Is this original Dynaco Transformer? Help me identify.

[sparks]

Dynaco
454565
ZT0203

....

Also the power transformer is labeled "Dynaco 464774, 5497051" ?

These doesn't look to be recently installed as lot of dust has settled on the base and the wires. All tubes were labeled dynaco, that makes me think these tranny's also are original. Comments pls.?

Vinay

Yep - these are the original Dynaco transformers. These are the later ones with plastic covered leads and are Japanese manufacture. Probably late 60's. The output is 454565 (aka Z-565) and the power is 464774 (aka PA-774). These will work great! Good find,

Shannon

[Guest]

Thanks Shannon. I will take the transformers out. The remains will go back on ebay.

I am waiting for your EICLONE pcb, will order both (Stereo 35 & Eiclone PCB) once EICLONE PCB's are available.

Vinay

[EWBrown]

THose are the same style trannies that the SCA-35 I got on E-bay a while ago had, with the plastic (not cloth covered) leads.

On that unit, I removed all the original circuit boards, replaced the PA boards with aftermarket fiberglass ST-35 replacements (Also from Ebay)
and essentially turned it into an ST-35. Only difference, is that I left in the volume and balance controls. The preamp, selector switch and tone controls and "filter" switches were either totally removed or just disconnected. I replaced the preamp board with a home made filter cap board, to give additional filtering and capacitance.

I would have stuck with the original SCA-35 PA boards (with the 7199) but they were pretty well toasted to a dark brown.

I have this "ST35+" in the lab at work, fed by an older but still good Rotel CD855 CD player. and it feeds two RS "Optimus" speakers, overall it souinds pretty decent.

Those new model trannies will work fine with the DIY35 board.

/ed brown in NH

[Shannon Parks]

Please confirm if the DIY35 can be used with 4 ohm speakers?

People do run 4-ohm loads on these transformers. But the load operation changes and power will be lost. Nor I can't say what the bandwidth changes and distortion characteristics would end up like. Maybe you should just keep it in one piece and try it out on the Lowthers once you get them.

Shannon

[Shannon Parks]

FYI, I was skimming through Audioasylum and found this:

http://www.audioasylum.com/forums/tubed ... 28018.html

Shannon

[EWBrown]

I just got another pair of old E-bay bargain Z565s ready to use. The original leads were cut fairly short, 2" or less, so I added 8" long wires and used heatshrink tubing to cover the solder connections. These trannies were cheap just because they were trimmed so short.

Just a wild thought, may be totally crazy, would 4 ohm speakers work if connected between the 8 and 16 ohm output connections? Seeing as impedance is a square of the ratio of number of turns, perhaps this sould be a closer match to 4 ohms. I have found that sometimes these "harebrained" schemes work quite well.

For my own use, I just use the 8 ohm output only, the 16 ohm goes straight to the NFB connection on the PCB. If I use HWTs or other OPTs with a 4 ohm tap, I'll bring it out, but usually don't bother bringing out the 16 ohms, as I don't have any 16 ohm speakers.

/ed brown

[EWBrown]

Worth a look, they address the mystical Z-565 OPTs here:

http://www.tnt-audio.com/ampli/dynaco-st35_e.html

/ed brown