Vintage amp restoration and Beyond

[GoldenVulture]

I got given a vintage Aus. amp some ten years or so ago. An Eminar 100 watt head
it's very similar to one posted here - http://www.ozvalveamps.org/eminar.htm - scroll down to P606.
It's a bit of a beast based on the JMP800's.
Four 6l6's [ or EL34's ]
I repopulated most of the capacitors and resistors with new [ nos in some cases ] ones. It has new valve sockets for the output valves
It originally had slider controls in stead of pots and they were fucked. The chassis has all the pot holes too so I decided to  put in pots instead. That's where I'm up to.

It got put aside and forgotten about a year or two ago but Karps Windsor thread reminded me of it so I got it out
to see where I'd got to.
 I Just need to do the pots and clean up a bit of wiring and I'm ready to turn it on. I don't know why I didn't get back to it sooner. Depending on what it sounds like it is a potential candidate to mod like the windsor to a full on 2203 conversion, poweramp and preamp. It's got some really solid transformers in it which Eminar included in their version of "The PiG " Marshall Major so it can potentially be beefed up with KT88's. I've got a 400 Watt quad box so why not

Phone pics sorry.

[karpathion]

Hell yeah! I'd be scared of that amp with KT88's. That one will be a breeze to mod, too. Have fun!

[GoldenVulture]

Yes ,tag boards and P-P wiring makes things easy to hack around.

[karpathion]

I've never seen an amp with slider controls like that before. A simple finished wooden plate would cover those just fine and look tastey. 

Do you have a schematic for that one? I'd like to have a look and see how it differs from what I've been working on.

Nevermind, I found them.

[GoldenVulture]

- http://www.ozvalveamps.org/eminar.htm - scroll down to P606. - there's some circuit links in the post, which is easy to miss.
It's layout is almost the same as a 2203 power amp section with slightly different values on some components.
It'd be suited to the Kerry King KT88 mod. which is very close to your Windsor mod.

The Major which uses four KT88's too, outputs 200 watts and uses a different O.P.transformer whereas the kK mod uses pretty much the same as the standard 2203. The KK mod pushes the 2203 to around 150/160 watts which must put a bit of pressure on th O.P.T.

[karpathion]

The tone stacks in the middle of the preamp gain stages are interesting. With all the tube sockets already there, a 2203 preamp is nothing to wire in with that setup.

The power section really is close isn't it? That setup on the PI is almost identical. You can already see how its layed out on your terminals too. Would only take a few minutes to change all that over. 

I need to look at, The Pigs, schematic too. It can't be that much to run kt88's. Probably just a few resistor changes, and a cap or two.

Does having different primary voltages than me change the values in the amp, or do the transformers give you the same secondaries I get?

[GoldenVulture]

It makes no diff. having the higher primary voltage. The secondaries are the same. A lot of Marshals come with a switchable primary from 110 to 220~240 volts. [ made in the U.K.]

Running KT88's draws higher current so you'd need to make sure your P.S. could deliver.
Any idea what the Ohms are on the valve [ primary ] side of the O.P.T. of the Windsor ?

[GoldenVulture]

The 2203 Kerry King mod using KT88's.

- https://drive.google.com/file/d/0B9WgrAT...rp=1&hl=en -

- https://drive.google.com/file/d/0B9WgrAT...rp=1&hl=en -

[karpathion]

I can check it when I get home later.

Are you calling it a Princeton because of the 6l6s? I've seem someone else say that too.

[GoldenVulture]

I can check it when I get home later.

Are you calling it a Princeton because of the 6l6s? I've seem someone else say that too.

Nope, sorry... too stoned or something; I meant the Windsor

It's 4:40 AM here, I should go to bed.