Metropoulos Forum

Drake 100 watt output transformers:


11/65 1202-84 2" core 4K primary 8,16 and 100V taps


02/67 1202-119 2" core 1.75k primary 8,16 and 100V taps


06/67 1202-132 2" core 1.75k primary 4,8,16 taps



Also, the Dagnall C1998 seems to date to 11/67.

george

From the primary impedances only the 1202-84 is a KT66 tranny, right? The others are EL34?

I guess I was assuming your '66 was a KT66 amp....is it set up with EL34's right now?

Yes, the 1202-84 is the only KT66 OT but either tube will work just fine with these transformers, give it a shot and see what you think.

The C1998 is more of an August OT IMO.

Nah, I'll stick with the KT66's on your 1202-84 clone in my Super PA.......I'm just glad you used a four ohm tap instead of the 100V tap!

Brian Wallace wrote: The C1998 is more of an August OT IMO.

Really? I thought someone had confirmed that date with Dagnall. Of course, it's just what I heard- I can't back it up.

george

Is the transformer in the Marshall super 100JH specifically made around the kt-66 tube? Also, in this amp would one speaker jack put out 100 watts at 16 ohms on the selector? Or are you supposed to half it when using 1 cab?

I found a forum called Marshall Road House, and there's one guy ( moderator ) that says the Drake 1202-132 ot has a primary impedance at 2.2k...
Here's what he says:


Drake 784-103 (Primary: 8k ohm, Secondary: 8, 16 ohm, 100V line) JTM 45, JTM 45/100 (dual output transformers)

Drake 784-128 (Primary: 3,5k ohm, Secondary: 4, 8, 16 ohm, buried 100V winding) JMP 50

Drake 784-139 (Primary: 3,5k ohm, Secondary: 4, 8, 16 ohm) JMP 50

Drake 1202-84 (2" Stack, Primary: 4k ohm, Secondary: 8, 16 ohm, 100V line) JTM45/100

Drake 1202-119 (2" Stack, Primary: 1.75k ohm, Secondary: 8, 16 ohm, 100V line) JTM 100 (Black Flag) , JMP 100

Drake 1202-132 (2" Stack, Primary: 2.2k ohm, Secondary: 4, 8, 16 ohm) JTM 100 (Black Flag), JMP 100

Drake 1209-3 JMP 100 (2" stack, used on a few early 70s 100 watt amps)

Dagnall C1998 (1.5" Stack, paper bobbin, Primary: 1.75k ohm, Secondary: 4, 8, 16 ohm) JMP 100

Dagnall C2668 (1.5" Stack, nylon bobbin, Primary: 1.75k ohm, Secondary: 4, 8, 16 ohm) JMP 100

What do you guys think of this?

The 132 has a 1.75k primary. That's what I think.

Brian Wallace wrote:The 132 has a 1.75k primary. That's what I think.

What do you know about it Brian?

Whilst you are here my recollection of my old '71 JMP100 was the OT was 1 1/2" 1202-99

http://forum.metroamp.com/search.php?st ... l&start=45

and the 1209-3 is a 2" PT.

So I think your source (moderator?!) is less than reliable!

Hey Neil,

The 1202-99 and 1209-3 are Drake copies of the C1998 and T2562 transformers.

Yes that would fit.

I thought the Drake better than a 2668 or 2373 but still in same style as a 1 1/2" Dagnall, maybe a little more together?

Brian Wallace wrote:Hey Neil,

The 1202-99 and 1209-3 are Drake copies of the C1998 and T2562 transformers.

Glad to read that as I have a 1202-99 sitting on a shelf.
When I have a minute (or 60) I'll replace a Marstran C1998 with the Drake 1202-99 in my SL clone. Wonder if I'll hear an improvement.

bill bokey wrote:

Brian Wallace wrote:Hey Neil,

The 1202-99 and 1209-3 are Drake copies of the C1998 and T2562 transformers.

Glad to read that as I have a 1202-99 sitting on a shelf.
When I have a minute (or 60) I'll replace a Marstran C1998 with the Drake 1202-99 in my SL clone. Wonder if I'll hear an improvement.

Let us know

I will and I'll also record some before/after clips.

bill bokey wrote: ↑

Mon Dec 10, 2012 7:34 am

I will and I'll also record some before/after clips.

When? Still within this century?