I am planning an amp build using a pair of TO-264 devices on the output of each channel, but am having trouble finding a matching thermal pad which is not electrically conductive. Datasheets for Bergquist suggest there should be Sil-Pads of appropriate size, but I cannot seem to find them in-stock at my usual suppliers (Arrow, Mouser). It looks like the DIY Audio Store's Keratherm pads will work, but the price is rather steep.

Does anyone know of thermal pads of sufficient size and affordable price? Is it possible to make these work with careful orientation?

Just got a Sansui 5000. Heatsink very hot. Found out the bias in this thing was running at 450ma! Ouch. Lucky It dont have blown outputs. Was able to turn pot all the way own and get 26ma but something is obviously wrong with this driver board. Heard there is diodes that go bad and there is a mod but cant seem to find how to actually do the mod. Anyone familiar with this mod?

Hi

Does anybody know a good source in the U.S. for a Mark Levinson 37/39 drawer belt? I tried several generic belts of about the same length but result was not satisfactory (in terms of drawer operation). Could not find any link in the archive.
Thanks

Hi all
anyone can post some detailed picture of this mid range woofer?
I have to recone it, want to be sure about to use same materials, wave forms etc
thanks

FS: enclosures, punches, crimping tools, books, LPs, more

NEW sealed Moduline Electronic Instrument Enclosure, 17" x 14" x 5" Blue | eBay
GREENLEE 9/16" PUNCH, in excellent condition
GREENLEE 1-1/4" PUNCH, in excellent condition 783310040088 | eBay
GREENLEE 1-15/16" PUNCH, in very good condition 783310040088 | eBay
GREENLEE ROUND PUNCH, 1.334" diameter, in very good condition 783310040088 | eBay
GREENLEE 1" SQUARE PUNCH, in excellent condition | eBay
MOLEX hand crimping tool, model HTR 2445A, in excellent working condition | eBay
VACO crimping tool -- https://www.ebay.com/itm/293604162383
Many jazz/rock/classical CDs -- https://www.ebay.com/itm/293714995043

Electronics and audio related books, reel to reel prerecorded classical/jazz tapes, 300 mono RCA LPs, etc.
https://www.ebay.com/sch/marion8pvg/m.html?_nkw=&_armrs=1&_ipg=&_from=

Following items for local pickup in Madison, WI area, due to weight. More info/photos on request.

Cambridge SoundWorks, pair of subwoofers & small satellites, good for video.
The two subwoofers can be used separately however you wish. $100.
Hallicrafters S-85 shortwave communications receiver, looks very good, works. $95.
Nikon stereo inspection microscope w/heavy stand $150. Very good for SMT work.
The Advent receiver $100 (with Holman phono circuit) 15W/ch amplifier, good sound.
More info: https://www.hifiengine.com/manual_library/advent/300.shtml
Rotel receiver
Yamaha receiver
Infinity speakers, smaller cabinets
Proton 100 FM/AM radios, have two, $50 each. World's only biamplified table radio (and the heaviest, too).
Akai GX-280D-SS reel to reel tape deck $395. Very good condition, with original take up reel.
More info: https://www.hifiengine.com/manual_library/akai/gx-280d-ss.shtml

Would anybody have a couple of these they could spare?

Ta,

Mark

A couple of days ago I was browsing the net for details or mods to the Seas Idunn design when I came across a comprehensive addendum to a Seas 27 TBCD/GB-DXT tweeter equipped speaker which I am convinced was the Mark K design*(but might not have been!) . It was a very comprehensive set of plots showing the subtle changes to the level and crossover frequency by changing 2x resistors....I think there were at least 4x variations. I thought I had bookmarked this but it seems I didn't and after spending hours looking for it today I have given up.
Does anyone know or recognise the web page I describe and be so very kind to direct me to it? Very much obliged and thanks for reading this...🙂
PS* the web pages may have been on the "Audio Excite" "Prestigious Two-Monitor DXT" as I'm pretty sure the resistors were R1 and R2 that were changed. I've looked everywhere on this site though.

Well I kept on looking and now found the page, it is here: www.audioexcite.com >> Blog Archive >> Prestigious Two – Monitor DXT Tweeter Level Option Update!

Sorry for the question but hopefully someone will find this interesting too.

Les

When you have done a autooroute is there a way to reset (not undo)the remove and start from scrats?
I have sen that it doesnt route as the schema is Why??

Amp came in for repair.

Kind-a works but the output is heavily distorted and doesn't even look like a sinewave. No power light on, no protect (LEDs work, tested them outside of the board).

It's the big brother of MTX 7801. I've checked your guide Perry and followed everything through it.

Optocouplers, N5532, rail voltage, supply voltages are all fine. Oscillation is as it should be according to the Perry's manual. I've re-soldered the inductors just to be sure. I've used jumpers to preamp bypass.


From the pictures:

The clean sinewave is taken at the jumpers.
The distorted one is at the output of the amplifier.
It's the same if i re-connect the pre-amp section.

I've noticed that the output filter caps get warm. They are nichicon 63v 470uf, doesn't seem they have been changed but in Perry's guide the ones over there are Panasonic, but the voltage and capacitance can't be seen.
I took out 2 caps and measured them - they read just fine 501uf, ESR=0.1ohm (leads resistance not taken out).

What else to look for ?

Hello.
Amplifier processor PRIMARE SPA21.
Only one anolog input working.
Sometimes not respond to remote control.
The display is very low contrast.
No video output.
Its work only one analog input,2 channes works fine.
No video output,no possible to change the settings.

Can you help me with repairing ?
If possible to make factory reset on this amplifier.
Regards
SM

PRIMARE SPA21 SURROUND PROCESSING AMPLIFIER SM Service Manual download, schematics, eeprom, repair info for electronics experts

I have heard several times from different users that this is an exceptionally good sounding CD player. I haven't heard until now.

