First Amp Layout Design, Need Input and Advice

[rocket88]

hey guys, i'm hope someone could help me out a bit. after working off of pre-existing layouts for a few builds, i decided try my hand at making my own layout, obviously using the schematic to work off of. i've been doing a lot of reading on the forum here for a bit and it gives me some confidence to work on a layout. it's not really in the same vain as all the hoffman amps, cause for some reason i like the idea oh having the the parts "floating" and a few smaller sections that can be positioned around the chassis, and it helped me try to keep as many wires going to the tubes on one side, and other connections on the other side.

oh, the one thing that's different from the schematic is the rectifier diodes. i changed it to 2 sets of 3 parallel 1n4007's based on something i read about a replacement for the stock ones which are labeled MR1-1600. no one seems to know a part number for them, and that in what i found having parallel diodes is more efficient and reliable.

i know i don't show the wires going to the tubes or the transformers and used numbering to do so. DIYLC doesn't have a transformer, and when i put in the wires to the tubes it was harder for me to follow so i tried the numbering. hopefully that doesn't cause an issue for anyone trying to trace it and help me out. i already tried tracing it back to get the schematic, and it all seems right to me, but idk since this is my first layout.

i'm a little unsure if the layout is correct, and was hoping with all the experience here i could get someone to look it over, and let me know if there are any errors. i should also say that i build and design effects pedals on vero all the time, and this is the first time i've done anything on turretboard. believe it or not i actually did this the old school way on graph paper, then transferred it into DIYLC to make it look nice and pretty. if anyone has good advice on designing layouts i'm all ears and would really appreciate it.

if i got it right, i can get working on some other amps that i've always wanted, but either can't find, can't afford, or can't find a working layout for.

anyways, enough of my babbling. it's a first gen sunn model t

thanks in advance for any guidance. btw, what is the program people use to make their layouts that that has graphics of all the components (tubes, jacks, transformers, etc.) like in the hoffman library?

[DummyLoad]

btw, what is the program people use to make their layouts that that has graphics of all the components

M$ visio. 

--pete

[sluckey]

Your input jacks are a little different from the schematic but they will work. You need to swap the green and cyan wires on the Master Volume pot. I didn't spot any other electrical errors.

I see some layout issues I'd change. Those .25µF coupling caps between the PI and the output tubes will be huge. I doubt they will physically fit on your layout. You have the tone stack components sandwiched between the bias supply and V3 PI components. I would move all the TS components left so they will be next to the V2-8 resistor/cap.

It's hard to get a sense of how this will actually lay inside a chassis because the size of the components are not scaled properly. But it all looks a bit scattered to me. This amp circuit is so similar to a Plexi circuit that I would just start with a Plexi layout and adapt that to fit your schematic. Most all components would fit neatly on one board.

[Willabe]

Welcome Rocket 88!   

Well, not to discourage you, but that's a pretty big amp to do your 1st scratch layout on. 

A smaller amp, lower wattage/less tubes would more than likely be easier to tackle on the 1st try to get up and running.

Bigger amps with more tubes will have a larger chassis and longer wire runs that could be a problem. 'Lead dress' will be more of a factor with longer and a few more wire runs to rout. 

We don't know how many tube amps you've built but a scratch layout can be a large undertaking in new territory for sure.     

For a 1st build guys often start with an amp like a Champ, ~5w/3 tube(1x12AX7/1x6V6/1x5Y3) or a tweed Deluxe, ~15w/5 tube(2x12A_7/2x6V6/1x5Y3) with a pre punched chassis and pre made/copy of their Fender eyelet/turret board and still have problems with the lead dress.

We've had other guys post here about a 1st scratch build of those 2 amps (or something similar) and sometimes have the same 'lead dress' problems and/or other layout problems. Even if they had a few to several successful builds under their belt already.

Reading is very good depending on who wrote it.       But actual hands on experience will tell the true story, in showing any flaws/mistakes.

[Willabe]

oh, the one thing that's different from the schematic is the rectifier diodes. i changed it to 2 sets of 3 parallel 1n4007's based on something i read about a replacement for the stock ones which are labeled MR1-1600. no one seems to know a part number for them, and that in what i found having parallel diodes is more efficient and reliable.

Just go with the 1N4007's, they are good for 1kv PIV. So 3 is series = 3Kv PIV. You probably only need 2 in series in each leg.

[rocket88]

first and most importantly for the help thanks guys.

sluckey, i figured the size of some of the caps are way off, in DIYLC i would have to go in and change the sized based on the datasheets, and to be honest i was a little lazy to do it to be honest. not to mention that i really wanted to re-due it using the same software are the layouts i've seen used here.

Willabe, believe me i completely understand. i've built a few small amps, and done some repairs before and all has been alright. not sure if this will be the first big amp i'll build, as i'm really a bass player, and have always wanted a sunn 2000s, but this is the first amp layout i've designed. so far i've been reading a lot of stuff posted here, the music electronics forum, and as far as books electronics for guitarists, but have been looking at a few others before tackling a bigger project. hell, the death cap is reason enough to approach this with as much knowledge as possible. i do usually jump in to things full on. out of curiosity shouldn't some of the lead dress issues be fixed with using shielded cable in certain areas? without a doubt experience will be key, and really make my layouts better. btw, any other good sources for information, books, sites, etc?

sluckey, cool to know the jacks will work, i just did that because it was the best jack i had in DIYLC, i figured i would correct it when i did it in the other program. if i'm not mistaken the input jacks are 3 lug mono, normally closed, right? thanks for the suggestions about how and where to move certain components to make things flow better and better posistions for parts. i literally made the layout by moving across the schematic. i see how i can take the V3 PT components and move them completey off that section and move the TS over. i didn't realize the sunn and plexi were that similar other then they were really tweaked bassmans. to me the sunn always seemed to eat the plexi, and has gain that can destroy the world. lol

thanks DummyLoad. i'm looking at getting it right now. does it have the components in it already or do i have to get it somewhere?

[DummyLoad]

> thanks DummyLoad. i'm looking at getting it right now. does it have the components in it already or do i have to get it somewhere?

most of what you see (sockets, parts, etc.) are custom symbols. post a request for them and those here that have some to share will hopefully help you out and and post what they have.
we can upload .VSS files to the forum, unless the stencils files are over 800K. .VSS are visio stencil files.

grab what i have here:

--pete

[rocket88]

awesome pete. thanks so much. i've got to get the hang of using visio, but it looks fairly easy, and the components you put up for me to grab are awesome. i see a massive difference in size between some of that caps as well, so it makes perfect sense that some of the spacing i have will be way off and need to be adjusted to make it all fit right.