audio-talk

interstage-transformer 833-based 140kg Reference monos outputting 150 watts in class A single-ended triode mode with a 6C45 driving a 300B driving the 833... Trafomatic builds amps of any persuasion particularly since they specialize in custom commissions of late. TruLife does single-ended no-feedb...

I have understood so far that these amplifiers don't need to be particularly powerful. Maybe I got it wrong?

On the other hand, I don't expect this thread, like most other threads, will result in some amps being built... I consider it a "what if" discussion.

You should have told us the info is from the JAC site?! That changes the story from "potentially alarming" to "a joke". While it is a fact that people can find ways to destroy anything, this is about magnetizing the core and thus making the transformer sound bad! Really, if you m...

I don't believe you can destroy a transformer by measuring it with a multimeter! That would be a very fragile unit... what can you destroy, the winding? As for the amps, it all depends on the power needed. There is no particular need to apply DHTs (or DHPs) unless for the sake of doing it (l'art pou...

Steve, I could not resist trying to spoil your fun and enjoyment a little bit ;) Here's my latest creation, the RH300B "official version". Soon on my blog... http://i1262.photobucket.com/albums/ii608/Alex_Kitic/IMG_2848_web_zps7da56f42.jpg I know it's off-topic, but since we are showing cr...

That is definitely some "mechanical" or "construction" issue with your particular tube, and not your amp. A manufacturing defect. It can be seen as obvious on the picture that the tube has lost its vacuum (white getter). Thus it was an implosion that you have heard. Since the imp...

Thank you Paul. That is exactly what I am trying to do: find people who are willing to try and thus be in the position to judge for themselves. Thus when I see that someone who seems a likely candidate, I try to persuade him into doing it. No luck so far. Paul has obviously got a lot of other stuff ...

I must stop spamming all relevant topics with my advice and comments, so this is written instead of some advice or comment.

Mike H wrote:Have stopped watching this topic. Sheesh! Life is too short

Seems like a good idea. In 10 years time it will probably be standard for direct heated tubes. Until then, enjoy what you are used to using for the heaters

The charm of a relatively inexpensive, cool running power supply for very big valves is undeniable. If it is reliable (seems to be) and sonically "inert", we would have a winner! SMPS will do that too. (DC) 1) SMPS is DC, and thus the filamentary cathode is not at the same potential from ...

Not sure why you are taking the 2nd harmonic of your heater frequency, so lets start with a heater 60kHz signal and lets start with a 18kHz audio tone from your music. That will produce a sum and difference of 42kHz and 78k. Thats great you say, neither are audible. However, you seem to be ignoring...

Given Mike has answered, just to correct another misfact. Mike's answer got a rather precise answer (reply) with links for further reading and consideration, thus we cannot assume that what I sad was a "misfact" . As for the other "misfact" : Besides, this distortion seems to be...

I believe Nick G mentioned earlier, one big problem with HF AC is the heterodyning effect, viz 30 kHz (say) mixing with upper treble or ultrasonic in the signal and producing an audible difference frequency. I assume you are referring to Heterodyne? http://en.wikipedia.org/wiki/Heterodyne There is ...

I am not sure how 25Hz AC is going to be inaudible. If nulled, the 2nd harmonic remains at 50Hz which should be pretty audible unless filtered out by the inability of the amp and/or speakers to reproduce it. HF AC on the other hand is definitely inaudible and if the 100Hz hum caused by 50Hz mains re...

This has nothing to do with copy protection! You cannot rip SACD on a computer because there are no drives that can read them, although the SACD layer is a "normal DVD", but a chip is needed to allow reading it: this chip requires a royalty that manufacturers are not willing to pay (high?)...