The Hundred-Buck Amp Challenge

I v-carved it on my DIY CNC router and filled the letters. Here's an example... W9WadZ2.jpg

Same with the back....

View attachment 922915
 
Looking for a cheap power transformer to do a P-P (something like 6V6 or EL84) design.

It seems that there is an error in this spec for the Weber WRVBPT, anyone know for
sure? It has 260V at 100mA for use with a voltage doubler and 6.3V at 3A. They
call it a 10W transformer but the 260V winding is 26W and the 6.3 about 19W for a
total of 45W:
WRVBPT Transformer – Weber Speakers

It is only $28.25

It seems like they rate their power transformers as for use in a XYZ power output amp,
but I'm not sure about this one.
 
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Similar cost to Antek toroids, pretty good price if you don't need a 5 volt winding and intend to do solid state for rectification-

Tube Amp Parts - Power Transformers - Page 1 - AnTek Products Corp

240 volt secondary

280 volt secondary

If you want to get creative these work well for outputs too, I use a pair of these with the secondaries in series to do 20-25 watts out of a pair of EL86 at a reflected ~4k or so load.

5 volt dual secondary 50VA

Lots of iterative math and creative miswiring can be done to get different impedances. With the bigger transformers you could build a nice cheap amplifier for some of the bigger sweep tubes.
 
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PRR

Member
Joined 2003
Paid Member
.... They call it a 10W transformer but the 260V winding is 26W and the 6.3 about 19W for a total of 45W: WRVBPT Transformer – Weber Speakers.....

Yes, it is "for a 10 Watt amplifier", not "a 10 Watt transformer".

Take simple amp plate efficiency as 40%. 40% of 26W is 10.4W. The 0.4W could be for preamp and drivers. We actually should account for difference between VA and Watts, too. But life is short.
 

Thanks PRR that makes sense, so the ratings are correct.

AES charges $12 shipping here it is at reverb.com also for $25 but with free shipping,
anyone know if reverb.com is legit?
Transformer - Output, Replacement for Blues Junior, 15 W | | Reverb

Odd, it says shipped by Amplified Parts at reverb.com and if you go to Amplified Parts
and try to buy it there the shipping is also $12. Reverb somehow provides free shipping?
Transformer - Output, Replacement for Blues Junior, 15 W | Amplified Parts

It seems that Reverb.com was bought by Etsy, both have low ratings at the
Better Business Bureau but this is a simple transaction. I bought one and
paid by PayPal it was the base price of $25.15 + $1.60 sales tax for $26.75 total.
Will report back.
 
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Should have looked first at the BBB about Reverb.com, rating is 1.06/5 with lots
of complaints. This is a new transformer from what looks like a reasonable amp
company so I'm hoping for the best:
https://www.bbb.org/us/il/chicago/p.../reverbcom-llc-0654-88654144/customer-reviews
What this mainly tells me is Reverb, like most businesses, isn't a member of the BBB. The BBB's main business is protecting it's member companies from bad publicity as best it can.

The free shipping thing is a mystery to me, unless they're shipping from China, which seems to have a lot of government subsidies for international mail.
 
What this mainly tells me is Reverb, like most businesses, isn't a member of the BBB. The BBB's main business is protecting it's member companies from bad publicity as best it can.

The free shipping thing is a mystery to me, unless they're shipping from China, which seems to have a lot of government subsidies for international mail.

I was mistaken, the low rating was from individual people, but BBB gives
them an A+ and they are a BBB member which is as you suggested.

I got a high rating from them for paying fast, and a UPS tracking number
indicating it should be here in a few days.
 
I'm looking for a cheap replacement for a 6L6GC and remembered this
old list of compactrons from years ago:
Compactron Tubes: A Junkbox Guide

The 6LU8 looks like a good replacement for a 6V6 and includes 1/2 of a 12AT7
for the driver, but is the beam power section NOT a sweep tube? People claim
that it is like a 6V6 but the 6LU8 transconductance is much higher.

I'd have to go through the higher power tubes to determine if there is one that
is even close to a 6L6, is there one known to work well?