Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › The Stax thread (New)
New Posts  All Forums:Forum Nav:

The Stax thread (New) - Page 1579  

post #23671 of 24765
Originally Posted by EveTan View Post

does it.... requires soldering wires together? How does it connect? (I probably should take a look at the back of my speaker amp for the answer... but... it's a pain to take out)

 

Nah, the speaker amp will have those screw down terminals for the bare wire.

post #23672 of 24765

Bwaaaaa-Ha-Ha-Ha! Bare wires from Hell! Yup - that's how they used to do it...

 

Get a real stat amp. No bare wires. Sounds better too.

The old trafo boxes are a poor man's compromise these days.

As well are the six pin Lambdas that go with them.

post #23673 of 24765
Quote:
Originally Posted by deadlylover View Post

 

Nah, the speaker amp will have those screw down terminals for the bare wire.

Oh that's reassuring. Thanks.

post #23674 of 24765
Quote:
Originally Posted by livewire View Post

Bwaaaaa-Ha-Ha-Ha! Bare wires from Hell! Yup - that's how they used to do it...

 

Get a real stat amp. No bare wires. Sounds better too.

The old trafo boxes are a poor man's compromise these days.

As well are the six pin Lambdas that go with them.

So what would you recommend for a not "poor man's compromise" but not that wallet breaking? 

 

Value would be nice too.

post #23675 of 24765
Quote:
Originally Posted by EveTan View Post

So what would you recommend for a not "poor man's compromise" but not that wallet breaking? 

 

Value would be nice too.

 

Depends on what one considers "wallet breaking".

For around $700 (maybe a little less) a Stax SRS-2170 System

or the Koss ESP-950 System.

 

For about $1300, the Stax 407 with a SRM-323 amp.

 

Those are approximate prices for contemporary stat setups. (new)

One could do better if bought used.

post #23676 of 24765
Quote:
Originally Posted by livewire View Post

 

Depends on what one considers "wallet breaking".

For around $700 (maybe a little less) a Stax SRS-2170 System

or the Koss ESP-950 System.

 

 

You'd prefer the 207 over the Lambda normal bias?

post #23677 of 24765

Definitely.

 

I am a treble-head tho.

FWIW, the Stax expert Spritzer likes it too.

I own all three of the mid-fi stats that I just mentioned.

The Koss is tilted more torwards the midrange, the Stax 407 is sublime. Great balance.

 

I am sorry - as much as I would like to own a SR-009, it is a wallet breaker for me.frown.gif

post #23678 of 24765
Quote:
Originally Posted by livewire View Post

Definitely.

 

I am a treble-head tho.

FWIW, the Stax expert Spritzer likes it too.

I own all three of the mid-fi stats that I just mentioned.

The Koss is tilted more torwards the midrange, the Stax 407 is sublime. Great balance.

 

I am sorry - as much as I would like to own a SR-009, it is a wallet breaker for me.frown.gif

Ah, a fellow treble head. :)

 

Well, I'll prob get the 2050 tomorrow from the PO. I guess I'll try for a Lambda Signature instead of the normal bias.

post #23679 of 24765
Ill be joining the stax team soon enough! I'm buying GeorgeP's old KGSSHV off him since he finished his DIY T2. I got my deposit in for a pair of Sr-009s at price Japan to get in line, and I ordered a pair of Sr-307s from them as we'll to use while I wait for the 009s. I know I couldn't bare having an amazing electrostat amp sitting on my desk with no headphones to use with it
post #23680 of 24765
Quote:
Originally Posted by shipsupt View Post

Not sure about the ". ct ?"

 

Any other markings, colored bands?

It's black in colour, bluish text and single band on the polarity side of the diode. See picture below.

Quote:
Originally Posted by duncan1 View Post

  Nearest I can find to "CT" is "color television" [for the use of] Germanium usually have a much higher frequency band width and speed than standard silicon diodes other than the ones like Shipsupt has said --Shottky  Diodes. So its possible that was what it was indicated for [very early use].  

Yeah I couldn't find anything online about the .cT extension after 309, but I did run into some 80v or so rated Toshiba diodes with the 309 extension online. What else is a bit suspicious is the legs on each of the 4 diodes look crispy burnt, but not completely black. I tried scratching it with the end of a Philips head screwdriver to see if it just dust and burnt flux or so and it doesn't come quite easily.

 

Anyway here's some pictures (used sticky tape to stick them on so picked up some velcro dust and hair fibers):
 

 

 

 

 

 

 

 

 

 

Quote:
Originally Posted by spritzer View Post

One small flaw to all of this... there is only one PSU for both channels.  Two caps stacked on top of the other, or one cap gives 315VDC and the other one on top of it also gives that too but since it's "ground" is 315V the output voltage is 630V. 

 

No chance that there are Germanium diodes in this amp.  The one I restored had bog standard Si from Toshiba which I replaced with something similar.  Even the Stax amps from the late 60's has Si everything. 

 

The problem is clearly in the amp section so look there.  Measure between the channels but a simple test of the output voltages will confirm that it at play here. 

Ok, so one PS for both channels. From what you're saying is that the two ELNA caps where one measures 315v(+) - 0vdc(-) and the other one (closest to the 600v B+ white wire) measures 630vdc (+) - 315vdc (-) is normal?

