Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: adamG on July 22, 2016, 03:53:17 am
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Hi Guys,
Recently, I assembled Sluckey's project November 18W.
This time I reduced tube rectifier for SS one.
Previously, Umble style OD stage was added, but now I thought to myself to apply hot switch. This idea came out much more simple and better sounding solution.
I feel that the amp is really great now! I am at least delighted. As usually, I applied polypropylene caps, carbon composition resistors.
I can not describe its valor, but now the amp has everything what it suppose to have. It sounds vintage. It gets me to the field of oldies but goldies rock bands.
There might be a question how to increase hot switch gain? It's not a pressing need ,but I think It might be some better.
Thank you Sluckey for this project!
Regards,
Adam
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That looks fantastic! Thanks for sharing.
With respect, Tubenit
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WOW !!!
:bravo1:
Looks really Cool
Franco
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That really looks professional! I got the idea from ax84.com. Credit really goes to Randall Aiken and the guys from www.ax84.com (http://www.ax84.com).
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Thank you very much for words of encourage.
I know it sounds not humble, but with this amp I've received something...
To me I feel that I reap the fruits of my labor, because I'am not an electronic man. I am newbie on this field. That is thousands hours of studying and lots of efforts. You know that , as well.
This forum gave me a lot of knowledge and your support.
Thank you.
But, how about in increasing gain on hot switch?;) Any ideas?
Thank you in advance.
Regards,
Adam
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Can you show us a schematic of your hotswitch mod? Then we can provide specific suggestions to increase gain.
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Sluckey,
There's the schematic attached at the very beginning of my topic (above the photos).
Please, have a look at.
Regards,
Adam
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You can experiment with the values in "red"
With respect, Tubenit
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Tubenit covered most all the ways to increase the gain. I was gonna suggest to just short out that 150K connected to the level pot to see if that gets you too much gain. If so, then use a smaller resistor as tubenit suggests.
One more way to increase the gain would be to increase the size of the 100K plate resistor. I'd try 150K, 180K, or even 220K.
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The 250K "Trim" pot (loading a 1Meg first gain pot!) could be 500K or 1Meg easy.
Modding to higher gain could give you a howling uncontrollable monster. Since it is good now, be very careful with your changes. An external boost pedal may be a smarter choice.
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Wow! That is a very nice build.
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Yes, very, very nice! :bravo1:
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The 250K "Trim" pot (loading a 1Meg first gain pot!) could be 500K or 1Meg easy.
Modding to higher gain could give you a howling uncontrollable monster. Since it is good now, be very careful with your changes. An external boost pedal may be a smarter choice.
I was going to say the same things as PRR but also same for the pot after the plate - make it 1M too. The cathode resistor & bypass cap is already "giving her all she's got cap'n". The 220K load resistor is another however it could be a good idea to instead use two 100K load resistors (called split-plate load) and take the plate signal from between them which will cut down your already high signal voltage and allowing you to crank that pot afterwards. They form a voltage divider like what's created with the 150K & pot. If it's too bright for OD purposes use a high value grid stopper resistor on your socket this feeds and/or a small cap on the upper 100K load resistor to taste.
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Looks great. Where did you get chassis?
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Thank you guys...very much for kind words and tech.hints!
I'll try what you seggest.
I'm not a guitar player. Therefore ,I wouldn't publish the amp's sound samples. Sorry!
Best regards,
Adam
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Where did you get chassis?
All of my chassis are made by myself.
First, I design amps' arrangements in CAD program. Then ,they're ploted on paper, glued to aluminium plate, cut out, drilled, bended, welded and paited. Pretty long journey :smiley:
Regards,
Adam
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I've got to get a metal break sometime. Ha.
What's your painting method? Looks great
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What about the face/back plates?
All of my chassis are made by myself.
Great job on the chassis too! Double> :bravo1: :bravo1:
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What about the face/back plates?
Plates? I'm not that smart. They have been laser engraved by local workshop in my city.
With chassis and trannies by myself I am free to choose what I need and like to build :smiley:
That philosophy took me several years, but I really love that amp hobby.
I am too weak to be a musician, so...I express myself in this way.
Thank you for words of encurage.
Best regards,
Adam