Picking Transformers for 5f1-5f2 circuit

[zenit]

I'm currently in the process of building 5f1-5f2. I need to order some transformers. Im thinking about geting AES fender replacements or Hammonds.
I'm thinking about geting Fender replacement 12Watt for output and 325-0-325V 70mA or 330-0-330V 120mA or for output. Did anybody have experience with these transformers in this application? What difference does the power transformer make in terms of sound of the amp?

[Gord K.]

I built an amp based on the 5F1 circuit with the tone control from the 5F2, and I added in a pair of connectors for an effects loop. This circuitry is wired point-to-point in a Hammond aluminum chassis.

My power transformer is a Hammond 272X - 620 V CT @ 70 mA, 5 V CT @ 2 A, and 6.3 V CT @ 2.4 A. I used a Hammond 125E for the output transformer. The speaker I used is an Eminence Legend 1028P and I'm happy with the end result.

Gord.

[Jef]

there's an interesting article on the Angela Instruments website, discussing building a single ended 6V6 amp, based on the tweed champ and princeton. There's some useful info on transformer choices.

go here:
http://www.angela.com/catalog/how-to/Single.6V6.html

have fun!
Jef

[JDO]

if i remember correct the 5f1 has 340vdc on the first node. and i think the 5y3 drops something like 50-60v. so let's say 400vdc.
400vdc/1.4=285vac
hammond makes a 275-0-275 which will actually be
(120/115)*275=287 (assuming you're in the US and you have higher wall voltages like everyone else). that one should be fine if you're going with a tube recto.

BUT in a single ended amp there is no advantage to having a tube recto (assuming you'll have a standby switch). there won't be any sag in a SE amp - and IMO there is no reason to use a tube recto unless you're looking for sag.

so you could look at getting the hammond that's 240v but it's only rated at 50ma. but i've heard hammonds are tough and can easliy handle being driven harder.

but, you might want to look at weber's. they are starting to carry trannys. his champ pt is going to be 35 bucks. and the OT is going to be 20. all in all, that's pretty good pricing.

now on to the question - what affect do the PT's have on sound? that's tricky. the answer is none and some. when you change the voltage in an amp you change the tone and feel. you can never get a bf champ to sound like a tweed because of the higher voltages. but, as long as the voltages are close (+/- 10-20%) you should be fine.

hth some.

[zenit]

Lets say i get a Hammond that does 350-0-350 @ 110...Would it still be usable in this circuit? Also if i go with larger PT, would I be able to use different tubes like 6L6?

Originally Posted by JDO

if i remember correct the 5f1 has 340vdc on the first node. and i think the 5y3 drops something like 50-60v. so let's say 400vdc.
400vdc/1.4=285vac
hammond makes a 275-0-275 which will actually be
(120/115)*275=287 (assuming you're in the US and you have higher wall voltages like everyone else). that one should be fine if you're going with a tube recto.

BUT in a single ended amp there is no advantage to having a tube recto (assuming you'll have a standby switch). there won't be any sag in a SE amp - and IMO there is no reason to use a tube recto unless you're looking for sag.

so you could look at getting the hammond that's 240v but it's only rated at 50ma. but i've heard hammonds are tough and can easliy handle being driven harder.

but, you might want to look at weber's. they are starting to carry trannys. his champ pt is going to be 35 bucks. and the OT is going to be 20. all in all, that's pretty good pricing.

now on to the question - what affect do the PT's have on sound? that's tricky. the answer is none and some. when you change the voltage in an amp you change the tone and feel. you can never get a bf champ to sound like a tweed because of the higher voltages. but, as long as the voltages are close (+/- 10-20%) you should be fine.

hth some.