Sufficient to drive an Express?

Express, Liverpool, Rocket, Dirty Little Monster, etc.

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Oddvar R
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Sufficient to drive an Express?

Post by Oddvar R »

Any views on whether this PT can drive an Express?
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Colossal
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Re: Sufficient to drive an Express?

Post by Colossal »

Ideally, you'd want a 300-0-300VAC secondary to build a proper Express running 6V6s or EL34s. The taps on your PT are 330VAC and 360VAC; a bit too hot for an Express. You could be sneaky and use the 100VAC primary (on 120VAC) and lower the secondaries, but honestly I would not recommend doing that or any other tricks to get by. For me, I try to get the right PT for the task at hand. If budget or convenience is your primary concern, then you could run a zener diode or string of diodes on the centertap to lower the voltage. The Express is designed specifically to run at 395VDC on the plates into a 6k6 primary impedance. That's the Trainwreck formula. Deviate at your own peril! :wink:
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didit
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Re: Sufficient to drive an Express?

Post by didit »

Also note 200mA really is too lean. One should have ~300mA primary HT feed.

Best .. Ian
Roe
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Re: Sufficient to drive an Express?

Post by Roe »

it will work but may not be ideal. try the 125v primary and the 660v secondary. voltages at idle will be too high, except for the the heaters. but it will sag more than an express
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Oddvar R
Posts: 487
Joined: Tue Jan 09, 2018 7:39 am

Re: Sufficient to drive an Express?

Post by Oddvar R »

Thanks for that, I'll probably get another transformer then, what transformer is the better to use, and still is available? Is this worth the price you think? I see Classic Tone makes one too?

https://www.don-audio.com/Edcor-XPWR066 ... ransformer
Groove1
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Joined: Sat Dec 05, 2009 12:37 pm
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Re: Sufficient to drive an Express?

Post by Groove1 »

Oddvar R

you are looking for a PT in an EU Online Shop?

Maybe you have a try there: https://www.tube-town.net/ttstore/Trans ... anguage=en

Best, Groove1
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