The ultimate DIY? A Stax SRM-T2!

[chinsettawong]

Ceramic sockets are way cheaper than Teflon. 

[kevin gilmore]

and I do not think they will fit the board. Maybe the 8 pin sockets can be made to fit, but

not the 9 pin.

[iwik]

Yes the 9pin ones I got fit the board ok. I was just wondering if

they were that much inferior.

Les

[spritzer]

It really depends on the contacts and their quality.  I suspect they are the same as the teflon units so you should be fine.  That's assuming you are referring to something like this:

 

http://www.ebay.com/itm/1pc-9pin-Ceramic-Tube-Socket-Machine-Made-Gold-Pin-for-12AX7-EL84-6922-New-/130674502828?pt=Vintage_Electronics_R2&hash=item1e6cceacac

[iwik]

Birgir,

Yes they are that type.

Les

[kevin gilmore]

looks like the same pins as the teflon sockets, so if that is what you got

it should be ok for both sockets

[iwik]

Thanks Guys,

Getting closer to build start.

Les

[mortal_fiend]

After looking at quotes for individual boards, I'm beginning to understand the concept of a group buy.  Any chance anyone has a spare amp board or power board they'd be willing to sell?  Pm me if you're willing to sell.

[spritzer]

I will be ordering amp boards soon but I'll need to make a new version first.  It needs some changes...

[luvdunhill]

I will be ordering amp boards soon but I'll need to make a new version first. It needs some changes...

Perhaps add a bit more rail capacitance and holes next to the power supply pads for probe points. I would also space the test point locations out a bit. Yeah there are probably lots of little things here and there.

[mortal_fiend]

@spritzer

Have you decided which materials/stats you'll be using for this go-around (FR-4 vs CLTE, .062" vs .125", ENIG vs ENEPIG vs whatever,  2 oz vs 4 oz, # of layers, etc.), or is it that thinking too far in advance?

[spritzer]

FR4 and 4oz like the original test boards.  Only two layers on all of our amps... 

 

Perhaps add a bit more rail capacitance and holes next to the power supply pads for probe points. I would also space the test point locations out a bit. Yeah there are probably lots of little things here and there.

 

That's the general idea, fix those small issues such as a proper way to do the test pads, redo the input a bit to suit my particular needs (hello loopouts) and the like. 

[niner]

Had anyone received the chassis from Lil Knight yet?  Can you share a pic or 2?

[mortal_fiend]

I guess not?

[niner]

I guess not?

Guess not.  It will be nice to get an update from Tran.

[jgazal]

Just in case.

 

http://www.tempoelectric.com/azl_sale.htm

 

this guy has some interesting things (mostly audio related) for sale at fairly low price... definitely worth checking out. 

 

 

 

Audio Sale of Items From the Estate of Dr. Arthur Loesch (Part 2)

All prices + shipping from Troy, NY 12180

Updated April 17, 2014 (...)

TEST & OTHER EQUIPMENT:

 

382

(2) Acopian Regulated Power Supplies

Model B35GT50. Output: 35V @ 50mA

50.00

Each

 

383

Acopian Dual Output Power Supply

Model 150GT10D-150GT10D. Output 150 VDC x 2 sections @ 0.1A

95.00

 

384

Altec Lansing Model 536A Power Supply

Output: 20VDC @ 400mA

20.00

 

385

Cenco DC Amp Meter

0-5 Amp Range

10.00

 

386

Eico 379 Sine/Square Wave Generator

25.00

 

387

Eico 1078 Variable AC Supply

With Volt/Amp Meter

55.00

 

388

(2) GenRad 1201-C Regulated Power Supplies

Includes Manual. 240V-340V Regulated mono power supplies, perfect for building an Arthur Loesch-style phono preamp.

75.00

Each

 

389

(2) GenRad 1206-B Amplifiers

Includes schematics

20.00

Each

 

391

GenRad 1217-C Pulse Generator

Includes 1203-A Power Supply and Manual for the 1217-C

40.00

 

392

GenRad Model 1900 Wave Analyzer

VG+. Presumed to be in good working condition.

60 lbs.

Net Weight,
Pick-up preferred

75.00

 

393

GenRad Variac

Variable AC Transformer; 0-130V AC Range

75.00

 

395

Heathkit IM-38 VTVM Vacuum Tube Voltmeter

Includes a Decibel Meter scale

25.00

 

397

HP 450A Amplifier

45.00

 

399

Radio Shack 42-3019 Sound Level Meter

Includes soft case and original manual.

10.00

 

400

Rex 423 4-Range Rheostat

35.00

 

401

Simpson 2785 Impedance Bridge

Manual included.

35.00

 

402

Simpson 1699 Milliohm Meter

40.00

 

403

Simpson Model 885 Sound Level Meter

Includes the calibratiion tool, case, and original manuals.

75.00

 

404

Staco High Voltage DC Power Supply

40.00

 

406

Tektronix 575 Transistor Curve Tracer

VG+. Presumed to be in good working condition.

70 lbs.

Net Weight,
Pick-up preferred

75.00

Edited April 17, 2014 by jgazal

[luvdunhill]

if you look at the insides of the original, the 22k resistor was

mounted on the backside about .5 inch from the board so that

you could put clipleads on it to adjust.

Kevin/Birgir: do you have a pic to confirm this? Sure it's not the 62K resistor? I suppose either could work, just curious.

Also any chance you know the voltage across R73 in the original? It's the 6.2K resistor at the base of the Darlington in the servo...

[luvdunhill]

Looks like red-red-black-red-brown = 22K 1%. Ok. Still interested in other question though...

[spritzer]

We might have measured it at some time but this was 5 years ago. 

[kevin gilmore]

A few people have asked about the angle brackets.

But I don't have any more.

 

But the don needs some.

 

So I will make some more. If anyone is interested let me know.

Probably going to be about $140 for the set of 4 given what the

price was, and what the new hourly rate for the machine is.

Plus shipping.

Will get an exact price on Monday.

 

These will be for the original boards, not the shrunk one I did for lil-knight.

Edited April 24, 2014 by kevin gilmore

[nopants]

seems like a neat alternative to the lil knight group buy

[kevin gilmore]

this is just the angle brackets, and for the boards that are 16 inches long.

 

lil-knight has a board layout that is 15.65 inches long that fits his chassis.

 

so the brackets I will be making are for the 16 inch board.

 

will see about the other version later.

 

so far 4 sets are spoken for.

[nopants]

I understood the distinction, I was just thinking that if we spun our own T2 boards (the older version) this would allow some flexibility in heatsink/case choices

[spritzer]

The current board just about fits a Modushop Pesante Dissipante chassis...

[luvdunhill]

If it's not tied to the original case, I would try to get more of the device case on the flange. IMHO the old design there is a 1/8" or so of the case off the edge.