad nauseam
But in the world of audio reviews I see that measurements have less and less space than subjective listening
Not only that ... the few who try to find a correlation between laboratory measurements and performance are rather mistreated and the comments are even mocking
Instead, I was struck, in a positive way, by this statement that can be found in this review
https://www.stereophile.com/floorloudspeakers/99dun4/index.html
"DAL firmly believes that a full set of credible measurements, made by qualified engineering staff using state-of-the-art equipment and facilities, can reliably predict the potential of a loudspeaker to accurately reproduce the complex sounds of music."—Dunlavy Audio labs
It is known that immediately afterwards the journalist adds a lot to create some doubt and confusion
"Yet it must be said that, no matter how good the theory, how impeccable the designer's credentials, and how impressive the measurements, a speaker may still disappoint in subjective terms. The proof, as always, is in the listening"
Another interesting interview here https://www.stereophile.com/interviews/163
"John Dunlavy: Oh, no. Listening comes later. Because if you stop to think about it, no loudspeaker can sound more accurate than it measures. It may sound worse, or it may sound sweeter, prettier, but if we're talking about absolute accuracy—the ability of the speaker to reproduce as perfectly as possible whatever's fed to it—such a system can never sound more accurate than it first measures. So we try to get the greatest accuracy we can achieve from measurements. Then we begin doing what some people might call "voicing," because the best set of measurements are still open to interpretation."
I tend to believe to Mr Dunlavy
And you ?
Kind regards, gino

Looking for a couple of IMS boads for lu1014 mounting. If they have the jfets even better.

Thank you.

i live in a ural area and have limited cell coverage i have tried a couple of ideas on youtube but no help i am considering trying another one but would like to get some feed back and a better design mybe i dont have much money so i am trying to use materials i have a home one question is they use a steel clothes hanger i have a bunch of copper ground wire why not use copper for the antenna

Hey, I know there are some threads about noise problems here but I couldn't find the right answer.
I am building an amp out of an Fosi Audio ZK-502T Bluetooth 5.0 Amplifier Board (TPA3116D2 Chip).

...and I have some Issues with noise. Please hear this video for demonstration.
Login to view embedded media
For some context:
The 1 khz Sinus sound you hear is on purpose, I needed some input signal because otherwise there is a noise gate turning on. So ignore this one.
First there is this white noise like sound in the background, might be normal is not that wild. Only audible at very high volume.
But then there is also this incredible loud buzzing sound. When I touch somewhere on the circuit (ground) it gets way more silent and when I come near the cables it gets louder, even before touching.

I am connected over bluetooth, so no input device is connected.

This is the board.


I modified it a bit to build it into my casing.



I desoldered all 3 potentiometers.
The volume poti also works as an on/off switch, so I bridged these two paths to have it always on. (Red small wire)
The other connectors I wired back to the potis to have them somewhere else in the case.

Before I desoldered the potis I think there was no problem of this sort. Only tested it shortly once before so not 100% sure. My guess would be some problem with the cables or the ON/OFF shorting.

Can you please help me figure out where my problem is?
Thank you!

Hello Everyone

I got a Harman Kardon Schematic from an online source which is of a 240 - 9240 Mosfet Based amplifier.

When I tried to create a board out of it, I faced a few problems. Initially it wasn't powering/switching and I found I chose the wrong preset of 1k. I changed to same per schema, now it is giving 51 volt AC output.u

Can you please look at the schematic and let me know what's wrong with it? Also, what could be the best corrections/modifications required in this schematic so that it can operate smoothly with good results?

Thanks in advance.

Hi.

I received a pair of these speakers at a belated birthday present over the weekend. My friend thought it would be an interesting project for making some improvements on.

Unfortunately, my web searches didn't produce much useful information. One post on the World Designs forum mention a simple crossover of a 3.3uF capacitor and a 2R7 resistor. On opening the back of my units, I have 3.7uF of capacitance and a 15R resistor (plus an, as yet, unidentified component buried in hot glue).

My first change is to replace the internal wiring which is pitifully thin. It seems an odd choice, given that they spent some extra pennies on film caps instead of electrolytics.

Does anyone have any information regarding this speaker please? An owner's manual perhaps?

How about a collection of hacks and rules of thumb for audio.
It could be a simple chart showing you what range of volume your sealed speaker should use based on speaker size. You can do the complex math. And they just for fun see if the size you came up with matches the rule of thumb chart.
It could be a hack to help you pick the best transistor from a pile of possible transistors you could use for a project.
My guru says there is nothing as perfect every ear has its own preference. So why not pick a transistor my ear likes.

Let me get the ball rolling with my idea. (It could be a brain fart). So humor me.

The number one problem today with all parts is fake or substandard parts. Or picking the right part.

