Can I use this PT for something?

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Meat&Beer
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Can I use this PT for something?

Post by Meat&Beer »

Hey guys,

My Dad always snatches up electronic goodies for me that the vocational school he works for is throwing away. This is the PT in an Orion tube voltmeter.

Can I make an amplifier out of this? 840v seems like an awful lot, but man I could run a big pile of tubes with it!

What are your thoughts? Too much?
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Reeltarded
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Re: Can I use this PT for something?

Post by Reeltarded »

Only below 10,000ft.

Umm a 90w KT88 Marshall thing that is hard to control.
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Meat&Beer
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Re: Can I use this PT for something?

Post by Meat&Beer »

Wuddya mean hard to control? Fizzy?

I do have a tendency to lean towards amps with far more gain than necessary. A Marshall type would be neat...

I also think I noticed if anything can come from this, it'd be a SS rec, or some messing around to be done with the 7.3?
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Reeltarded
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Re: Can I use this PT for something?

Post by Reeltarded »

Oh no I missed the 75mA cap on that massive mouse.

I am not savvy enough ta know what to do with that one.
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matt h
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Re: Can I use this PT for something?

Post by matt h »

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Meat&Beer
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Re: Can I use this PT for something?

Post by Meat&Beer »

I've heard some of the Ghetto UL amps around here, some amazing sounding little buggers! I don't have a spare any kind of OT kicking around that I can use, just kicking the idea for this PT around for now..

If someone ends up really getting me going on something here, I have no problems buying the right one. I am liking the sound of a shredders GUL SE KT88 though! :twisted:

The GULSEKT-88. Hmmm.

I am pretty inexperienced with this stuff, that's why this is such a good place for a fellow such as myself. Looking at the FW rect with choke looks very familiar to me, essentially the same as is in the build I'm currently working on. I believe we're assuming a SS rect, right?

Thanks so much for your input, I mean it! Below is what I'm seeing for schems on the rectification.
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Leo_Gnardo
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Re: Can I use this PT for something?

Post by Leo_Gnardo »

Before mounting on a chassis I'd suggest using it to slightly flatten that delicious looking burger you have on your avatar, so you could get a bite on it. :P Aside from that I t'ink matt h has the best idea so far. The hi voltage secondary is a bit unwieldy for much of anything else, and you're a little shy of filament current to run more than one big power tube successfully. OK maybe a pair of 6L6 but that's so - ordinary. Maybe a KT120 instead of KT88.
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matt h
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Re: Can I use this PT for something?

Post by matt h »

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Meat&Beer
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Re: Can I use this PT for something?

Post by Meat&Beer »

Thanks for the replies, gentlemen!

The more looking and listening around I do about this subject, a SE KT-88 seems like the ticket. With a big fat preamp that has too many stages.

Any suggestions on what builds/schems I should be looking at? The variant David Root made from the "HoSo56" might seem like a good jumping off point. That, is one delicious sounding amplifier. It's here:

https://tubeamparchive.com/viewtopic.ph ... sc&start=0

Goin' for gain, if I haven't been clear on that one. :wink:

I'd like to also add, I feel awful taking peoples hard work they've done, and cashing in on not only that, but on their overwhelming knowledge that was also hard earned to be able to conceive it in the first place. I hope that if I "borrow" from anyone that I'm not looked down upon, rather, it would be more-so viewed as a compliment/part of the learning by doing process?

I love you guys. :)
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Meat&Beer
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Re: Can I use this PT for something?

Post by Meat&Beer »

Something I probably should have inquired about in the first message...

Just because I have this hunk of iron, does it mean I should find a use for it? I don't buy into ALL of the mojo/black magic voodoo of some aspects of amps, but I DO know that a quality amp is made from quality iron.

But this is the PT, does tone really come from power supply? I'm thinking not so much. Alas, would any of the veteran builders out there skip over this as a potential candidate for a great sounding amp?

Don't wanna get too ahead of myself here.
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Re: Can I use this PT for something?

Post by JazzGuitarGimp »

Meat&Beer wrote:Something I probably should have inquired about in the first message...

Just because I have this hunk of iron, does it mean I should find a use for it? I don't buy into ALL of the mojo/black magic voodoo of some aspects of amps, but I DO know that a quality amp is made from quality iron.

But this is the PT, does tone really come from power supply? I'm thinking not so much. Alas, would any of the veteran builders out there skip over this as a potential candidate for a great sounding amp?

Don't wanna get too ahead of myself here.
Let's say you've decided to build the SE KT88 amp, regardless of whether you use this PT, or buy a PT. Whether this PT has "mojo" or not doesn't really enter into the equation, right? Use this PT, save some duckets. Seems like a match made in heaven!
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ToneMerc
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Re: Can I use this PT for something?

Post by ToneMerc »

420 volts @ 75mA will work if you want to build a SE amp based around one 6V6. That PT was designed for a piece of test equipment, not for the plate current of an audio amp.

FWIW, a quality amp is has litlle to do with quality iron if a persons skills level or craftmanship is in the dirt. A quality amp is the sum of every aspect of the built.


TM
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Colossal
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Re: Can I use this PT for something?

Post by Colossal »

ToneMerc wrote:420 volts @ 75mA will work if you want to build a SE amp based around one 6V6. That PT was designed for a piece of test equipment, not for the plate current of an audio amp.
+1

A KT88 SE is going to clock in around 100mA at 360-370V on the plates.
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Re: Can I use this PT for something?

Post by Leo_Gnardo »

Meat&Beer wrote:Just because I have this hunk of iron, does it mean I should find a use for it? I don't buy into ALL of the mojo/black magic voodoo of some aspects of amps, but I DO know that a quality amp is made from quality iron.

But this is the PT, does tone really come from power supply? I'm thinking not so much. Alas, would any of the veteran builders out there skip over this as a potential candidate for a great sounding amp?
My answers for both.. 1) Some might look at this as an analogue of an imaginary "Leave it to Beaver" plot: kid finds an old steering wheel in the woods "Hey guys isn't this cool! Let's build a car around it..." but it's a lot easier to build an amp than a car, so regardless, I think it's OK. and

B) One can look at an amp as being a modulated power supply. So the quality of the supply DOES matter, as does everything else. And doubly so for a single-ended amp, because you don't have the near-magical feature of hum-canceling in a push-pull output transformer. To avoid hum and unwanted signal modulation it's important to have a very well filtered power supply. So it's - lack of tones you don't want - that comes from a well made supply. Here's to your monster Champ, we'll keep watching this space.
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ToneMerc
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Re: Can I use this PT for something?

Post by ToneMerc »

Assumming all the HT current is dedicated to the power tube plate and also assumming it's wound at the common 75% duty rating, it will support 20.4 watts @ 370V.

Keep in mind SE Fender Champ specs are around 60-70mA.

TM
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