I'm currently having a little play around with this Transcription Audio amplifier. Its massive !!
Printable View
I'm currently having a little play around with this Transcription Audio amplifier. Its massive !!
Talk amongst yourself :scratch:
Blimey, that’s an odd looking thing - I can’t tell on my phone but is that copper, wood or Bakelite?
How does it sound ?
Sorry, didn’t mean to come over critical - does look like a heck of a thing - as you say, massive! :).
The casing is heartwood, which is very dense, hard to work and is the centre of the tree which is notionally 'dead' and rich in resins etc and darker in colour. It is possibly the nearest natural wood to man made panzer wood which is the holy grail for vibration damping. Trim is copper sheeting. -- and yes it is draw droppingly ugly and massive.
It is a SET and the two triodes are VT-4-Cs which are transmitter tubes from the 1940's (NOS). They are fore runners of the 211 triodes. They have thoriated tungsten filaments so glow brightly like a light bulb. I will try and get some night time pictures.
Will try and do a review later but at the moment it is the best amplifier I have ever had in my system (over 50 years). Inside it has half wave valve rectification, massive mains transformer, an oil filled 2Kv capacitor the size of a Tupperware lunchbox, interstage transformer and C core output transformers. Output is about 23 watts I believe. Driver valves are E182cc and the valve rectifiers are CV187
I like it, big triode sound, I expect it kicks out some heat.
How much are the power valves to replace?
The VT-4-Cs do kick out some heat - about the same as two 100w tungsten light bulbs. The valves are no more expensive than 300Bs. Some, like my GE 1940's valves are becoming collectors items because or their SQ and can fetch up to £1000 a pair, but the Western Electric 300Bs can sell for more than this.
It does make the 45 triodes look exceedingly good value at about £100 for a NOS pair. I believe massive stocks of these transmitter valves were set aside by the American War Dept during WW2 and are gradually being released onto the open market.
The rest of the amp, inc transformers, runs quite cool as it is massively over specified. This also has the benefit that the transformers are not working over hard and are therefore mechanically silent.
Did a 211 shootout between KR 211, Amperex, RCA and GE with 4 people.
SQ pecking order ranked Amperex the best. GE are OK, though.
That's not using my own amps, which require 4 211s, where I also rank Amperex the best (but never had the KRs in those).
Scoring Amperex 211s is hard these days.
Actually 211s used to be cheap as chips due to US army stocks. They still were in the 70s and 80s. Not true anymore, supplies are drying up I believe but GEs are the most abundant NOS 211s.
What you really want is a couple of STC 4242 metal plates according to PQ from Audionote who ranked it the best a while ago after trying a lot of options.
However it is a safe bet to say that, since getting a pair is extremely hard. Or a quad in my case. I would pay quite a lot of money for a quad, I must admit.
I have found NOS 211s to be extremely reliable. You'll probably never manage to wear a pair out if they were unused to start with.