5y3 to 5u4 swap?

[lexluther]

5y3 to 5u4 Any advantage? Just wondering if the amp would sound cleaner at higher volumes less sag?
Thanks again this group is great.
Luther

[Damon]

Depends on the amp! What amp?

The 5U4 wants a whole amp more filament current (3A as opposed to 2A for the 5Y3), so I'd watch your PT for overheating if you're gonna try it. Chances are yes, the 5U4 is going to kick out a few more volts than a 5Y3, and will sag less.

[Geetarpicker]

I 5V4 might give you a more than the 5Y3 and I don't think it draws more filament current unlike the 5U4. However the B+ might be too high, but it might be worth checking into.

I recently experimented with my '64 non-reverb Deluxe. The stock Mullard GZ34 was putting out about 460v, a 5V4 about 10v less, and the 5U4 about 10v less than that. Our wall power around here is about 125-126 so I was actually trying to tone it down a bit not boost it.

[Blue Strat]

There's no generic answer to this question. It depends on the amp, the voltage ratings on the power tubes, the capacitors, and what the plate voltage is now.

This article answers all the issues. http://www.kcanostubes.com/content/newsletter_details.asp?ArticleID=3

[lexluther]

The amp is a dearmond r15t with rather beefy transformers. 5e3 type amp. I was just wondering . Thanks

[Blue Strat]

The amp is a dearmond r15t with rather beefy transformers. 5e3 type amp. I was just wondering . Thanks

You would have to take measurements and check component specs as mentioned in the article.

5V4s are usually a safe bet. Increasing the value of the cathode resistor to about 350 ohms combined with a 5V4 recto usually gives the biggest, safe, headroom improvement in 5E3s.