From the internal view (SMPS-PCB instead 50Hz resp. 60 Hz transformer, DVD/MP-3 PCB and Laser etc.) I wouldn't expect such listening results.

What is here very special in opposite to usual DVD concepts ?
Service manual is here:
HARMAN-KARDON HD980-230 REV1 CD PLAYER Service Manual download, schematics, eeprom, repair info for electronics experts

Thanks for an advice.

The HD-970 has already been discussed here - go to
https://www.diyaudio.com/forums/dig...mon-kardon-hd-970-modded-world-beater-12.html
but this is an other version with other PCB's.

Hi all,

I offer here a WHAMMY pcb.

Thread: "WHAMMY" Pass DIY headphone amp guide

Costs: 25€
Shipping in padded envelope (no tracking, no insurance):
- Germany (without islands): 2€
- Shipping in EU: 4€
- other countries /options please ask

For sale:

4x Ohm TRS-115 mk1 450,- per pair 800,- for all four
2x EAW JF260 1000,- for the pair
4x Nexo Alpha S2 copy (identical from the inside, same tuning etc, 18mm birch ply etc.), loaded with B&C 18PZ46 drivers. 3200,- for all four.
2x Bandpass sub like Nexo LS400 (empty) 250,- for the pair
2x 18Sound 12NLW9300 (good condition) 400,- for both
1x BMS 4548-16 OEM 60,-
1x L'acoustics HP BC122 (freshly reconed) 150,-
2x Master Audio SM4000 amp (2x3000 Watt @2 Ohm stable!) 725,- per piece, 1400,- for both
1x Void Infinite 7v2 950,-

Price is in euros and can do a discount when more items are bought.
Feel free to pm for more info or pictures (located in the Netherlands).
Shipping is certainly possible for the smaller items, I do not have any experience with pallet shipping, but I am sure we can work something out if it is needed.

For sale:

3x Powersoft K3-DSP (ex install) 1200,- per piece.
1x Lab Gruppen PLM12K44, +- 1 year old, looks like new (no scratches etc, and comes with original box) 4200,-

Prices are in euros, shipping in EU is possible, overseas probably also but don't have much experience with it. For more info pm 😉

Hi all,

got micromega st3 salvaged by previous user - it had overheated trafos on DAC board with fried 1305 dac chips and output op-amps. Got dac chips replaced with 5$/pc from aliexpress, restored all op-amps, power etc. Got nice sound, clean output.

BUT - there's a strange option of double speed play - dunno why it is in CD player, but still. Once pushing x2 button, it plays on double speed just fine, but linear output distorted with pops and clicks and loud noisy sounds like... heavily scratched vinyl. Well, at normal speed it plays just fine, but on x2 - pops and clicks, however the original sound is also there.

Is it possible that I got counterfeit 1305 which are re-labelled something pin compatible but without x2? or something wrong with opamps?

no pops and clicks with spdif output to external dac on any speed.

Once the driver holes have been cut and countersunk and the veneer applied over them, what is the recommended process to cut the veneer out of the speaker holes in a perfect circle ?

Looking for good physical condition and 100% operational. Let me know what you have. Thx Peter

Long time audiophile here, but new to the group. Great forum!

I am in consideration of a 21" Eminence subwoofer (https://www.parts-express.com/pedocs/specs/290-5662--eminence-nsw6021-6-spec-sheet.pdf) to augment my 4 other Dynaudio subs in a large basement setup (they are great, just not big enough). The speaker is 6 ohms and most are using large (at least on paper) Behringer or Crown type pro amps listed at 2000-3000watts, which is likely more like 800-1300watts rms. As a higher end HT guy, putting pro amps in my room seems a bit like sacrilege. I'm not really sure why to be honest, so I'm opening my horizons.

I don't know what amps are out there. I've been looking at Crowns mainly just because I know the name and they are USA made. If realistic, I'd like to spend around $500 - lower the better and I don't mind buying used. It seems like there are a lot of pro audio amps around and each year varies a bit w.r.t. functionality. I've been having trouble finding one that meets my exact needs:

• 1000-2000watts rated power - higher the better, a bridged 2 channel is fine
• Supports 5-6 ohm load (sub is rated at 6 ohm, but it can dip a bit lower)
• Under $500 (used street price is ok)
• 12v Remote trigger capability (don't really want to use a smart power strip)
• 15-17hz high pass capability (to protect low end xmax/over-excursion its recommended for the Eminence sub - the ported enclosure is tuned for 20hz. I will use my avr to low pass it)

-The Crown xls 802 has a 15hz high pass but alas it is not stable below 8ohm when bridged, nor does it have a remote turn on. The newer Crowns only have a 30hz high pass which is too high.
-The new Berhringers have good power and nice DAC's in them, but require a fan mod and have no 12v trigger
-Some of the QSC like the DCA3422 have the power and remote turn on capability but their high pass filter is only 30hz which is way too high.

I figure some of you pro audio guys out there know these amps backwards and forwards and can suggest another amp. I'm sure I'm missing some older models in my searching that may have the features I need. Its funny when I think about car audio sub amps, MANY of them have all of these features, but its a bit of a needle in a haystack exercise to get it in the home. I know I can get a smart outlet for the trigger and I know I can get a minidsp HD for the xover, but these are essentially Band-Aids - I'd love to have an amp that just does all that for me. Thanks.

I am trying to build a folded exponential horn with a collapsible throat, for a mechanical phonograph project, which will also be used with a tiny fullrange unit.

Would a throat lengthened/shortened about 4.5cm have any audible difference in a 130cm horn's sound quality? 😕

The horn will have a throat of 16mm, a mouth of 75cm in diameter, thus reaching down to 228.8hz...

I recently completed a halfinator build.

I wanted to add Bluetooth and a preamp in order to get the most out of the speaker. I wired these up today and when I tested the Bluetooth and preamp only the tweeters were producing any sound. Went back to original set up, still only sound outbid the tweeters. Swapped amp (tpa3116 mono) with a new one in case is wrecked the amp, still same.problem.

