dberning

Responses from dberning

I have just purchased the latest Sound Lab M1
Some would conclude that my description above in many ways describes the characteristics of an audio output transformer, except for the dc-coupling attributes. In fact, the ZOTL can accurately be described as an ideal output transformer emulation ... 
I have just purchased the latest Sound Lab M1
Hi Ralph,It looks like itÂ’s time for me to get involved in doing the best I can to explain the ZOTL technology so more people can understand the real issues. It is good that you pasted my patent abstract into your post, and from the complexity of ... 
more reliable amp: tube or solid state class A
Hi Ralph-You are technically correct according to most published definitions of class A, which usually define class A as being an amplifier in which output devices conduct for the entire cycle. However, I should point out that the definition of cl... 
more reliable amp: tube or solid state class A
Amp reliability is determined by the level of conservative design, and this applies to tube and SS. The reason that SS class A amps tend to be more reliable than tube class A amps is that a SS amp will blow up immediately if it is not designed wit... 
Need help understanding tube wpc
Watts are watts, whether ss or tube. How loud an amp can play without objectionable distortion (to the ear) is related to how gracefully it overloads. Tube amps are better in this in that they use less negative feedback. If the same excessive feed... 
Are MOSFET's voltage, not current, devices?
Actually, MOSFETs have a very high output impedance, typically in the megohms for a modern power device. Bipolars do too, although slightly less as reduced by the Early Effect. The output impedance of pentodes is lower, typically in the tens of k-... 
tube amplifier auto bias- accurate?
As one who has built both auto-bias and fixed (pot-adjustable)bias amps (EA230 etc.)over the years, I can tell you that the only advantage to fixed bias is low cost. This assumes that the auto bias is implemented properly. For auto bias, I have us... 
Otl's with AvantGarde Duos?
Ralph-The transformers, of which there is a pair for push-pull in the ZH270, are power-conversion transformers that operate at fixed frequency. They have low-loss ferrite cores (not air core) optimized for 250 kHz. They are indeed critical compone... 
Otl's with AvantGarde Duos?
The comment that Ralph made in regards to me having admitted that the ZOTL is not an Output-Transformerless amplifier in PF magazine is incorrect. What I stated is something to the effect that the ZH270 is full of transformers, but none are output...