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Re: My new build ,high volyage readings

Posted: Sun Jan 17, 2016 6:39 pm
by fixer2
Well it now works great and the sounds are great it is more of a cross between 3 different early Marshalls that all have the same turret board lay out ,nice so now what to do next what would be a good Idea for me to correctly advance my learning I dont want to bite off more than I can do I want to learn as I go along.But Thank you all again.

Re: My new build ,high volyage readings

Posted: Mon Jan 18, 2016 7:06 am
by neikeel
fixer2 wrote:Well it now works great and the sounds are great it is more of a cross between 3 different early Marshalls that all have the same turret board lay out ,nice so now what to do next what would be a good Idea for me to correctly advance my learning I dont want to bite off more than I can do I want to learn as I go along.But Thank you all again.
Practice your soldering, plan ahead, try to keep the wires straight on components and plan your next build. I think a JMP50 with EL34s is the most versatile.

Re: My new build ,high volyage readings

Posted: Mon Jan 18, 2016 2:28 pm
by danman
I think you would have an easier time doing a standard Metro style kit with turret board construction instead of the Tube Depot kit with it's pcb and circuit modifications they include. Like Neikeel mentioned, a JMP50 would be a great amp to build. Check out "Valvestorm.com" for everything you may need and you can use the Metro instructions found online. If you want to go in a different direction, a Fender 5e3 Tweed Deluxe also makes for a fun build.

Re: My new build ,high volyage readings

Posted: Mon Jan 18, 2016 2:54 pm
by DG45
To be clear, the Tube Depot kit isn't PCB based. It is turret board construction.

Re: My new build ,high volyage readings

Posted: Mon Jan 18, 2016 4:10 pm
by danman
You are correct, it is turret board construction. I was thinking of one of their other kits.

Re: My new build ,high volyage readings

Posted: Mon Jan 18, 2016 8:25 pm
by fixer2
A JMP 50 does sound good I did not see it there but I will check out and I guess you buy each part at valve storm and put together a kit sounds good .Yes being neater on my wire lay out would have made the tracing of wires a lot nicer .Any books or dvds would you guy think of be good were did you guys get your learning from ?

Re: My new build ,high volyage readings

Posted: Tue Jan 19, 2016 4:17 pm
by danman
At Valvestorm you have the option of choosing various items for your build. Most of the Marshall 50watt amps are very similar and the only difference is the choice of a few different component values. The B+ voltage did change over the years and you can buy different PT's that will give you the range you are shooting for. I believe that Metro based their kits on the 1968/69 Plexi models with B+ around 450v. There is a great set of instructions for the old Metro kit http://www.metroamp.com/downloads/50_WA ... CTIONS.pdf that you can use for the build.

As for getting neater with your lead dress, just hang around here and check out all of the great build pics over the years. There are numerous build logs here on the forum that you can check out. Pay special attention to how the wiring has been routed in some of the nicer builds. Main thing is to take your time, keep your wiring as short as possible and plan ahead. Don't rush because it is to easy to make a simple mistake that can take hours to figure out.

Re: My new build ,high volyage readings

Posted: Tue Jan 19, 2016 4:24 pm
by danman
Here is the link..http://valvestorm.com/50watt%20Kit for the 50 watt kit. You will need to do some research to decide if you would prefer the 1986 (bass) circuit or the 1987 (lead) circuit. Either way it is only a few different parts between the two circuits.

Re: My new build ,high volyage readings

Posted: Sat Jan 23, 2016 9:53 am
by fixer2
Just thinking should I re bias the tubes after using the amp for 8 , 10 hours of playing because all of it is new ? And DG 45 what did you bias your tube depot build to more or less what they said to.,What tubes are you using ,the jj s .I did mine in around 32 mavolts ally like the sound,so like I said I was just thinking thats all.Thanks

Re: My new build ,high volyage readings

Posted: Sat Jan 23, 2016 12:27 pm
by DG45
I run them a little hotter than 32. With the GZ34 rectifier, I biased at 35mv (the hotter tube) with 450v on the plates. So, around 65% dissipation. If I recall, it's a little hot with the silicon diodes. I tried to find a balance in case I lose the GZ34 and have to switch to the silicon diodes.

