Securing a window maker amp with iso tranformer

[VinZenT]

Hi dear amp & guitar lovers,

I recently bought an old amp from the 60's.

Great tone but also great danger : the tube heaters are directly connected to the power cord (117V, big current).
After some research, I decided to install an isolation transformer to feed the tube heaters.
I'm not an expert but I have enough skills to install the iso trans in full safety and also add a fuse and a 3 prong cable.

But I'm puzzled about what to do with the "death cap" : should I remove it ?

Here is a picture from the amp internals : the "death cap" is, I think, the yellow cap connected from the switch to the ground, on the right.

Just for information, I plan to buy the Triad Magnetics N-68X iso trans.

I have a "global" picture of what to do, but I prefer to ask the community for the "détails" since this "global" view could kill me ....


Many thanks for your advice.

Vincent

 

[Musekatcher]

Death Cap is Deadly and Spreading

image removed

But seriously, this is a good thing to use anytime, not just with old amps. Had a recent incident due to faulty venue wiring:

https://www.amazon.com/Toolocity-AS...&qid=1497519515&sr=1-23&keywords=ground+fault

 

[VinZenT]

Good advice, and good device.
I take it !
Thanks

 

[24 track]

I recently found this at a Value Village for 12.00 A Pine /Pepco widow maker , Pepco was kind enough to leave this schematic on their site

I havent done the mod yet but after I retubed the amp it sounded great!

Pepco did not give the model # of the transformer to use but this will be a project for another day ( I wont use this on a concrete floor or while Im standing in water.)
but it does use a solid state bridge rectifier.

Im not a fan of death caps and I have only removed one from a an early '70 fender super but I found a a how to on Youtube by some one who was very thourough in the process and i followed that

 

[robrob]

If the death cap is connected from hot or neutral to chassis then yes, delete it. The three prong cord will give you the noise shielding the death cap was designed to provide.

 

[VinZenT]

If the death cap is connected from hot or neutral to chassis then yes, delete it. The three prong cord will give you the noise shielding the death cap was designed to provide.

Thanks for your answer RobRobinette.

I think this is indeed my situation here, right ? :

 

[VinZenT]

I havent done the mod yet but after I retubed the amp it sounded great!

Pepco did not give the model # of the transformer to use but this will be a project for another day ( I wont use this on a concrete floor or while Im standing in water.)
but it does use a solid state bridge rectifier.

Im not a fan of death caps and I have only removed one from a an early '70 fender super but I found a a how to on Youtube by some one who was very thourough in the process and i followed that

Nice amp !
I love the cover / tolex / whatever on the cabinet.

 

[zook]

Securing a window maker amp with iso tranformer

The amp makes windows?

 

[robrob]

Yep, that's is a death cap. Remove it.

 

[slacquin]

design by bill gates of hell I suppose

 

[Staypuft1652]

Blue screen of death.

 

[TwangToInfinity]

wow those amps have such a pure signal path!

i'm lazy i would use a wireless

 

[flyingbanana]

Some of those Pepco Paul amps look very similar to my 60's Univox U45 amp, right down to the tolex.

 

[VinZenT]

Thanks all, for your suggestions.
And, yes, Zook, this is more a Widow maker than a Window maker.

Having said that, I just discovered that installing a iso transformer in a transfo less amp is easy.
But installing a iso transformer in an amp already having a power transformer is something I've never done before.

May I ask, please, for some suggestions ?
Here is the schematics I've done (not completely done on the guitar input and preamp, but all the power circuit is here).

I have trouble to see where to install the iso trans :
- Before the existing power trans (the iso trans feeding the power trans) ?
- After the power trans (power trans feeding the iso trans) and, in that case, should I change the heaters wiring ?

Well,

Once again, thanks for your help.
I know I should shut up and bring this amp to a qualified tech but, on the other hand, I want to learn ....

Vince

 

[VinZenT]

I have trouble to see where to install the iso trans :
- Before the existing power trans (the iso trans feeding the power trans) ?
Vince

I'm asking that because the iso trans (N68-X) can use 230V on primary. That way, I could use it without any step down transformer (230V here in Switzerland).

 

[robrob]

Yes, normally the iso transformer feeds the power transformer. You would disconnect the power cord from the fuse and power transformer, then hook them up to the iso transformer. The power transformer's primary wires would then be hooked directly to the iso's output.

 

[VinZenT]

Yes, normally the iso transformer feeds the power transformer. You would disconnect the power cord from the fuse and power transformer, then hook them up to the iso transformer. The power transformer's primary wires would then be hooked directly to the iso's output.

Great ! Thanks a lot !
I thought I was wrong trying to connect the iso that way.
That will be a lot easier now.
I'll come back and post pictures of my work as well as more picture of this little but awesome Lectrolab amp.
Vince