I didn't hear any worrying noises to indicate I damaged the hp10 drivers.

My amp has a startup plop, this has also been replaced by a click from the tweeter.

Anyone have any ideas? I really hope I've not ruined the hp10's but don't see how I could have.

Pre amp: XH A901 NE5532 Tone Board preamp Pre amp With treble bass volume adjustment pre amplifier Tone Controller For amplifier Board|Operational Amplifier Chips| - AliExpress

Bluetooth: Bluetooth 4.2 Receiver Board CSR64215 Bluetooth Module Lossless APTX Wireless Bluetooth Audio Receiver Board|Integrated Circuits| - AliExpress

Amp: TPA3116D2 Mono Amplifier Board 100W DC 12V 26V High Power Audio Digital AMP Module Sound Speaker Board Volume Control|module dc|module powermodule board hot - AliExpress

The noise stops when the line/tape button is pressed in (that button changes the EQ application from the line stage, to applying it to the tape buffer circuit). The EQ circuit is entirely passive, with a few polystyrene caps, a few (recently replaced) electrolytics and a few film caps. Also, the 960hz slider does not boost in the same channel that has the noise, but it does cut. Any ideas? It must be a passive component that is introducing the noise, I assumed it was broken graphite in the 960hz slider acting as an antenna.

I am having a strange problem with this amp,
i use this amp in 2ch mostly,but have speakers hooked up for 5.1 for movies,
very randomly (can be a hour or 8 hours use ,in fact not at all for days) in 2ch mode it will produce a loud static hiss though all speakers ,music is not heard at the same time i think, it lasts for about 5 sec and then silent ,i can turn the hiss(crackle) down if i get to it fast enough with volume ,
once silent it will not pick up any signal ,once i turn it off and back on its normal till next random time to do this

if any one has seen this before or repaired this problem before id love to ear from you
mike

ps , this is my first post so hello to all ,😱

A nice high Early Voltage is important in certain types of topology but this spec is hardly ever given in data sheets (although it can be estimated from family of characteristic curves). My question is does anyone have data as to which BJT's perform best in this respect? Especially complementary pairs. I would guess that video output transistors should be pretty good but would welcome further information from anyone who has looked into this.

Ive been running my tseii for a while now and all has been great. I decided today to check/adjust my bias since it had been a while. I am seeing some odd behavior while trying to set bias on the right channel. Im running just under 400 b+ and b- is showing around -200. I am trying to set current at 75ma. The left channel is nice and stable but the right channel continues to drift after i make an adjustment.

I checked the bias voltage at the 300b and it is around -66v and is stable even when the tube current is fluctuating. My first thought was the tube was the issue but I swapped tubes and the issue stayed on the same channel.

What should i be looking at to solve this issue? Thanks for any help

Hello everyone!

First of all, sorry my bad English.
I'm typing here in Finland...winters coming...

Anyway, I'm building Triode Dick's KT88 PP Amp in stereo.

i'd like to know what are the resistors R17 and R18 in The chema?
Are they 1R and what wattage?

Thank's a lot, if anyone can help me littlebit!

Juha from Finland.

http://members.home.nl/triode.dick/Bill/schema_versterker.GIF

In a month I'm moving into a new house and I'm working on designing a music-focused sound system to go in the basement for a DJ/dance party setup. I've put together a two-way top/main that I'm really happy with thus far (passive-crossed PRV 8MR-500NDYv2 with a B&C DE250 on the ME20 horn), but I'm struggling with what to do for the bass/sub area.

Specs: Room is approx. 14 x 24, maybe 8-9' ceilings. Drywall + carpet.
Planning for two mains and two subs in opposite corners - mains mounted on ceiling, subs on the floor. All enclosures must be DIY. Crazy SPL not required but should have plenty of headroom as the space will (hopefully) be full of bodies from time to time. Pro amps & EQ will be used - subs will probably run parallel off a single channel. Music will primarily be house, disco, techno, funk & soul. Hoping to build at least one sub in advance.

Now questions:

1) What size subwoofer/bass cabinet(s) is recommended for this space? I had initially planned on 2x18's but after testing one main in a similarly-sized basement room with a single low-power 8" sub driver, I'm wondering if 18's are overkill. Certainly a smaller driver would save some floor space. I don't need ridiculous low bass (my neighbors foundation is merely 4' away) but would like plenty of 'kick' to the drums; I suppose that means transient response is as or more important than depth?
2) Would a simple reflex cabinet suffice? Simplicity of construction is a must, and smaller is better (4-6 cu.ft. is doable, as long as it's tall and shallow). I understand the trade-off from sealed to vented, but I don't know if that will matter for my application?
3) I'd prefer to stay under $100 per driver. I had initially pegged the Dayton Audio PA 18" as I won't need crazy power or XMAX, but maybe I've overlooked something? Or, if going with smaller diameters, what would you recommend?

Thanks all.

I have 4 un used SJDP120R085 for sale. Make offers.

I have been Sitting on Purchased Speaker Driver Units to start a Three Way
Open Baffle Build for a while, and this is now looking to be my Winter Project.

I have selected Two Way box speakers to use while the Quads are out of use and the OB's take up their position.

I would like to try out a Home Built Ripole with the Quads before I dismantle the Stacked 57's, and then try out the Ripole as the first OB Sub Woofer to work with the rest of the OB Array .

I have an itch to Scratch and would like to produce a
Ripole Sub using 4 x (very used) Eminence Beta 15's, where there will be
2 x Beta's mounted in a Framing, and have a 2 x Driver Ripole produced for each Channel, to have the experience of the Ripole as a Sub Woofer Design.

I have been extracting various information supplied on here to produce a Ripole using 15 Inch Drivers.

To attempt to get the Framing Dimensions as accurate as possible to match my drivers.
I have used an information shown in a Post where the Beta's Xmax is less than 10mm at 4mm,
the Front Chamber Opening is to be calculated at 0.25 x 823.7 Sd .
The Rear Opening is to be calculated at 0.5-1 x 823.7 Sd.