I'm using JJ EL34. Also JJ's for V1 and V2 and a Sovtek LPS for the PI (V3). And a JJ GZ34 (I have a Sovtek 5AR4 as a spare).

I probably should have checked bias after several hours of playing time but I didn't pull the chassis for at least a couple of months after I first built the amp. When I did, bias was still holding. I think I just had to bump it up around 1mv. I don't know what the "rules" are regarding whether bias should be checked every so often. If I pull the chassis on an amp, I usually check it. With tubes that are matched and burned in by a reputable dealer, it probably shouldn't be necessary once you bias it the first time. But with todays new tubes, it probably isn't a bad idea to check now and then.

Re: My new build ,high volyage readings

Posted: Sun Feb 28, 2016 6:11 pm
by fixer2
I never did ask why the sovtek LPS for v3 how does it sound differnt ,and how would bias 2mv higer make it sound it would break up sooner right but I am very happy with mine . I was looking at some of the remakes of mullar tubes and thinking are they worth the price.

Re: My new build ,high volyage readings

Posted: Mon Feb 29, 2016 8:03 am
by DG45
fixer2 wrote:I never did ask why the sovtek LPS for v3 how does it sound differnt ,and how would bias 2mv higer make it sound it would break up sooner right but I am very happy with mine . I was looking at some of the remakes of mullar tubes and thinking are they worth the price.

The LPS is quiet (as long as you get a good one) and I like the way the amp breaks up a little better with them in the PI. But it's pretty subtle. I don't think they are as "hot" so maybe that's why. But someone suggested trying them in the PI for a different amp of mine several years ago so I just stuck with them, they are cheap and I haven't had any issues with any of them. But I only use them for the PI.

For the output tubes, again, a 2mv difference, say 32mv versus 34mv is probably hard to hear. I think, in theory, the output tubes would break up a little sooner biased hotter. But in my case, the tubes aren't perfectly balanced, they are off by about 2.5 mv or so. So biasing the one at 35 means the other is under 33. Sounds good and I'm not worried about the 2.5mv difference. Too cold and the amp just sounds lifeless. I think experimenting between 60% and 70% dissipation is a safe bet. Just make sure to also check the bias with the silicone diode rectification if you installed that option and think you may plan on using it. You may have to find a balance.

Re: My new build ,high volyage readings

Posted: Thu Mar 03, 2016 8:57 pm
by fixer2
thanks for the info I will do some testing other tubes some day but for now this amps sounds great better than my stock marshall vintage modern that I got really cheap used which is a nice 50 watt combo but this amp sound is more there .Thats why for my self I want to build a plexi when I can no rush.

Re: My new build ,high volyage readings

Posted: Thu Oct 27, 2016 10:53 am
by fixer2
Hi I have two questions I have been reading in a 2012 post here on van halen tone and they were saying to change the plate res on v1 from 100 k to 22/k were is this fesistor is it the first one on the board like t1 and t2 right next on the same turrets as a cap I would like to put it on a switch or may be switch a lesser value going from this resistor to make my already flexible amp into more if someone could highlight this resistor on the tube Depot layout and put it on this forum would be great thanks

Re: My new build ,high volyage readings

Posted: Sat Oct 29, 2016 9:44 am
by fixer2
can any one show me on the tube depot jtm 45 plus layout picture where the plate resistor isI think that it is the first one theat shares the turrets t1 and t2 with a cap and is right now 100 k I would like to know if I could put a resistor of an another 100k in seri with it on a switch to then have it to be able to choose either what I have now or add more for more gain at a flick of the switch .Any replys would be great to hear any Ideas