Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: animalchin on December 21, 2021, 01:26:36 pm

Title: 1482’ing a 5E3
Post by: animalchin on December 21, 2021, 01:26:36 pm: Hello!
This is my first attempt in the world of amp building and I thought I would try and do something a little more fun than a 5E3 while keeping the complexity pretty much the same.

Here is my work in progress diagram of a Silver Tone 1482 (with the tremolo circuit removed) mapped onto the layout of a Fender 5E3. (https://i.imgur.com/M3AgWfU.jpg)

Here are the schematics for each amp
(https://i.imgur.com/mzAsz2q.jpg)

(https://robrobinette.com/images/Guitar/5E3P_Build/5E3_Schematic_Annotated.gif)

I have a few questions.

I know that I need to draw in the correct power transformer and rectifier setup.

However, is the 6X4 worth the added hassle versus just using the stock 5Y3 setup from the 5E3?

I have never even played an amp with a tube rectifier, so I am totally unexperienced with the oft-mentioned “saggy/squishyness” in comparison to silicon diode rectification, but I am curious as to the different sonic/feel characteristics between the 6X4 and the 5Y3 and how much they each contribute to their respective amps sound.

I think the issue for me would be sourcing a 240V power transformer for the 6X4 here in the UK but I’ll get to that in due course.

I have always wondered how to determine what power and output transformers to use (especially if a schematic has no listed voltages) so I am in the dark when it comes to this.

I’ve realized that the jumper replacing the power tube grid stopper resistors in the layout is unnecessary and that I should just connect the grid leak resistors to pin 5 of the power tubes.

I don’t want to get ahead of myself, but I would also like to hear your thoughts on any “must-have” or interesting modifications or tweaks to this kind of amp. I only play at home so I might add a master volume control.

How am I getting on so far with my layout? Any glaring mistakes?
Thanks!
Title: Re: 1482’ing a 5E3
Post by: sluckey on December 21, 2021, 01:47:16 pm: You may be interested in this...

http://sluckeyamps.com/misc/Silvertone_1482.pdf
Title: Re: 1482’ing a 5E3
Post by: tubenit on December 21, 2021, 04:17:52 pm: Quote
However, is the 6X4 worth the added hassle versus just using the stock 5Y3 setup from the 5E3?

I had a Dan Electro Centurian and it's pretty much the same as a 1482. It's the only amp I got rid of that I really miss.

I would just use the 5Y3, but note the Sovtek and some modern 5Y3's give higher voltages than the vintage ones.

I would rely on Sluckey's most excellent documentation and work.

with respect, Tubenit
Title: Re: 1482’ing a 5E3
Post by: Platefire on December 21, 2021, 10:25:08 pm: Hello
I'm an old 1482 fan. Just a thought to consider. A 1482 is a pretty dark amp normally. You might consider using the 5E3 tone control on one of the channels as kind of a bright channel. A Fender Strat or Tele sound fairly bright though a 1482 but a Les Paul/335 can get pretty mushy. The bright channel would be good for that. Platefire
Title: Re: 1482’ing a 5E3
Post by: isaac_teller on December 23, 2021, 01:26:52 pm: Hello. I noticed that there is no bias resistor on the cathodyne phase splitter in both the Centurion and the 1482. Is this a mistake on the schematics? Would it improve things to add a bias resistor(what value)?
Title: Re: 1482’ing a 5E3
Post by: shooter on December 23, 2021, 02:37:22 pm: Quote
what value
the Fender schematic shows 1.5k, probably a good place to start.
Title: Re: 1482’ing a 5E3
Post by: PRR on December 23, 2021, 08:30:37 pm: Quote from: isaac_teller on December 23, 2021, 01:26:52 pm
Hello. I noticed that there is no bias resistor on the cathodyne phase splitter in both the Centurion and the 1482. Is this a mistake on the schematics?...

It is "wrong". It works fine, in most cases. Any loud peak will charge-up the grid cap enough to keep it out of grid current and gross distortion. It saves a part, and a tie-point.