Upgrade PT & OT

[runout1]

I purchased a "cheaper" 36 watt kit.
Truthfully it was all the budget would allow.
In addition I am a total newb!! My question is
what are some good moderately priced pt & ot's.
Can I beef them up a bit and go with 45watt pt &
ot? If not what some really beefy ones that I can use?
thanks for all the help thus far!!!!

[rjgtr]

GDS has a nice set of 36 watt transformers.

[runout1]

I forgot to ask one more thing?!!!
The schematic sais to use 12AX7B
tubes or 12AT7 tubes..? Witch one
should I use? All the ones that I
look at only say 12AX7 on them
there is never a "B" on the end
i dont think? could I just use 12AX7's
with no B?

[jaysg]

I purchased a "cheaper" 36 watt kit.

If it's one of the two I'm thinking of, the PT is probably fine. You should surf the appropriate boards for indications that your PT is unreliable.

Assuming it is reliable, look for a better OT. Mercury Magnetics sets the level of the most you could spend. Backing down from there, almost all of the best North American options are made by Heyboer to the specs of specific vendors. The 36W was invented here, so there's no grail iron to clone. I doubt that you'll end up kicking yourself for buying a better OT. hth

...don't worry about the 'B' thing. That indicates a specific brand, iirc. Not all 12ax7's are equivalent. There have been any number of threads on them, here and at other forums. It's like wine tasting -- tons of opinions. If you don't have extras, you won't be able to swap them around to tell a great one from a good one from a crummy one.

[briane]

speaking from experience, the GDS 18 watt iron rules. I have not used their 36w iron, but I am sure the quality is there.

[Alexo]

I forgot to ask one more thing?!!!
The schematic sais to use 12AX7B
tubes or 12AT7 tubes..? Witch one
should I use? All the ones that I
look at only say 12AX7 on them
there is never a "B" on the end
i dont think? could I just use 12AX7's
with no B?

12AX7B is just the newer Chinese version of the 12AX7, you can use any 12AX7 with any suffix (12AX7A, 12AX7WA, etc.).

[runout1]

I looked around at Mercury Magnetics and
I could not find any 36 watt pt & ot's..
Do I use an 18 watt one for my 36watter
or can I bump up and go with a pt & ot
for a 45 watt pt & ot? Anyone tried to
put in a plexi 45 watt pt and ot in there
18 or 36 watt box? Its probably a dumb
question but I am just curious? Can someone
recommend a Mercury Magnetics 36watt
pt and ot?

[sub]

Vox AC30 PT/OT

[Phil_S]

AFAIK, the 36W is a variant and not a "production" model. For this reason, you may not find transformers specifically for this model at a house like Mercury. For an output transformer, you want on that has a 4K primary (or close to it) and it should be rated for the appropriate wattage. 40-50W rating is good. These won't be cheap.

I don't know this piece of iron, but I suspect something like it would be appropriate. http://www.edcorusa.com/products/transf ... -4_2k.html

Something along these lines from Mercury Magnetics will cost maybe 3x as much.

[runout1]

so If I buy a PT & OT for a
plexi 45 will it work?

[Bulatovic]

I think that with the plexi PT the voltages would be too high - am i right?

[runout1]

I have not idea? than If I
just used the OT would the
amp be louder?

[Graydon]

I have a 36W transformer set. The OT can also be purchased alone if you don't need a new PT. Check out my parts page here...

http://gdsamps.com/?page_id=7

Email me for details. The OT specifically is not posted yet on the parts page but I have them in stock.

My 36W OT is designed to emulate the sound of the GDS/Heyboer 18W OT but with the correct impedance and power for a 36W amp with 4 EL84s. It also has the same footprint so it fits in an 18W chassis.

I've also built a 36W amp using two 18W OTs. It sounded great.

Thanks,