KT150

[Greg]

Rhetoric ?

Hmmm........harsh!

[Cressy Snr]

Come on chaps, let's not start all that nonsense that took place on DIYAudio ferchrissakes!

The RH84 introduced me to the delights of single ended pentode amps.
OK I now build push-pull amps but that little EL84 amp sounded fantastic and
made EL84s one of my fave valves, second only to the KT120.

the point is Alex you are not going to get an argument on here, so there's no point looking for one. This forum is different to all others.

[pre65]

the point is Alex you are not going to get an argument on here, so there's no point looking for one. This forum is different to all others.

My point exactly.

[IslandPink]

Ah, the mystery is solved !
I did go through some of your recent threads ( Steve ) trying to check for any reference to Alex's site or 'RH amps' , because I thought it looked too much like a spam post , coming out of the blue like that . I apologise.

I just haven't been following the PP threads that closely, that was where you started, was it ?

[Cressy Snr]

Aye..Alex was instrumental in my introduction to SEPs, Schade type feedback schemes and pentode output stages.

I've gone a bit further since of course, but the thing is, Alex does seem to get himself into a lot of arguments on forums.

I was just saying that if he is on here looking for a big fight, he's unlikely to get one. We've had our moments, but generally we don't do bad feeling on here. That's what makes this place different.

[Greg]

I was just saying that if he is on here looking for a big fight, he's unlikely to get one. We've had our moments, but generally we don't do bad feeling on here. That's what makes this place different.

OK, I'm ignorant of the history and without doubt, I sign up to this place being no bad feeling and consequently nicely different.

[Alex Kitic]

Aye..Alex was instrumental in my introduction to SEPs, Schade type feedback schemes and pentode output stages.

Thank you Steve for mentioning that detail. I am always glad to hear how my designs ("work") have had positive influence on people, and while I am not intent on teaching, it seems that sometimes that is just what I accomplish to do.

I was just saying that if he is on here looking for a big fight, he's unlikely to get one. We've had our moments, but generally we don't do bad feeling on here. That's what makes this place different.

For some reason I seem to have this reputation - looking for a fight - but it's quite the opposite actually. I am glad to hear (read) that this is a different place, where I can draw some attention to a different point of view and different designs, without causing adverse reaction.

Because, most forums are "ruled" by stakeholders of various nature, be it direct commercial (selling their products to DIYers), indirect commercial (passing for an expert or guru and building amps for DIYers who are challenged by the act of soldering or drilling holes or measuring high voltages), or plain vanity (passing for experts and gurus because they've got nothing better to do).

The forum rulers jump on whatever ideas are opposed to their interests, and I am just someone who does not want to let others trash his ideas with impunity. In the end, I get banned either because my presence is not welcome (interfering with interests), or because the only way to trash my ideas and designs with impunity and without any material proof, or copy-cat and butcher and pass as someone's own - is by not "having me around".

Not to mention the fact that in the process a lot of threads get tailored by deleting positive comments, etc.

Thus, it's no wonder people get a certain impression - they are well guided towards that impression. Luckily for me, forum stakeholders cannot delete the contents of my blog

Edit: grammar correction - English is not my native language, but I do have a good command of it, nevertheless

[Paul Barker]

Hi Alex you have better grammer than me and I was born and bread speaking this language but never could pass a writen exam.

I appreciate very much you contribution with your designs to the diy community.

regarding issues in forums I wasn't a witness to the problems you had elsewhere. I believe these occurences usually accompany pride as you hint. the best way to deal with the pride in a poster is to stop rising to his posts for the rest of your life, as though he doesn't exist. Continue talking about your stuff but totally ignore everything he says. Remain humble yourself and keep what you talk about entirely without prejudice or pride.

This baiting and ridiculing goes on in the gas fitters private forum. they occasionally try it on me, but they get bored when you ignore them and pick on someone else. without paying them any attention I continue my discussions as if they had never spoken. those looking for help information and encouragement keep looking and they can see who the troll is and who is simply interested in sharing knowledge.

[Cressy Snr]

Just been having a look at your blog Alex.
Particularly the 307A v2 with the ECC81 driver.

Interesting that you found the 6201 so good.
I have found the exact same thing with a 6201 that Paul sent me.
Superb sounding as a driver in my balanced KT120 push pull amp.

The GEC A2900 is also a fabulous sounding driver valve, from the ECC81 family, but expensive these days.
The zener string for the screen voltage, is something I have wanted to try but was scared off for some strange reason. I mean Bruce Rozenblit uses them all over his OTLs and they don't seem to suffer.

[Alex Kitic]

Another great sounding and high performance tube is the E180CC. This is the driver tube which I mostly use in the RH307A. I also quote it as 5965, but while extremely close as substitute, it is physically different, with higher bulb and large anodes.

The sound of the tube itself, if we may name the phenomenon with the word "sound", is extremely important for the final result. While I design based on electric characteristics, using spice models, once a tube family is defined, the chosen type is crucial to the result.

The 307A is a great sounding tube, and by that I mean in pentode mode. It is hard for me to believe that many great pentodes are dismissed in the role which they were ment to fulfill, being instead used as strapped triodes. I can only assume that designing for pentodes is much more difficult than for triodes: instead of being an advantage, the screen grid becomes a hindrance? When designing for triodes I miss this additional lever to play with.

Getting back on the topic, I only fear the inherent sound of those new powerful beam tetrodes, KT120 and KT150. They could indeed be plugged in my standard RH Universal as KT88 replacements, but they might not reach the sound quality offered by 8417 or EL34.

[IslandPink]

I share your enthusiasm for pentodes Alex - used as gain stages and driver valves . I have used valves like C3m, C3g and EL86 extensively as drivers for DHT output valves eg. 6B4G and 300B . I like the combination of high gain, large voltage swing and a natural-sounding distortion profile .