Drake OT's for 100 Watts

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VelvetGeorge
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Drake OT's for 100 Watts

Post by VelvetGeorge » Thu Jun 22, 2006 10:32 pm

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.

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Flames1950
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Post by Flames1950 » Thu Jun 22, 2006 11:21 pm

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?
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Ot's

Post by Brian Wallace » Thu Jun 22, 2006 11:25 pm

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. ;)
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Post by Flames1950 » Thu Jun 22, 2006 11:31 pm

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!
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Re: Ot's

Post by VelvetGeorge » Thu Jun 22, 2006 11:59 pm

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.

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Post by Marshall Growl » Sat Apr 07, 2007 6:34 am

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?
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Re: Drake OT's for 100 Watts

Post by Ralle » Tue Dec 04, 2012 12:56 pm

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?

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Re: Drake OT's for 100 Watts

Post by Brian Wallace » Wed Dec 05, 2012 7:22 pm

The 132 has a 1.75k primary. That's what I think. :)
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Re: Drake OT's for 100 Watts

Post by neikeel » Thu Dec 06, 2012 7:19 am

Brian Wallace wrote:The 132 has a 1.75k primary. That's what I think. :)
What do you know about it Brian? :roll:

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!
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Re: Drake OT's for 100 Watts

Post by Brian Wallace » Sat Dec 08, 2012 10:02 am

Hey Neil,

The 1202-99 and 1209-3 are Drake copies of the C1998 and T2562 transformers.
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Re: Drake OT's for 100 Watts

Post by neikeel » Sat Dec 08, 2012 10:19 am

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?
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Re: Drake OT's for 100 Watts

Post by bill bokey » Sun Dec 09, 2012 9:23 am

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.

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Re: Drake OT's for 100 Watts

Post by neikeel » Sun Dec 09, 2012 12:11 pm

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 :wink:
Neil

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Re: Drake OT's for 100 Watts

Post by bill bokey » Mon Dec 10, 2012 7:34 am

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

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