I have never built a Speaker before of any type, and my Maths are not quite working out, as I don't seem to be creating any Width to a Chamber, that is close to some of the Build Plans I have reviewed ? .

I can forget this and use a Plan for a 15" Driver I have downloaded from this Forum, that has a Side Panel Dimension of 412.74mm (H) and 419.1mm (W).
The Font Chamber Opening is a 152.4mm (W),
the Rear Chamber Opening is a 76.2mm (W).

If there is a benefit from using the Driver Specification to produce the dimensions ?, then this is how I would like to proceed, and would be greatful if I can be given a Pointer to Side Panel Dimension and the Chambers Width Spacing.

The Beta's are 384.8mm in Overall Diameter and has a Depth of 153.7mm, my Side Panel dimension on Paper to accommodate this Drivers dimension is 435mm x 435mm, which was simply produced by adding an extra 25mm to the Perimeter on each plane.

Thanks in advance for any advice offered.

Hi all of you. I am new.

For those who had heard and used the Hiquphon OW I tweeter.

Do you like this tweeter? What is your experience on this tweeter? Is difficult to work with?

Thanks and regards

Jason & Co.:

Can you provide some clarity around what is included in the new 4U / 500mm Dissipante chassis mentioned in the diyAudio store? The "Ultimate 4U 500mm Chassis" thread has discussed a lot of options (UMS drilling, base plate, custom rear panel, etc.) but it's unclear what is actually included in the Store's offering.

Also, is this chassis even available? When do you expect shipments to start?

Thank you,
Scott

Many years ago, maybe 10-15 years, I purchased from either Korea, Taiwan or Singapore a pair of transformers. I could even have bought them from German company Welter Electronics, but the product code doesn't add up.

I have already forgotten what I intended to use them for, but could have been intended for 2A3-SE or EL156-SE, but ... I haven't the slightest clue.

Here comes the mystery. I simplyu measured the resistance and the yellow wires indicates 0 - 4 - 8 - 16 Ohm secondary/output.
But primary/input makes me confused. The two red and the two green wires have a resistive connection and my guess is the following:
Between the green connectors I measure approx. 190 Ohm/9.16H - that could be a 3.5k Ra connection.
Between the two red wires I measure approx 170 Ohm/7.57H - could be a 2.5k Ra connection.
Or 5k/3.5k ...??

Transformer is (when looking at the pic) H 3,5" x W 2 3/4" x D 2,5". Iron core is approx 1 1/4" x 1/2".

What do you experts say, what did I grant myself many years ago? maybe someone recognize it ...

And no, it is not a mains transformer; I've got two of them.

Attached images, showing picture of the transformer and a graphic of the primary and secondary.

If someone used the term "4x oversampling", are they referring to figure 2, 3 or 4? (or something else entirely?)

Regards.

I own a DACT CT-100 phono preamp module card. Its installed inside a diy preamp metal cased along with a DACT ct-101 line stage module, a DACT CT-2 10k attenuator and Dact CT-102 power supply. Sort of a kit.

Currenty my turntable has a Sumiko SHo moving coil cartridge, 1.8mV wired with 1 meter of Discovery cable from cartridge pins to male RCA for connection at the phone stage case RCA’s.

I believe the hum issues are related to CT-100 installation or operation, not the tonearm wires or cartridge.

To identify cause I have done the following:

I.
The hum is on both channels when I select the phono for playback, even if the turntable motor is off.

With unit powered, cartridge output cables disconnected from CT100 input RCA’s I get white noise if volume is turned up. The white noise goes down with volume and its much lower than music playback. All OK.

If I open the case and put my finger near, or touch, the center wire connection inside the case input RCA (where RCA center pin is soldered to same wire as connected to CT100 IN1) I get a hum that varies with the distance between my finger and the solder point. The wire connecting the RCA to the board is shielded, and shielding is soldered together with cable return wire to CT100 board connection point.

The same happens with the other channel IN2.

I this hum normal?

II.
The RCA connector installed to chasis IN1 and IN2 is a WBT Nextgen (which has an insulated plastic body fixed from the outside by a metal collar acting as a nut. Said collar nut does not touch any metal at all as it is screwed to the RCA plastic body).

If I touch the RCA metal collar outside the case, I get the same hum as I described when my finger is near the female RCA solder point inside the case. I believe it is due to the metal collar acting as "antena" for my finger near the same center pin of female RCA for IN1 and IN2.

Again… I this hum normal?


III.
When I connect the cables coming from the cartridge to RCA IN1 and RCA IN2 and the tonearm ground cable to the case uninsulated ground post ( as stated to do in the phono card installation instructions), I get hum. Less than describe before but hum.

The rest of the CT100 installation includes a ground cable connected to the same CT100 ground lug as the case ground post for tonearm. That cable is fixed to the same point in the case as the ground wire connected to the CT-101 line stage pre board.

Any advise on how to deal with this?

Thanks to all.

My friend just built a Home theatre and has asked me to build speakers for him.

Some high level project goals:

- The budget for the L + R is around $2k.

- He wants it to be able to play loud, with lots of deeper Bass (40-70Hz),

- but also sound "high end" at lower volumes

- The cabinets cannot exceed 10" baffle by 60" tall (maybe 16" deep at most)

- He is open to Subwoofer augmentation of the lower LF

- Primary use, Home theatre and dance parties , secondary use, Audiophile listening...


Thinking of building it around four Dayton RSS-225-8's... still deciding on mods and tweets


Thoughts...

