Hammond 1650N opt

[ontariomaximus]

I have 4 or 5 of these things. Its an OVERSIZE 60W transformer (at least as big as a Fender Twin) and has a 4300 primary. Anyone see a problem using an 8ohm load on the 16 ohm tap with 4 x 6L6's (2150 ohm primary Z)? If so, what are people using for 100w opt trannies? I'd use a Fender Twin but it only has a 4 ohm output.

[John_P_WI]

I can't answer exactly, but remember the 60 watts is a full bandwidth rating, something you are not requiring if it is for a guitar.

From past experience, I have used the 1650N (mid-90's construction) in a nearly class A amp using two 6l6 tubes and the 1650N didn't even flinch in the high current draw. I still run that "plexi" today.

IIRC, the "newer" 1650Ns have a different secondary wiring scheme that make them a pain to wire an impedence selector to???

Good luck,

John

[RHGraham]

Hammond now has an "easy wire" version also.

[Structo]

Yes I would like to understand this better as well.

I was browsing the Hammond site yesterday and I was looking at the 1600 and 1700 series with the multi tap secondaries.

I don't understand how you would wire it to, say a Hoffman impedance switch, because it appears that you have to connect several wires together on these new transformers. These are the "Easy Wire" push-pull ultra linear xformers. What does ultra linear mean to me for a guitar amp?

I am thinking about putting a bigger iron OT in my D'Lite 44 but I'm not sure which OT to use. I want it to have 4,8, 16 secondary taps so I can use my impedance switch.

[img:300:183]http://www.hammondmfg.com/pp1.GIF[/img]

[img:200:128]http://www.hammondmfg.com/sec1.gif[/img]

[img:200:126]http://www.hammondmfg.com/sec3.gif[/img]

[img:200:129]http://www.hammondmfg.com/sec2.gif[/img]

[ontariomaximus]

I have only used the 1650N with separate jacks for the 8 and 4 ohm connections and passing on the 16 ohm. Having all 3 would require some PITA switching

[John_P_WI]

What power Xformer are you using? I looked at the current rating of the 1650N and it is 330 ma continuous. If your power transformer is around this or less, you are good to go. I have matched up the 1650N to the 272JX in the past, it won't give you the power of the 100 watt Xformer, but it will give you the tone of 100 watts due to the added 2 power tubes.

John

[mlp-mx6]

AES/CE Dist sells a rotary switch pre-wired for all the Hammond weird-o switching options. Works fine, seems a little light in the current capacity. I have used it on a couple 2-6V6 amps I've build and it's fine. I probably would not use it on a 100W amp, though. Just doesn't seem stout enough - but what do I know?

[Structo]

Do you have a part number for the ASE switch?

I searched the site but could not find it.

Thanks.

Never mind I found it.

It is under the Hammond transformer list at the bottom.

The switch itself looks a lot like the switch that the D'Lite kit comes with.

If it is the same, you can wire in the multiple poles to increase current handling.

[mlp-mx6]

You may be able to parallelize the switch, I do not know. However, I can tell you that there is a good bit if jumpering already on the switch, so I also cannot guarantee that there are unused sections.

What I *can* tell you is that the holes to solder to are quite small relative to the OT secondary wires, so it was a bit of a pain to get the wires in place.

[Structo]

Also can anybody explain the ultra linear terminology to me?

What is it and is it desired on a guitar amp?

[jelle]

http://www.webace.com.au/~electron/tubes/ul.html

This is a nice read and provided me with some pretty relevant insight to powerstages in general.

Have fun,

Jelle

[Structo]

So basically you have to use the 40% screen taps to make it linear?


Here's the deal.

I have a Brown Note D'Lite that I have modded up the kazoo.

It has the dual impedance primaries with 4,8, 16 secondaries.

I don't care about the primaries since this is going to stay a 6L6 amp.

I am thinking I want a bigger iron OT on this but have a hard time sifting through the myriad of transformers out there.

I've looked at the Fender replacement trannys and most are limited by the output impedance.

The tranny that is in the amp now is a custom Heyboer ( I think).
But it is pretty small physically.

So what OT are you guys using for the two 6L6 amps?

Like I said I would like to preserve the 4,8, 16 taps for the impedance switch.

[Structo]

Anybody have an OT recommendation for me?

This is a 2x6L6 D'Lite.

I want 4,8, 16 ohm secondaries with a 4000 ohm primary.

[greiswig]

Anybody have an OT recommendation for me?

This is a 2x6L6 D'Lite.

I want 4,8, 16 ohm secondaries with a 4000 ohm primary.

Talk to Funk. If you get the one I have, you'd even have a 32 ohm secondary you could use if you like!

[moj067]

Structo-Angela instruments has a Fender Prosonic Transformer, but I'm not sure about the actual specs, the price is nice at least.
I think these are Jensen sourced.
Just throwing out options.