New amp project in the works

[the guy who invented fire]

Re: New amp project in the works

I don't know first-hand about the (modern-day) hand-wired ones, but the PCB reissues with the Sovtek 5881s sound like ass (which is why I modded mine extensively).

In fact, I don't know what Marshall was smokin' a number of times with their "reissues"; the component values being so far off from vintage spec.

Most likely they just did it for the $$$. As I understand, the hand-wired ones are much better.

Was gonna say, not sure if you're going KT-66, but if you're not (and going with 8-pin pentodes a la EL34s), you might wanna give the (new stock) Electro-Harmonix 6CA7s a try. Big, clear tone that crunches beautifully when cranked.

Thanks!

I have a pair of old Phillips 6CA7's in my tube stash but I think this build is either get 5881's or KT66's...more than likely KT66's but since i have a stash of old glass 5881's I'm sure I'll give a set a try at least once!

 

[the guy who invented fire]

Re: New amp project in the works

Very cool! I wouldn't know the first thing about building an amp, but I admire those that can!

Make no mistake...I am not embarking on this alone! My father is truly gifted when it comes to tube circuits. In fact he has built all the amps he owns...I don't think he's actually bought an amp in nearly 20 years now and I have enlisted his help!

 

[Gone_Shootin]

Re: New amp project in the works

Awesome, I'll be watching this one.

 

[PFDarkside]

Re: New amp project in the works

So... Any updates?

 

[the guy who invented fire]

Re: New amp project in the works

So... Any updates?

No, not really.

I let it take aback seat while my dad and I built a Telecaster for him then there was Thanksgiving, Christmas, New Years, etc..,

I did, however nail down the last of the NOS parts I needed...a few more Lemco silver micas, another Philips mustard cap and a handful of Allen Bradley carbon comps.

I hope to have a fully running chassis in the next few months but it just depends.

I'm still in the hunt stage to for some stuff.

It'll be a while longer before its done but I'm working slow and steady to make sure I get it right!



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[Demanic]

Re: New amp project in the works

6CA7's are quite under rated.

 

[the guy who invented fire]

New amp project in the works

6CA7's are quite under rated.

And will be no where near this amp!

KT66s or 5881s are really the only choices for a correct JTM-45 in my opinion.

I'll likely go with the KT66s but I suspect I'll try 5881s at least once.


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[Demanic]

Re: New amp project in the works

You're the one making it.

 

[GilmourD]

Re: New amp project in the works

6CA7's are quite under rated.

I completely agree.

And will be no where near this amp!

KT66s or 5881s are really the only choices for a correct JTM-45 in my opinion.

I'll likely go with the KT66s but I suspect I'll try 5881s at least once.


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However, yes, KT66 OR 5881 is what you need for that sound.

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[MetalManiac]

Re: New amp project in the works

I don't know about Marstran, but a E.E. told me that Heyboar are the best- betert than MercuryMagnetic.
Anyway, I applaud the OP. I am doing somthing of the smae, but with a different approach.
I am going to modify my Traynor Bassman /Plexi.
I am going to first fix the circuit to 100% vintage Bassman or Plexi.
Then from there decide to make it a Plexi.
After that, I can do the Rocstah/LMARA/PPIV. Thia would be to bring the old amp quite close to teh old Plexi VH1 Brown Sound HOT ROD PLEXI amp.
(Disclaimer-not a tech..just doing -preliminary footwork)

 

[xxxplorer]

Re: New amp project in the works

When it comes to the companies like Marstran, Heyboer, Mercury... It's just a choice. All are great, just depends what you're going for... I just don't like paying for Mercury's add campaign lol.


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[PFDarkside]

Re: New amp project in the works

Anyone have a good link or resource that talks about Output Transformers as they relate to tone?

(From my perspective, it's an impedance matching device, transforming high voltage low amperage to low voltage high amperage. As long as the component can withstand the wattage and matches impedances correctly that's all that "matters". Which is correct from an engineering standpoint but we all know the small technical details are where the tone implications live.)

 

[MrTondo]

Re: New amp project in the works

Anyone have a good link or resource that talks about Output Transformers as they relate to tone?

(From my perspective, it's an impedance matching device, transforming high voltage low amperage to low voltage high amperage. As long as the component can withstand the wattage and matches impedances correctly that's all that "matters". Which is correct from an engineering standpoint but we all know the small technical details are where the tone implications live.)

Google gives this:
click here