5E3 Power Transformer

[bk121]

Im putting together a new 5E3 build which I plan on using as my primary home amp. Im using all top components but have a old hammond power transformer sitting around from an old project so considering using that. Its hammonds drop in replacement for the deluxe so it fits the bill . I plan on using a mercury or triode paper bobbin output transformer but wondering if i should upgrade to a "better" power tranny. Does the power tranny really make that much of a difference? should i bite the bullet and upgrade the power tranny or just use the hammond? also whats the general consensus on alinco blues for these amps, i have one of them sitting around but hear alot of people are really happy with old jensens. I dont need the amp to sound exactly like the 5e3, just looking for some good fenderish bluesy tone.

thanks in advance for all who reply.

[black_labb]

the pt does little for tone. more to do with reliability. id give tha alnico blue a try, id imagine it would sound great in there, and worst case scenario is it doesnt, so you would order a different speaker, which you would do anyway if you decided you didnt want the alnico blue.

[Bruce / Mission Amps]

I'd like to know what Hammond PT is a drop in for the 5E3?
And yes, using the wrong PT absolutely will negatively effect the tone of the amp.

[bk121]

well i decided to use the hammond. the replacement is pn# P-TF41316. you can also see:
http://www.tubesandmore.com/scripts/...item=P-TF41316

i do have one question though. it doesnt have a ground for the 6.3v heaters. do i need this in the 5E3? Also next to the center tap I have a blue wire which im not sure what it does. is it the ground? can i just ground the ct and the blue wire together?

[black_labb]

well i decided to use the hammond. the replacement is pn# P-TF41316. you can also see:
http://www.tubesandmore.com/scripts/...item=P-TF41316

i do have one question though. it doesnt have a ground for the 6.3v heaters. do i need this in the 5E3? Also next to the center tap I have a blue wire which im not sure what it does. is it the ground? can i just ground the ct and the blue wire together?

id say you want one end of the 6.3v wonding grounded and the other connected so there is 6.3v. some transformers seem to have 6.3-0-6.3 , they may be for amps that use dc heater current, but im not sure on that.

[bob p]

although its not a "drop-in" replacement, the Hammond 270-FX doesn't suck in a 5e3 circuit.

[hasserl]

well i decided to use the hammond. the replacement is pn# P-TF41316. you can also see:
http://www.tubesandmore.com/scripts/...item=P-TF41316

i do have one question though. it doesnt have a ground for the 6.3v heaters. do i need this in the 5E3? Also next to the center tap I have a blue wire which im not sure what it does. is it the ground? can i just ground the ct and the blue wire together?

The blue wire is to provide a voltage for fixed bias. You won't need it for the 5E3 which is cathode biased, unless you wanted to add fixed bias you could use it.

For the 6.3 volt filaments you would use two 100 ohm resistors to ground as a virtual center tap. You would run the two leads to the jewel light and to all the filaments, then from the last tube you install the two resistors, one from each leg of the circuit, to ground.

[Bruce / Mission Amps]

well i decided to use the hammond. the replacement is pn# P-TF41316. you can also see:
http://www.tubesandmore.com/scripts/...item=P-TF41316

i do have one question though. it doesnt have a ground for the 6.3v heaters. do i need this in the 5E3? Also next to the center tap I have a blue wire which im not sure what it does. is it the ground? can i just ground the ct and the blue wire together?

That link goes to a picture which is not a Hammond PT, it is a custom wound PT made in the USA exclusively for CE Distributors.
Pretty good.
Using it, you'll find that your plate voltage is going to be higher then you expected, maybe much higher... especially if your line voltages are like mine, which is 126vac today!
Also, NEVER ground that blue wire or you're PT could overheat! It is a bias tap, connected right to your high voltage windings and grounding it will short out one side of the secondary, possibly causing some series damage.
Snip it off about an 1 1/2" long and insulate it from touching anything.
Yes you can (actually "must" with a FW rectifier) ground the red/yellow center tap.

[bk121]

thanks for the info guys. i knew it was a bias tap but since im relatively new to amp building ive only used cathode bias and never fixed bias. thinking back on it, it was not a hammod transformer, i was convinced i bought it from a vendor who only carried hammond tranformers but i bought it from the vendor where the link was from. i had purchased a hammond output transformer at the same time so assumed thats what the power was. Just for my own info, would it there be any advantage as to incorporating a fixed bias into this circuit? ive researched the two a bit but its hard to find clear cut info as to why you would incorporate either of the two. Also hasserl, would the heater grounds go to the last tube meaning the 12ay7 or the last 6v6 gt? im assuming the 12ay7 but trying to be sure about things and get things right the first time and get a better understanding of how things work rather than winging it like ive been doing in the past. thank you all again for the info.

[Paul P]

I just went through this question myself and decided to do both based
on the information I got from others in this thread :

http://music-electronics-forum.com/s...ead.php?t=4922

Paul P