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I'm not an amp tech..just making an amateur observation.

The layout appears to be missing some very important information.

Specifically, how do you know the watts ratings for the resistors and the volts ratings for the capacitors and if specific types of either are required?

Do you have schematic?
 

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Discussion Starter #3
i have an original schematic that has some modifications done to it ny others , but its hard to read as a newbee, this one i can understand ok, the above pic like a ceriatone layout
 

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Yes, the layouts are easier to follow and the Ceriatone layouts are very nice. However, the Ceriatone layouts contain the information your layout is missing.

Here is a (random) example where component types and ratings are shown..

CLICK on layout diagram to prevent future vision problems

 

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It's not complete - where are the power tubes, OT and PT?
 

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Discussion Starter #8
this is the best schematic as I am aware of ,,, im using a merren audio ultralinear 100 watt output tranny 4k pri imp and a hammond power tranny with taps for 110/125 volts , ( have the matching pwr tranny from merren that does 540-560 v b+ but going to try the hammand 1st ,hopefully the 110 v tap will get me up to 600 volt b+ I have the main pwr on switch to s toggle between 110v and 125v
 

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Well, afaik there’s no stock 100W Major, if that’s what you’re trying to do it may have been drawn out and even built, but you’re relying on the kindness of strangers (or google foo) for info.

The layout in the first post, as noted, is missing so much info as to be essentially useless, unless you have the ‘key’ that goes with it.

The Marshall schematic, is that supposed to be original but with mods?


Edit! Oh, is schematic post 7 supposed to be represented by layout post 1? If yes, it’s still missing all the power section wiring.

Edit - and the top layout seems to have bias adjust top right, but I don’t see it on the schematic.
 

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Discussion Starter #11
steve @ moratto amps is building it , He is my go to guy for tube amp builds . I dunno what kt88 tube would hold up on 575/600 volt area .I have a few teslavok kt88’s in a few of my marshalls and they seem to work without any issues , but thats at 400/450 volt range . I think nos gec’s are out of the question as they are way too expensive , any people on here have used kt88’s at the higher end of the screen voltage / b+ spectrum ( 600 v)
 

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I built an amp for a steel/guitar player with 2 KT88's running over 600v on the plates (625?) about 10 years ago, never had any issues. 425-0-425 power transformer with solid state rectifier. It was a detuned Trainwreck/Bassman circuit, 1650R Hammond output transformer, 5k primary impedance. You can tell your amp guy if you'd like. I even have a few power transformers yet, I might do another KT88 build but higher gain. The tubes were JJ's. I'm not really a fan of JJ's but these held up well, only one needed to be replaced because it was rattling.
 

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SVT' Classics use 650 +/- volts DC . They do eat tubes occasionally. Anyone willing to put down the coin to build such an amp must accept the inevitable new production power tube failure that comes with the design.
I happen to have an SVT Classic on the bench right now with two blown tubes on it. Tung Sol reissues which are touted as being excellent tubes.
 

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Thanks. he sold me an EP3 a few months ago and mentioned he built amps. I did not realize that he was that well known, great then. (and echoplexes rule lol)
 

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Discussion Starter #19
I built an amp for a steel/guitar player with 2 KT88's running over 600v on the plates (625?) about 10 years ago, never had any issues. 425-0-425 power transformer with solid state rectifier. It was a detuned Trainwreck/Bassman circuit, 1650R Hammond output transformer, 5k primary impedance. You can tell your amp guy if you'd like. I even have a few power transformers yet, I might do another KT88 build but higher gain. The tubes were JJ's. I'm not really a fan of JJ's but these held up well, only one needed to be replaced because it was rattling.



what model pwr trannys were they hammond as well?
 
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