6V6 Push-Pull output transformer

[Mars Amp Repair]

Hey folks,
I'm trying to source an output transformer for a pair of 6V6 in Push-Pull config. It needs to be 20Watts and have 4-16ohm taps. Hammond is trying to tell me that their 1645A should do the job, but the primary impeadance is 5K no what you'd expect of 8K for 6V6 Push-Pull config.
I don't have a lot of experience in this but it seems to me that the mismatch between 8K and 5K would be significant.
Hammond does not have another 20Watt xformer that has prim imp of 8K.
This is for the Divided by 13 amp I posted about recently and Fred there says the CO that mfg his xformers will not have any production on them until at least feb 23.
What other companies can I search.
Any ideas on another source. I tried Triad & can't seem to get anywhere there.
As always thanx...glen

[g1]

Sounds like just your basic Deluxe Reverb OT with more taps? 6K6 primary would be closer?
Something like this: https://shop.amppartsdirect.com/prod...laced-40-18087

Or Hammond 1760H ?

[Tom Phillips]

How about a Hammond 1608A. It's officially listed as a 10W unit but that's for ±1dB over 30Hz - 30kHz. It's physically larger than a typical 20W guitar amp OT. There also the Hammond 1650E which is rated at 15W for ±1dB over 30Hz - 30kHz. My experience is that they will often do twice the rated power in guitar amp circuits. Maybe Hammond will have some additional info or comments.

[Helmholtz]

5k looks low for 2x6V6s. Would be tough on the plates.

Fender used a 6.6k OT with the Deluxe Rev (see Hammond 1760H), probably because it gives a little more power compared to 8k.

Or consider Hammond type 1750PA (8.4k/18W).

What is B+ and actual power output of the amp?

What was wrong with the original OT?

Edit: Forgot to post this reply about 30 minutes ago.

[mozz]

Musical power supplies on eBAY.

[Chuck H]

I have some experience with the 1608. I haven't had the pleasure of using the 1608A yet. The standard 1608 (with the convoluted secondary options) is a fantastic transformer that will easily handle a 20W guitar amp. A very long time ago here an old member (Shea) was making Marshall 18W clones and winning some local tone competitions with them. I have that transformer in my own personal amp which is a prototype for some amps I built to present at the 2009 NAMM show for someone who's name you would recognize. Those amps had custom Hyboer iron. But when I had the Hyboers made I told them what transformer I was using and that I wanted something very similar. So I've heard the 1608 and it's Hyboer equivalent side by side. The 1608 sounds better.

JM2C and a vote for the Hammond iron.

[Chuck H]

From an earlier thread about what I assume is the same amp:

Hello all,More on this Divided by 13 amp. I've got the output xformer replaced and all works now.

So you're replacing this OT a second time then.?. Did you or the customer notice something wrong with whatever replacement you have in there?

[Chuck H]

FWIW Mercury does offer a 20W 8k primary OT for 6V6's. One hell of a stack of iron on it. Does this look like the one you need? It wouldn't surprise me if it were almost the same unit. Almost twice the price of the Hammond (also a big stack of iron), but that's not surprising.

https://www.mercurymagnetics.com/product/lan-o20-8k-2/

[Mars Amp Repair]

From an earlier thread about what I assume is the same amp:

So you're replacing this OT a second time then.?. Did you or the customer notice something wrong with whatever replacement you have in there?

Actually, the Hammond 1645 xformer I received from CE was defective along with having weird secondary connections for only one impedance at a time.

The xformer has 2 independent secondary windings that have to be interconnected to produce only ONE impedance at a time.
It was actually defective in that with no connection between the 2 secondaries, there as a very low resistance (probably a short) between the 2 independent secondaries.

Fortunately, CE offered a refund and not a mandatory replacement of the same xformer. This is why I'm looking for the one that you linked me to.
BTW it took a bit of explaining to get the rep at Hammond to understand what the issue is that I was having with the xformer. That surprised me.

He did concede that although they list what tube compliment the xformers will accommodate, somewhere he claims they have listed a disclaimer that the information they list is not necesarily accurate. Nice, huh.
It was really my bahd for not noticing the 1645 was a 5K primary & not an 8K. I apparently foolishly just accepted their listing that if was good for a pair of 6V6's. He claimed that there are so many different configurations for a pair of 6V6's that the 1645 with a 5K primary would accommodate one of them!

Thanx for the link to the Merc Mag LAN-O20-8K. That I'm not going to mess with Hammond for this as the Merc Mag looks like exactly what I need and really is jore appropriate for the Boutique (using term loosly) amp.
glen...

[Chuck H]

Glad I could help. That transformer is STUPID expensive. But I agree that it's in keeping with the spirit of the amp at hand.

As to the Hammond wiring... It's not hard to get 4 and 16 ohm impedance options from a DPDT switch even from the standard 1608. The 1608A has the tapped secondary to make impedance selection easier for builders that want the standard 4/8/16 option. My own amp has the standard 1608 and 4/8 option for impedance (I think, I can't remember since I only use the 8 ohm) using a DPDT. I'm sorry you had a bad experience with the Hammond product. And I haven't tried any of the "Easy wire secondary" offerings yet but I'll stand by my endorsement for the standard 1608. It sounds great and it's bulletproof. I've accidentally done things to it a couple of times that might have damaged a more timid OT.

[pdf64]

How about Hammond’s JTM45 type OT, 7k3, may be pricey, but should be cheaper than almost any MM, and should have good interleaving https://www.hammfg.com/files/parts/pdf/1750Q.pdf

[Mars Amp Repair]

How about Hammond’s JTM45 type OT, 7k3, may be pricey, but should be cheaper than almost any MM, and should have good interleaving https://www.hammfg.com/files/parts/pdf/1750Q.pdf

Looks like the Prim impedance is 7371K. I guess that would be close enough to 8K to work. Wonder why such a weird input impedance? Thanx, glen

[Helmholtz]

Wonder why such a weird input impedance?

It's probably a replica of a JTM45 RI OT (Drake 784-389). Original measures around 7.4k. Has simple interleaving (pri-sec-pri-sec).