So I have this pile of transistors and we need to find the one type which will sound best.
Was looking at some videos on youtube where they explain how to build an amp with one transistor. A cap and a resistor.
What if I were to build a bread board where a single transistor is replaced one after the other. Power supply used is based on where in the amp the transistor is being used.
And I play some test tunes. or music and then swap out the transistors one by one. And just listen to the music. I could also use a spectrum analyser on my phone to get an idea of freq response off each transistor.
Do you think the idea has merit or do you have a better idea to quickly pick from a pile of similar transistors. The test rig could work with a single transistor or you could make one which works with PNP / NPN pairs. Im not chasing perfection just a quick and dirty test rig. Instead of a speaker we could use an audio jack and feed the signal to a scope or the mic in of your laptop. Also if its a fake it pops on the board. Worst case taking out a resistor or cap vs taking out a complete board and many other components with it.
Im still trying to understand how to pick the best transistor from a pile. With my component tester i.e. is HFE important as in higher HFE= Better. Or a certain pf value or its speed from the datasheet.

I recently purchased a used, nice condition Musical Fidelity A308 integrated amp. It works well and sounds great. I opened the top and I did notice what looks like significant modifications of the original factory capacitors throughout the unit. Below are hi res photos. Note the banks of caps sitting on wood blocks on top of the power transformers... and there seems to be replaced silver colored caps all over the main circuit board as well. The caps are not marked with branding, also no values can be seen. Below the pics of my unit are a link to an old for sale ad of a stock unit... the pics in it are not great but one can see the black original caps...

I am curious to know, if knowledgeable people here can tell me, what these modded caps are and any other thoughts or comments you might have. I will repeat, the amp is dead quiet and sounds great.

And FWIW - here is the link to photos of the innards of what should be a stock unit:

https://www.hifi4sale.net/t73965-musical-fidelity-a308-integrated-amplifiersold

I am building the Akitika Z4 Power Amplifier kit.
It is based on LM3886 - I hope they will be in stock again.
The kit has been sitting for 6 months due to work, but now I started. I think I am somewhat 60% done.
You can read about the kit here - it comes with everything except solder 🙂
I am building the 4 ohm version. It is actually easier than I thought.

There are 3 major modules, the Power Supply Board, and tho Amplifier Boards. Here a quick status.

The manual quite clearly writes how to get started, and what bags to find stuff in.
I never thought I should write it - but the PCB is quite nice. Thick and solid.


It does seem a bit scary , but it is not that bad.... I even cannot really solder. But I found the key trick is to heat up pin a few seconds before adding solder.




Within a few hours I actually made progress.....



The board is soldered on the back....




Done.....
Next, Amp board.....



Image below of finished Amp board and power supply board. I just need to finish one more.
And install it all with power supply, and a bit more stuff.



Here it will all go....



More is coming... happy for any suggestions or questions..

I'm working on a LM3886 amplifier, and I have it working and it sounds mostly great. But when I put my ears up against the speaker, I can hear a little bit of what sounds like faint power supply noise.

I've been messing with the grounding, but I can't seem to nail it.

Right now for testing I have two RCA inputs that are isolated from the chassis (verified with a multimeter). These go to two different PCBs representing the right and left channel. These are connected by two 2-wire twisted pairs. If I don't tie these to ground within the amplifier, it doesn't sound good at all. If I tie them to ground at the power supply caps, it sounds good, but it has the faint hum with my ear up close (this is the current configuration). If I take one channel and ground it instead at the speaker gnd of the appropriate channel the hum goes away and it's totally quiet. If I do the same with the other channel though, the sound gets worse. The RCA cable source is my iPad using a mini audio connector cable that splits into RCA.

Another question is should the INPUT GND be totally separate from the SIGNAL GND/ I read the Taming the LM3886 article, and it seems the consensus is to tie the SIGNAL ground into the speaker negative terminal, but it doesn't really mention what happens to the INPUT GND.

Thanks.

I want to selling audio research what best price selling

where can you sell

Item: Audio Research Reference 6
Location: Georgio.Decatur
Item Condition: MINT.
Reason for selling: Not used after upgrade to audio research reference 9
Price: US$6100+ postage.
Payment Method: Paypal buyer portection
Extra Info:
Bought from a specialist dealer in April 2020. First owner.
Condition: like new. Only 1639 engine hours.
Age: 2 years 7 months.
It is not the SE version.
Including 6 tube dampers from EAT (Cooldamper) for € 180.00.
Including 3 fine fuses Supreme 3 from Hifi-Tuning for € 135,-.
For a surcharge with LEVAR Resonance Magnetic Absorber Leveling Feet LR7-HA (SP € 899,- for € 650,-.
New price Ref 6: € 17,900.00. The Ref 6 SE even costs €20,900.
Invoice, original packaging, all accessories available.
No replacement.

Test results :

"The Reference 6 high-level preamp is a monument of current tube technology and an enrichment of the top class. It impresses with crystal-clear, spacious and highly dynamic sound performance, which, paired with excellent precision, leaves nothing to be desired. With its typical design, it proudly shows its origins , the workmanship is flawless, as you would expect from Audio Research."

" Somehow Audio Research manages to outdo itself on every occasion – at least in the last few generations of Reference series preamplifiers. The Reference 5 SE was among the very best preamps on the market, yet the Reference 6 takes it to another level.

To qualify this, the Ref 6 is substantially more transparent than its predecessor – you really hear into the recording (as an enthusiast and reader of these pages, I'm sure you know what I mean) – and thoroughly overshadows it when it comes to macro-dynamic expression and bass power and control.

By having the Audio Research Reference 6 preamplifier within the context of your system you'll feel well confident that it will never be the bottleneck inhibiting your stereo's full musical expression.