The ultimatest compact disc turntable ever made?
Who have heard this model in combination with a top class DAC ?

here some URLs:
New Products - PiTracer CD Transport
Stereophile: 47 Laboratory 4704 PiTracer CD transport
SoundStage! Equipment Review - 47 Laboratory Model 4704 PiTracer CD Transport (5/2004)
47 Laboratories Factory Tour [English]

Has anyone recaped/modded one of these units. As good as it is(dispute 20 year old components), is there points(no major changes) to be improved. I'm thinking to replace the Dig out with a 75 ohm BNC, and RCA analog outs. The cooling fan is needing replacement. Since I only use it for CD playback both analog and Dig, and the unit works without the video out connected to the PS, any benefits leaving it disconnected? I ask for those with experience because I don't want to repeatedly disassemble the unit. Experience talking here.....

Input filter considerations for EMI mitigation -- from Tobias and Florian at Omicron Labs:

Webinar: Input Impedance and Filter Stability of DC/DC Converters - YouTube

Hi.I cut these open baffle speakers enclosures and my friend assembled them.He says he gets lots of bass but not happy with treble.I advised him to add a Tweeter with a simple serial capacitor but he does not accept it.He told He want to get better treble by playing/changing crossover.Any advise about crossovers to improve treble?

First off thanks for any help you can offer. I have a Ampeg B500DR bass amp that won't get put out any bass guitar sound. When I turn up the volume the fuzz gets louder but no signal output. There is a relay I was tapping on and after a few taps I resistor in the power section fried. I attached the block diagram but could really use the schematics if anyone out there has them.

Good day all,
I have found a few of these regulators between my spares. I intend to build a preamp soon, would these be a good option for regulators in a power supply ?

why is it somtimes when i power on my unit it may come on and somtimes not??...,, somtimes i will switch on and the signal light will blink accordingly but no audio atall,,, if i switch it off and back on rite away it will come on and start work as normal,, why is this ?

Pic 1

Pic 2

Pic 3

$125 **

Suppress electrical noise in sensitive devices.
Very effective in eliminating line noise.
Improvement in sound quality.
Very effective, especially in congested urban locations.
Provide galvanic isolation to protect against electric shock from the mains.

Manufactured by Electromagnetic Industries Model 541-1-1
Rating is 3KVA 60Hz 120V primary/secondary
80 deg C rise
Insulation class F (which is 180 deg C)
Leakage 10 microamps max.
Weight approx 66 lbs
Approx 16" diameter and 3.5" height

I have more than one available. Appear NOS.

**Prefer local pickup in Moorpark, CA. Will ship within CONUS (Fedex ground home delivery estimated to be $70 to $150). PayPal OK. No returns. Reasonable offers considered.

I'm going to order a batch of Lynx 3.01 PCB's for my Orion project. To keep the price down I'm thinking to order 50 boards (I need 10), so if anyone is interested, let me know.

The price will be 17 euro excluding shipping.

Looking for upto 8 NXV200 modules from Aussies amplifier (Anthony Holton) Who still has these modules and isn't using them?

Also the 350 or 500 W versions are welcome.

Thanks!

I'm continuing with my projects, which include doing some much-needed cap replacement on some vintage amps, receivers, etc. I've decided on Nichicon because they have a huge variety of caps and I'm having better luck finding the sizes, values, and mechanical specs (mounting points and exterior dimensions).

HOWEVER...

There seems to be a big bunch of info about which Nichicon grades are appropriate for what circuits. Everything I've seen in both Nichicon data sheets as well as stuff I've read here tells me I should be looking for KZ, FG, and KA in the audio path, and KG/KS for the power supply and supporting circuits.

I'm getting ready to put my order in, and I've been discussing it with a product advisor at one of the biggest parts houses. Today I get an email from him telling me I should be looking at ES for the signal path, and FG and KZ for the power.

That doesn't make sense to me. I haven't seen an FG above 4700uF, and definitely not in KZ, where the highest value appears to be 1000uF. So how can I build out the power supply with those grades? And I've never once seen anyone here recommend using FG or KZ for power - only signal. Did the guy get his recommendations backwards?

What is the most appropriate cap for power filters, as well as the supporting regulation circuitry? What about the stuff like audio paths, especially when you get into preamps?

TIA

In short - what should I use where, and what should I avoid using in particular situations?

hello
anyone has 1 eminence 875 8” 4ohm for sale?
NOS used or brand new
not rebuilt

thanks

I only get 0.64 volts on pins 8,11,12 of the 494

Also the transistors that connect to pin 8 also have 0.64 volts

Any ideas ?

Because my datas are from the January 2004... I would like to update something. Thanks 🙂

Hi ALL,

Does anybody still works with the TEF20 analyzer? I am looking for a software module for this analyzer.

Its called SLX. (soundlabs extra)

If somebody can help me with that, let me know.

Greetings,
Marcello

Greetings,

I have an issue with one of the tweeters,
the problem is that tweeter activates somewhere between level 9 and level 10.

I have checked the board and found power resistors which were cracked and replaced them, but still no luck.

Can someone help with what should I check next?

I’m working on a Memphis amp and both output filter caps 10uf 250 volt are bulged on the top .

So more then likely they are blown .

Wondering if they are bad would that affect the output as far as the gain has to be 3/4 of the way up in order to hear the test speakers

Hello, received this amp, blown output.
Removed all fets, installed new drivers, checked everything, seems ok.
Gate Signal on low side also ok.
Mounted new fets, it blows some fets directly.
Removed all fets again, new drivers, and checked with two fets, bank by bank. One side ok, if i mounted the fets on the other side, directly all drivers blown again.
Removed fets and drive board again.


Checked the pins on the mainboard for the drive board. I have a saw tooth on pin 1, 10, and the 3.rd row, Pin 2 and 29.
I dont know what happened here

Hello,

I'm having some issues with a luxman R-800. When I got it the symptoms were : no fm reception and popping/crackle noises when fm selected accompanied by wild movements of the two meters (centre and signal strength). The auxiliary inputs work fine so it's not the preamp. I replaced two transistors in the front end portion (q102 and 103) with 2n5770 as q103 was an infamous "flying saucer" and actually had a gain of 1 when tested. Now I still haven't got any reception (that is unless I directly connect an fm signal generator to the antenna with its output at max and I only just get enough deflection on the signal strength meter to actually notice it, and with fm muting on it stays dead silent) and the popping sounds are still there although a lot less perceptible. I don't really know where to start although I can already say that the +12v rail is present even if rather at 13.2v.


