In Reply to: RE: Why are OTL amps not so popular posted by richardl on July 23, 2012 at 11:00:17:
I agree that OTLs run hot, and are rather inefficient. But I don't think think it is really true to say they are particularly low in power (i.e. audio power) in comparison to tube amplifiers with transformers. Nor is it reallly the case that they have high output impedance compared to tube amplifiers with transformers; quite the opposite, in fact.
For example, the Tim Mellow OTL amp, with just two 6C33C output tubes, is 25 watts rms and an output impedance of about 0.25 ohms. The Alan Kimmel circlotron, with eight EL509 output tubes, is about 210 watts rms, with an output impedance of about 0.5 ohms. Even the "lite" version, with only four output tubes, claims to be about 100 watts rms output, with an impedance of 0.8 ohms.
They can be pretty simple to build too, as for example the Tim Mellow design.
Chris
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Follow Ups
- RE: Why are OTL amps not so popular - cpotl 10:40:29 07/24/12 (5)
- RE: Why are OTL amps not so popular - richardl 11:46:12 07/24/12 (4)
- 8 ohms is easy for a 6AS7-based OTL with only 8 power tubes- - Ralph 13:45:48 07/24/12 (3)
- I agree - richardl 10:57:28 07/25/12 (2)
- RE: I agree - Ralph 13:52:49 07/25/12 (1)
- Thanks, I did not know that. - richardl 13:29:31 07/26/12 (0)