New 36w Build Thread

[GlassTornado]

So I had another good workday yesterday, and I must say that I'm really happy with how everything is coming along, especially after the chassis setback. I got my PT hole cut. This time instead of punching a bunch of holes, i just scored from the 4 corner holes and cut it out with the jigsaw. Both methods end up about the same and require probably the same amount of filing. Cutting the whole thing with the jigsaw is a little less time consuming, I will say. It's just way noisier, but nothing wadded up kleenex couldn't fix. haha.

Will all holes punched and drilled and filed and ready...it was finally time. Started with the necessary grunt work on the heaters. I'm really happy with the way they came out.

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Once I was done with those, I didn't feel like stopping, so I started wiring the PT up. Got the rectifier, the pilot, standby, power, and half of the mains fuse wired up.

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That is that so far, but I get another go at it tonight! I'll keep you guys posted.

[geoff 1965]

neat work! keep it up,
what tubes and speakers are you going to use?

[GlassTornado]

Thanks for the encouragement!

Well so far I have some old brimars that test pretty good for the pres, not sure about power at this point.

For speakers I have a quad of Kendrick green frames that I'm gonna use in both cabs. I've been playing them in a Marshall b cab and they sound amazing.
http://www.kendrick-amplifiers.com/mm5/ ... ry_Code=12
I'll start with them. I'd like to get some nice 20 watt greenbacks for the combo though.

[JMPGuitars]

I'd like to get some nice 20 watt greenbacks for the combo though.

Is there a reason you want greenbacks as opposed to the "greenframe" speakers you have? I've never heard the greenframes, but they look like they want to be boutique versions of the old school greenbacks...

[GlassTornado]

It's more of a "if a couple of 20w greenbacks fell in my lap" I would be inclined to try them, but in all reality the Kendrick's are what will stay in it. They are exactly what you describe them as...boutique greenback, and they sound killer. I just tend to fall down rabbit holes in my head where I can't leave good enough alone. haha

[JMPGuitars]

Hehehe, I hear you. I would never choose celestion over a good clone, especially if made in the US or England. New greenbacks are made in China, and cost MORE. That makes no sense to me. There's a ton of great alternatives including the Eminence Private Jack that I have in one of my amps right now...and I would try 100 other speakers before buying a new celestion.

Of course, if a UK made greenback fell in my lap, I wouldn't argue either.

[geoff 1965]

that's what i like to hear!
the chinese are getting better with the quality of their products but not when it comes to speakers,it's got to be U.K. or U.S.A. made!
Peavey is a good example,they were renowned for good speakers in their amps but then they started putting those crap "blue marvel's" in.

[JMPGuitars]

that's what i like to hear!
the chinese are getting better with the quality of their products but not when it comes to speakers,it's got to be U.K. or U.S.A. made!

Yeah, they're not horrible or anything. But if you're going to outsource to China, I better be saving money. It's crazy to me to pay more for a factory import speaker from China when I can get something awesome and domestic for less.

[geoff 1965]

true Josh,
i'm not knocking the chinese,just stating a fact.when it comes to speakers quality of components count i.e. metals used,cone material,alnico magnets etc and anyone who can weld will tell you the difference between chinese aluminium and U.K. or U.S. aluminium!
sadly it comes down to money,celestion,eminence,peavey even the classic vox amps are made in china "sacrilege" but if they did'nt they would go out of business trying to compete.like you say,why pay more for an import that is'nt as good as the originals! crazy!
what we need is chinese production costs to come up to the same as the U.K. and U.S.A. and it will bring much needed jobs and business back!

[JMPGuitars]

I didn't think you were knocking them. Let's leave politics out of it. I don't really care where anything is made if it's made well. And while Chinese product quality is getting a little better, it's still not as good as US/UK. But even if Celestion was still made in the UK, I wouldn't pay more for their Greenback than an Eminence or US boutique version. Brand loyalty means nothing to me. Every major brand makes good and bad products, and every one of them has consistency issues.

[geoff 1965]

we are drifting away from the subject thread here so come on "GlassTornado" let's see some more pics & info!

[JMPGuitars]

we are drifting away from the subject thread here so come on "GlassTornado" let's see some more pics & info!

We're WAY off topic.

I agree, more pics!

[GlassTornado]

Alrighty! We'll get back on track here. Sorry for the delay. Band's been recording, and we've had some shows getting in the way of my building! haha.