Thanks in advance for your help

Hello All, Found this whilst out trawling.

Australian, Graham Dicker designed, Aust $39.00, DIGI-125 amp module kit, ( http://www.bettanet.net.au/gtd/kits.html ).
7 transistors, 2 diodes, 8 resistors, 3 capacitors, no adjustments, +\- 38 Vdc supplies, 125w/4ohm, (200w/2ohm modification).
0.06% at rated power, 0.01% 10Wrms, 100Khz power bandwidth, DampingFactor - 90 wrt 8 ohms.
Looks to me like an easy, cheap, quick way to build acceptable surround/triamp setups etc, economically.
I am keen to hear experiences, and sonic critiques, and mods -
27,000 sold can't be all wrong maybe.?

Regards, Eric.

What should I look for ?
What makes a BJT with high Early voltage ?
What kind of BJTs have high Early voltage ?

I've been experimenting with DMOS since SY got me started with "His Majesty's Noise" RIAA preamplifier.

It seemed to me that one could self-bias a DMOS and use it as a current sink. Sweeping from 10Hz to 10MHz and measuring group delay, you can quickly determine whether the power supply/regulator is stable.

The IXYS IXTU02N50D has Ciss of 120pF. The gain plot uses IXTU02N50D, not the DN2540 shown which is 200pF.

Restarted at the right place

Hi guys

I am trying to design a small Sub, nothing big and am still learning how to use and interpret WinISD.

I have an existing MDF cube I would like to use, 27cmx27x27cm inner measurements (~19.6 liter) and played with a couple of drivers . I do understand the meaning of F3 but the curves (see attached) look quite a bit different between vented and closed and I don't exactly know how to interpret them. To me the orange one seems to be the best, but I might be wrong.

Any help is appreciated.

Kind regards
Phil

I need a cheap/quick build in a smallish box.

I am selling my house and taking my good stuff, but need to replace it with something tolerable.

Any recommendations?

Thanks All!!

So recently i purchased some EPCOS capacitors online from a local store which is not an authorized distributor for TDK, but seems to have lots of different known brand items in the store and is well reviewed. When the capacitors arrived, i noticed they deviated a bit from the datasheet. they don't have the "PET" marking on the sleeve as described in the datasheet, and the pins are attached to the capacitors in a different position. I'm attaching pictures of the capacitors in case any of you are familiar with the brand and have purchased confirmed originals and know if they look like these or not. At the moment i don't have a way to measure them, and when i contacted TDK, they basically told me to look at the datasheet, which i had mentioned to them i already had.
Thank you!

I did a lot of amateur research (amateur although strictly confined to industrial experts’ writings, not mumbo jumbo) into PC watercooling to try to figure out how to make a good coolant, since coolant makers offer voodoo products with ingredients that aren’t good (like dyes, fluorescents, and opacifiers) as well as trade secrecy. I discovered, for instance, that an industrial consultant for said glycols (whether ethylene or propylene) cannot be less than 20% of a water solution or they will develop harmful biological growth. The solution will become quite harmful to the metals it’s supposed to protect.

That contradicted an absolutely huge amount of amateur advice about “splashing” glycols in mixtures and using small percentages, like 5–10%. Apparently, too little glycol is worse than not adding it at all. That’s the opposite of the amateurs’ advice. They claimed that even this smaller amount of glycol will function as a biocide and/or increase lubrication and/or improve corrosion resistance. And, some commercial small business watercooling coolants claim to use less than 20% glycol, so they are apparently a bad choice for your equipment.

One of the things that I focused on a lot was on stopping the corrosion of copper. Since copper is commonly used in speaker parts (amp internals, wiring/connectors, etc.) I felt that I would share some of what I learned with the community here. Specifically, it’s about what can be done to treat the copper to reduce its penchant for corrosion due to air exposure. The short answer seems to be a dip in a tolytriazole solution (tolytriazole dissolved in ethanol).

However, other solutions may be even better. Some may be considered ‘good enough’ depending on the criteria. IBM uses BTA (benzotriazole) for its computer watercooling systems, probably because BTA is much more water-soluble than tolyltriazole. However, it may be more optimal to dip the copper parts in an ethanol solution of tolylriazole before putting it into a loop containing BTA water.

There was an interesting study involving the preservation of copper artifacts. Only one of the tested solutions stopped corrosion completely and it wasn’t one of the solutions using distilled water as the solvent:

BTA (benzotriazole) + AMT (1,3,4-thiadiazole) in ethanol

The ratio was .1M BTA + .01M AMT. Surprisingly, such a small amount of AMT did make a difference.

The same combination in distilled water had comparatively good performance (versus the other chemicals and mixes beyond the one cited above) but corrosion still happened. I believe that the artifacts were kept in the liquid. I do not know if the AMT, for instance, would make a difference for parts that are removed from the liquid. I also don't know how finger oils/contaminants will interact.

I also do not think that the study included tolyltriazole. Here is a link to the study: A Corrosion Inhibitor Test for Copper-Based Artifacts on JSTOR

Tolyltriazole is apparently commonly used in industry, not only for some automotive corrosion resistance (like in some antifreeze mixtures) but also to protect copper parts from tarnishing from air exposure and such. As far as I know it is common for copper parts to be dipped in a solution of this.

advantage (versus benzotriazole) : thinner yet more effective coating (more hydrophobic) than benzotriazole

disadvantage: poor water solubility

There is also a longer carbon chain triazole. That is napthotriazole (related to napthalene — moth balls). It was briefly used in the laundry business. One piece of data I remember reading gave it better protective qualities than even tolyltriazole but I did not find any chemical companies that offer it. It would certainly not be soluble in water but if used with the dip method (ethanol?) might be better than tolyltriazole to coat copper to protect it from air exposure.

