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Audio and Video Talk
Valves / Vacuum Tubes
Anyone seen one of these? (Vintage naked pics)
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<blockquote data-quote="Ampdog" data-source="post: 772171" data-attributes="member: 144"><p>Forgot about this thread.</p><p></p><p>Be careful with the OPT. A gap in the core is mandatory for singe-ended operation to prevent the transformer from saturation, but not as big as the model shown. One usually put some paper in there, rough guess would be a gap of about 0,3mm.</p><p></p><p>I forgot to mention, some student friends of mine helped with building these, at, I believe, 5 shillings per chassis! The year if not mentioned previously, was about 1956-7. I was in some competition with Procter with a similar amplifier called "Piekanien", parts cost some ?7-10, sold for ?15-00; which he didn't like, but I could not go into 'production' being a student and having to spend some time to swot. [Saying in my time was: "Engineering is a 5 year (in the case of U.S. then) course, of which the first 6 years are the most difficult".</p><p></p><p>Nostalgia. [OT; perhaps to revive the Piekanien seeing as how S.E. EL84s are in again - but certainly not for R30 - or with the present Ex.R., more like R330; still not!]</p><p></p><p>But as asked, how did you fare, Afroaudio?</p></blockquote><p></p>
[QUOTE="Ampdog, post: 772171, member: 144"] Forgot about this thread. Be careful with the OPT. A gap in the core is mandatory for singe-ended operation to prevent the transformer from saturation, but not as big as the model shown. One usually put some paper in there, rough guess would be a gap of about 0,3mm. I forgot to mention, some student friends of mine helped with building these, at, I believe, 5 shillings per chassis! The year if not mentioned previously, was about 1956-7. I was in some competition with Procter with a similar amplifier called "Piekanien", parts cost some ?7-10, sold for ?15-00; which he didn't like, but I could not go into 'production' being a student and having to spend some time to swot. [Saying in my time was: "Engineering is a 5 year (in the case of U.S. then) course, of which the first 6 years are the most difficult". Nostalgia. [OT; perhaps to revive the Piekanien seeing as how S.E. EL84s are in again - but certainly not for R30 - or with the present Ex.R., more like R330; still not!] But as asked, how did you fare, Afroaudio? [/QUOTE]
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Audio and Video Talk
Valves / Vacuum Tubes
Anyone seen one of these? (Vintage naked pics)
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