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#11
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Re: The next phase:
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Yeah a bit of research seems to throw up that the ECC82 was a bit of a "Do it all" valve, used for frame and timebase oscillators etc and driver stages. The ECC88, I already had figured as it was developed as a VHF RF amplifier, giving better performance than it's predecessors. That they work well as an audio valve is a bonus, however I am given to believe that Microphony can be an issue as with a lot of RF valves as it wasnt so much of an issue in the rf and if stages of a radio/tv set. Some seem to be more prone than others. In a line level preamp I wouldnt expect microphony to be such an issue, its microphone and the first amplification stage in a phono preamp where I imagine the issues would be more apparent. The trouble is, valve types can be a bit "marmite" some love certain types, some don't like em so I say go with what you prefer cos that's the right one. The ECC81 seems to be a case in point, I think its a great valve in a lot of applications but there are a lot who don't rate it. Shame as generally speaking they can be very cheap for good NOS. ECC83.............. I have tried many types and in the end I think you have to go a long way to beat the JJ ones as supplied in the WD kit. I got hacked off with "NOS" mullards after sepnding a bit in the past on them only to find that a lot had a tendency to either fail (heaters) or go noisy/microphonic. I think theres a lot of "NOS" touted about that were reject quality back in the day. Andy. |
#12
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Re: The next phase:
Hi Andy and all, Andy and I spoke on the phone about **** valves, and other things, but if you get the chance to try some Groove Tubes, Andy, you may be pleasantly surprised, didn't get the opportunity to mention the GT on the phone, cause I dare not interrupt you, . BOB
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#13
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Re: The next phase:
It was great for Nigel (vinylspinner) and I to meet up with Andy briefly on Sunday. It's always good to put a face to a name on the forum. Nice to meet you, Andy and continued good fortune with your current project.
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#14
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Re: The next phase:
Thanks Greg . Bob Sorry if i was off "on one".
Well things have ground to a halt again. Partly because my new Mains transformers for the EL34 project are just as noisy as the originals and are on their way back to the manufacturer for a good coat of "looking at". Very frustrating. And you may have noticed in the news that ceratain parts of the country got a tad moist over the weekend. So been a bit involved checking up on ma and pa etc. Luckily they werent flooded but were stranded on an "island" for a short while, a lot due to bridges being closed until declared safe to cross. And there's us looking to move back over there........... at least i know where to avoid now even more so than before. A. |
#15
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Re: The next phase:
Hey Andy, no offence meant at all, sorry to hear about all the bad news up north with the flooding, we used to have a problem with a main sewer in the road popping a lid off just outside the bungalow, in heavy and prolonged rain, four property's used to get hit, but if we kept the door shut it did't do too much damage, all sorted now though, , bad news about the transformers, hope that you get it sorted. BOB
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#16
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Re: The next phase:
None taken Bob.
Busy times now but i will get a look at the casework and do some "dry fits" of hardware and see what i can fit in and still get my "sausage fingers" into the job. I have a feeling I may still revert to a separate PSU if I feel its too cramped and I can't get decent distance or a screen from the mains transformer. The case looks superb, should look good on the rack. A. |