Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: bruno on September 08, 2010, 12:26:33 pm
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Another look at this circuit, which I've been curious about... I'm trying to understand that the gain structure/arrangement/topoly and tremolo circuit could be for this amp, as I really like the videos spread all over the internet.
I'm trying to trace something similar out, and go for a build, using a set of vibrolux transformers, however I'll be using 6l6s. I'm going to take a good look at the photo posted and see what I can come out with, any ideas would be quite welcome.
This amp and the lil'elvis share the same pre amp and tremolo. Here is a better look at it's interior:
(http://www.premierguitar.com/Stream/StreamImage.aspx?Image_ID=5C022514-7F2C-4AA7-A5B5-512CAA9564E6&Image_Type=image)
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I can't really make out much from the photo, but I see some caps in the first part of the board, that kind of make me think that despite the single tone control the amp works with a full tmb equalizer, with fixe positions for some the values... so maybe the pots controls treble only!
Tremolo seems to connected to the 220k resistors after the phase inverter. And to the power rail too.
Also I think it uses a cathode follower but I can't make it out, if it doesn't use a cathode follower, then the 60s vox pacemaker, might be a very close arrangement for this amp, altough it is still one pre-amp tube short, but those two triodes could have been used for a lot of things, such as:
-extra gain stage before PI
-cathode follower on the tremolo
-two triodes in paralel at input
-extra switchable gain stage
-etc.
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Have a look at
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I had seen that one... but he doesn't really go into any sort of detail!