Copper oxides have very low thermal conductivity when compared with the copper metal, so a thin protective layer is better for PC heatsinks and watercooling waterblock channels than oxidized metal. I assume the electrical conductivity is also much lower.

(Despite the reduction in thermal conductivity and the problem of unsightly corrosion—that gets worse—many in the PC water-cooling community recommend using only distilled water with a silver coil as a biocide. That does not seem to be good advice due to the solution not protecting from galvanic corrosion, silver exacerbating it due to the presence of nickel in particular, there being no pH buffer, etc.)

Another mistaken bit of advice from amateurs (propped up by some small businesses) is to use silver as a biocide. For one thing, silver is not compatible with triazole inhibitors. It bonds with them, making both the silver and the triazole neutralized/worthless. Then, there is the issue of silver and galvanic corrosion.

Triazoles are rather stable in water and also harmful to aquatic life (not just people) so they shouldn’t be flushed down drains. They should be disposed of correctly as toxic waste. Their vapor pressures should be low enough for them to make evaporation of the solvent prior to disposal possible, for greater ease of disposal (particularly if the solvent in distilled water). You should also use protective equipment when dealing with them and all that. Research best practices if you handle them. They aren’t the sort of super-toxic stuff that needs a fume hood but you also don’t want to breathe the dust or spread it around. BTA is used in amateur and professional film photography. Handle with an appropriate level of care. Tolyltriazole may be less toxic since it’s much less soluble but I haven’t looked into that.

The copper artifact protection article said one of the goals was to find a less toxic alternative to triazoles. The result was not good for anything except a triazole.

(Just in case anyone is also doing something involving watercooling… do note that aluminum and copper do not play well together due to galvanic corrosion. Silver coils (as biocides) with typical nickle + copper parts also are a questionable combination. The easiest way to avoid galvanic corrosion is to use a single metal but in PC watercooling I’ve never found a single vendor selling copper fittings. They’re always nickle plated. There is also possibly a concern about the flux used. Also, various pH buffers like borate are often used to stabilize coolants so things aren’t always very simple.)

Copper has some wonderful qualities but resistance to corrosion is not one of them. I don’t know if there is an alloy that provides close to copper’s benefits without the ease of corrosion but I doubt it. Gold certainly isn’t a good alternative for electrical conductivity but it is great for corrosion resistance (and thus could be considered ‘good enough’ for conductivity since it’s so stable versus corrosion that engineers can build specs around it more reliably). Yes, I know that pure gold isn’t an alloy. I don’t know what industry is using to reduce silver’s tarnishing. Perhaps it’s tolyltriazole as well, or some sort of alloy. I haven’t investigated silver cables, connectors, and things of that sort.

One basic point of this topic is to point out that copper should be, at least, dipped in a protective triazole for most purposes — particularly if not protected by some kind of visible coating. And, even then it’s probably best to have it protected inside of that coating unless air can be permanently evacuated and replaced with something inert like argon.

I have read that the Magnepan Tympani III uses copper wire and that Magnepan doesn't replace corroded copper wire when refurbishing that speaker for customers. Instead, the panels are replaced with aluminum wire. I have also read that Quad ESLs have used copper wire. So, protection of electrostat wires from corrosion seems to be important if one plans to use copper, particularly for refurbishing according to original specs. Hopefully this post will incite people who might otherwise just use bare wire and hope for the best to consider the possibility that some sort of corrosion protection might be in order, depending upon the situation.

Have 3 NEC (some years old I believe) Supercaps reading 0.47 Farad 10 Volts.
Have no clue of price but come with a sensible offer, can be money (Paypal friend and family) or something to trade (in need of bigger heat sinks).
Sending from Sweden so preferably Europe.

I have a Rockford Fosgate Punch 600x4 that had 1 bad channel. I replaced the outputs, gate resistors, emitter resistors and current sense resistors. The channel plays fine and sounds just like the other three bit there was a problem regarding the current sense resistors.

I mistakenly ordered 0.05 ohm resistors in a 1206 size, when they are supposed to be 2512. Will these resistors fail prematurely due to the smaller size. Thanks.

Hello, new member here. I am having trouble figuring out what is going on with this receiver I've been working on for awhile now.

It's not passing signal past the tone board's 1st transistor and voltages are off on the tone caps board, especially that first transistor. I've replaced the first transistors on both channels and no change really.

It has a sort of loud crackley distorted sound when the volume is turned up, but it is almost impossible to tell it's anything music related through the noisiness . It's only a in and out crackling output. I have recapped the power supply board, and everything was at their correct voltages on that board.

What could be the issue?

Hi

Just picked up some ESL 57's, and I know the impedance curves are "challenging" for amps.

I have a stock Marantz 1030 I wanted to try with them, but am concerned about it being able to manage the low impedance dips.

Thoughts?

Thanks!

P

Trying to model a transmission line. Selected the TLine component from the Analog Primitives > Passive Components library. No matter what I put into the "VALUE" field, none of my inputs seem to take; get applied to the model.

Here's what I see after I apply values and reopen the part editor:



As you can see, every property, including Z0 that I tried to set, is "undefined".

When I try to run AC analysis on a simple circuit I get the following error:



"Warning: Extra text '=75R' found.
Part: T1"

At this point, I'd just like to know if Micro-Cap is broken, or I'm missing something. Thanks to anyone who can help.

Well, we bought two of them and both has the same fatal for sound error: instead of -12V analog supply for PCM58 there's only -5V. It still works but completely out of parameters. You can easily check your KIT for this BAG - just compare resistors value near 3xLM317 stabilizers and if they all the same ( blue-white-black-black = 690 oHm and red-red-black-black= 220 ohm) then you are in 🙂 ! Or just check U on pins 9 or 20 of PCM58. Please, note that LM317 is POSITIVE stabilizer but in spite of this it is in NEGATIVE configuration (on attached picture there's stabiliser on right side of board just near the 3300uF Kenwood (Elna) capacitor). All you have to do is to change resistores value: 690 ohm on 1,3 kOm and 220 ohm on 150 ohm (1%) and you will be suprised 🙂 !
Also this DAC has no deemphases filter witch means that some old CD's will reproduce overtuned high frequency noise. I will make passive filter later and let you know.