 

I will measure all points once the replacement DMM comes in, but now that you've mentioned that something is possibly wrong with the amp section this is not good because this is where the 8 in total Sanken transistors are located at, since original replacements are near impossible to find are there any modern in production substitutes that will work in it's place?

post #23681 of 24765

The blue die is a dead give away for a Toshiba diode.  They used 1S1830 in the SRA-12S which is very similar so 1N4007 will be fine. 

 

That is how the PSU works, only two ways to generate 630VDC with electrolytic caps of this voltage rating and this is the cheap way. 

 

You can always find subs but they will not be the same form factor or have the same pinouts. 

post #23682 of 24765

Ok thanks for the clearup. I'm guessing the diodes is fine then because the different measurements from the caps put me off a bit when measured. 

 

Since there is not much info online how does one find or use some sort of website to find substitutes for:

 

4 x Sanken 2SC1828 -

 

4 x Sanken 2SD594 transistors?

 

There is some info on the 2SC1828 but not a single bit on the 2SD594.

post #23683 of 24765

DefQon- 2SC1828--[in my German equivalent book]= BUV36/BUX84/85/ 2SC3149/2SC3352.-----2SD594-=BSW51/52BSY58/2N2218/19. Remember unlike tubes where you can "get away" with putting a different tube into the tube socket[within reason] Solid state active devices all have some difference-manufacturer to manufacturer . But those mentioned should work okay.In large power amps [solid state] for loudspeakers you CANT get away with just "trying out" different  output devices SS[and I have built and repaired many] are TUNED to the circuit and the active devices that's why comp caps/local feedback caps are fitted. The better the amp the less comp caps required--means the engineer has spent some time rearranging the circuit and choosing quality active devices SUITED to the circuit being built. I still have my --SRD-7SB- bypassed the switch with solid core cable/ uprated some components. But don't use it now.That black deposit is old age forms on many components like that a type of oxidization.---I forgot to add indiscriminate changing of output devices without any checking if they are compatible   in many cases produces a VERY large high frequency    sine wave output running the output devices into "overdrive" blowing them all and usually taking out the drivers too!


Edited by duncan1 - 7/20/13 at 4:03am
post #23684 of 24765
Quote:
Originally Posted by duncan1 View Post

DefQon- 2SC1828--[in my German equivalent book]= BUV36/BUX84/85/ 2SC3149/2SC3352.-----2SD594-=BSW51/52BSY58/2N2218/19. Remember unlike tubes where you can "get away" with putting a different tube into the tube socket[within reason] Solid state active devices all have some difference-manufacturer to manufacturer . But those mentioned should work okay.In large power amps [solid state] for loudspeakers you CANT get away with just "trying out" different  output devices SS[and I have built and repaired many] are TUNED to the circuit and the active devices that's why comp caps/local feedback caps are fitted. The better the amp the less comp caps required--means the engineer has spent some time rearranging the circuit and choosing quality active devices SUITED to the circuit being built. I still have my --SRD-7SB- bypassed the switch with solid core cable/ uprated some components. But don't use it now.That black deposit is old age forms on many components like that a type of oxidization.

Thanks for that duncan. After just a brief few moments of google searching and rummaging around with RFQ's to various suppliers that may have some of the original Sanken ones. I've looked just for the 2SC1828 and 2SC594's in general without the Sanken prefix.

 

2SC1828 did not return any results besides this pdf file of another equivalent manufacturer of the same transistor type:

 

http://elcodis.com/parts/6019088/2SC1828.html#datasheet

 

Now searching onto the 2SC594's brought in a bit more light. Seem's there are current equivalents to this particular power transistor

 

Equivalent:

http://www.vetco.net/catalog/product_info.php?products_id=1902

 

And here is one ebay'er selling some NJS 2SC594's.

 

http://www.ebay.com.au/itm/2SC594-TRANSISTOR-NJS-SCARE-VINTAGE-NOS-AV-31-/110978312813

 

Really itching to just buy a few and try it out, since I assume the worst that can happen is smoked resistors, diodes and possibly blown transistors. I have replacement resistors and soon diodes to be ready at hand.

 

What I need is the original Sanken spec/technical sheets so I can compare the values/ratings besides just dropping in the same physical size/connector/pin out replacement. 

post #23685 of 24765

I tried--www.data sheet archive for Sanken but its mainly a on line equivalent book - DO NOT BUY from VETCO!!!- no manufacturer in their right mind would produce as long a list of equivalents as on that website must be a retailer.-Just scrolling through some ""equivalents" shows differences in bandwidth/gain /speed/ and capacitance/etc some would definitely make your amp unstable. Quality equivalent book companies have maybe 4 or five -CLOSE equivalents.Elcodis is very near but leaves out bandwidth and speed and check gain.That's why I bought German equivalent books- The German mind  in engineering is "right on the money" they "get it right" its like a religion for them it would be a "disgrace" if they got any type of engineering wrong.---2SC594--= in German book=60V- 0.2A-0.75W-30/280NS[that means its for high frequency use] so in its day it was and still is a GOOD quality component--remember equivalents might not have the same speed.In my English equivalents book--2SC594=the SAME as the German book BUT beware after the transistor number there are letters -R-Y-O--do NOT buy these as these have LOWER gain than the basic 594 --- 2SC1828=800V-1A-40W-7MHZ[German book]-English book-=same except-4MHZ bandwidth-bias-200MA .Still shocked at that company above. People post on this website to gain information and help. They arent helping anyone.Just trying to up the profit$$$.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: High-end Audio Forum
This thread is locked  
Head-Fi.org › Forums › Summit-Fi (High-End Audio) › High-end Audio Forum › The Stax thread (New)