Hey guys/gals I have an old Philips mini Hi-fi system that I want to capture the EQ curves from. The reason is because the original speakers sound great with the "DSP" applied to them but when I run the speakers through a regular amp they sound not great. The audio processing board uses a TDA7437 which uses an I^2C buss for commands to set the the Bass Mid, and Treb levels. What is the best way to do this ? Read the digital signal and get the Bass Mid and Treb level commands, or tap the output line level signal coming out of the audio processing board? And then what How do I inject a signal and see what is happening to it in terms of EQ?
Links
https://www.google.com/url?sa=t&rct...e-Manual.pdf&usg=AOvVaw2l4WvtwncByukmTfOb0xDk


TDA7437 PROCESSOR Datasheet pdf - AUDIO PROCESSOR. Equivalent, Catalog


Any info would be a great help

Thanks

Julian A Ayala

Was gifted a JL 500/1 monoblock amp. Once wired up, unit powers on but has 0 output (verified 0V AC, with headunit at 75% volume playing a 50hz test tone). Also tested another amp with no issues. I pulled the back cover and only visible damage is to the Q611 transistor.

Does anybody know of this is a common problem for these amps and if it’s worth the time investment to repair? Unit is probably 15 years old, but has sentimental value so I’d like to keep it alive if possible.

This is my first attempt at amp repair so I’d likely invest in the repair guide by Perry and buy some equipment to do it right, but not sure if I’m getting in over my head here. Have an ME degree and work in the aerospace field as an engineer, I’m fairly confident I can handle the work, but not sure if it’ll run into surprises along the way. Any advice is greatly appreciated on first steps.

At supposedly 146 lbs you wouldn't want to ship it too far but nonetheless. It works. A good project for an avid DIYer?

Regards,
Dan 😱


Tentatively Sold. Mark Levinson 333 Power Amplifier. $1,000 firm. May need some work Dealer Ad - Canuck Audio Mart

looking to build a 450v power supply. has to supply 230mA for 2x kt120 and 2x el84.

so looking at a 400-0-400 325mA transformer, then one CLCLC for both KT120's of 20uF, 2H 18ohm, 40uF, 5H 60ohm, 60uF.

The el84's will be powered by a RC of 1K and 20uF tapped off the last 60uf in the PS.

Sim'd it in PSUD and got 470v for KT120's and 440v for the el84's.

Thoughts?

Vintage Triangle T17FL2

It is a 7" bicone full-range speakers from mid-late 80s (I think I bought them in 1988-89) made in France by Triangle. They were considered premium speakers at that time, and it was difficult to find/afford anything else in that field for me, as I was a student...😱







It has been used in TQWT and in Bass-Reflex - this is the way I installed mine, because of a lack of space for TQWT... It's a low tuning, over-damped, fully stuffed one :

Vb=32L
Sv=50.3cm2
LV=32cm
Fb=38Hz
n=3.2
F3=70Hz, F6=55Hz, F10=40Hz





The T17FL2 was known to have a "coquetterie" in the 1KHz-10Khz area, that is to say an increase of level of 4-5dB, making him very present (see axis response curve above)... It's very charming at first, but becoming tiring in the long run : that's why I didn't used them too much.

Nearly 30 years after - never too late - I decided to correct that issue by experimenting the principle of a Baffle Step Compensation crossover... Not trivial for a full-range speaker ! 😕

OK - so suddenly, I discovered hot water... 😱 😀

I made many listening on different musical programs, at different loudness :



And finally came to this compensation circuit :



Where the coil and the resistor readjusts the level of the 1-10KHz range, and the capacitor enhances the upper treble over 10KHz.

Later on, I slightly increased the cap value and played the Audiophile Mojo by adding a silver mica capacitor 🙄



Those Black Boxes do their job very well : now the extra-presence is tamed and balanced with the rest of the audio spectrum, and upper treble range is here and fine.

You would have told me this 30 years ago, I would have been instictively very dubious, finding this truly irrational ! 😛

But it's me, OK ? 😀

A+!

Hello, I have from last year this cheap preamp board:

Buffer 6N11/6DJ8 Tube SRPP Preamplifier Headphone Amplifier Board Preamp PCB DIY 699917213049 | eBay

Since I'm interested to a circuit possibly with a lower Z out (maybe good for driving later an amp stage or so), I wonder if it's possibile to modify it simply for a mu-follower circuit, I was thinking to something like this schematic here

As a kid I was entranced by the idea of the Infinity Reference Standard. It was, of course, a 4 tower system, comprised of 2 subwoofer towers, and 2 mid/tweeter arrays.

I'm curious about two things.

Is there a benefit to subwoofers as line arrays? Besides the additional surface area? Do line array 12" drivers have a decided advantage in room mode management? Lets skip the usual smaller = better argument for this conversation please. 🙂

Secondly, as I recall, these were early servo controlled subs. In addition to limiting the distortion of the drivers could these have acted as active bass traps?

Does someone have a list of preferred mods for this amp?

For sale two pairs and one separate 01a tube in Nos condition.I buy this more than a year ago to build triode tube preamp,but I build it first with Y10 triodes and just stay buy this option becouse I have no time to try another tubes abd options.So I have now this superb tubes for sale.Price per pair is 60euro plus shipping inside EU.For one tube in the picture the price is 30 euro plus shipping.I payed a year ago with shipping and taxes from Usa more than100 eu for a pair.Plese if someone have interest send a message.All tubes have no ratles and firm bases.For info about triode preamps with this tubes look under Bartola/Ale Moglia in internet.