Let's see, where were we:
Got all the connections hooked up on the power tubes. I prefer individual 100ohm resistors for the b+ on each socket rather than 1 larger single. It also works out with me using a 18w sized board because I chose to do bias cathode resistor/cathode for the two pairs of tubes instead of one for all four. I also moved the four 8.2k grid stoppers directly on to the sockets because there wasn't room on the board either. This is the setup I have going on my currrent 36w and it does just fine.

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Obligatory cliff jack wiring pic

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After wiring the OT primary and secondary and the output jacks.

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Another angle of the cable routing as it starts to build up

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I like the next picture because of what it becomes afterwards...but this is the board with 90% of the leads soldered on it waiting to be installed.

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And now for one of my shining achievements of this build. I decided to lace the two larger groups of wires instead of just zip tying. It was a bit of a pain at first, but I'm 100% stoked of how it came out.

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This is last of my progress as of 10:30 last night. Actually I have the whole "pot side" of the board done except for the two caps on the trem side pots.

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I know it's a lot, but I would work a little, and take pics, and then they've just build up. I'm getting pretty close though. Hopefully I'll get to light some filaments by next weekend!

[geoff 1965]

you're attention to detail with the wiring is superb! makes mine look like a bowl of spaghetti!
can i ask what gauge & type of wire you used,is it ptfe? also did you use single core or stranded for your heater supply?
keep it up! if this amp sounds as good as it looks it's going to be awesome!

[GlassTornado]

Thanks for the kind words! On this one I've been really keeping "measure twice, cut once" close to my heart. Plus I got a little jealous...I have a buddy that has done some NOS style builds of a 45/100, Black Flag 50, and a 12,000 series Super Lead, and his lead dress and routing is tough to beat. So this one I wanted to see if I had the hand and patience.

As far as the wire I'm using it's the 22awg that Valvestorm.com sells. The technical info they have for it is: 22 AWG UL Style 1015 VW-1 105°C 600 Volts CSA TEW 105°C Wire

All the colors I'm using is just from their plexi amp wiring kit: http://valvestorm.com/Products/Wire

So the heaters are also 22awg stranded. But all the wire is pre-tinned, so there's no stray whiskers when you strip it.

[JMPGuitars]

Very nice work!

The wiring does look really good, but the heater wiring could create a noise issue (though it might not). For best results, heater wires need to be tightly wound, even up to the point of contact on the tube sockets.

According to Valve Wizard, apparently almost everybody supposedly wires the preamp tube heaters wrong. Here's what he says about that: http://www.valvewizard.co.uk/heater.html - scroll down to layout / lead dress and he shows 3 examples of preamp heater wiring.

I haven't tried his "better" way yet, but I will on my current build when I have time to continue with it.

BTW- I love the laces. Your patience and attention to detail on this build is pretty awesome.

[geoff 1965]

Thank's for the valvestorm link glasstornado!
i'm impressed with their wiring kits but i'm U.K. based so it depends on the postage costs.the valve wizard site Josh posted has some good info as well and like Josh i'm tempted to try the "over tube" wiring method next time.there's a lot of different methods i.e. look at the fender blackface amps where the heater supply loops over from tube to tube and does'nt touch the chassis!
mine is a mess to look at "i lost patience" but ironically has no hum!
another way of reducing noise is to switch phase between the el84's,have a look at this "ampmaker" layout

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[WilliamBrama]

Awesome job, !

[GlassTornado]

The wiring does look really good, but the heater wiring could create a noise issue (though it might not). For best results, heater wires need to be tightly wound, even up to the point of contact on the tube sockets.

I can totally see the benefits of doing the heaters that way for sure. From an EE (which I am not) perspective, I totally understand the benefits of it. The twisting of the wires is to eliminate hum and if you leave the ends untwisted near the sockets, it's essentially un-doing some of what your twists were doing. On the other hand there is a bit of the artist (which I am) that thinks there's a happy medium between ideal EE and elegant work. The "Marshall way" as I would put it might have it's flaws, but it's also what I like to see, I guess. I've also never had a hum issue with it up to this point. Nothing more/less noticeable than any other amp I play. My '77 Super Lead looks like they flopped the wire over once and called it good! hahaha. I would be very curious as well to try that method on a build to try and get some comparison. Is the juice worth the squeeze kind of thing. Thanks for the link. I tend to land on that page when I'm in the middle of builds and always forget about it.

another way of reducing noise is to switch phase between the el84's

The phase switching of the el84's is super interesting. I guess it makes a lot of sense that switching phase would cancel out potential noise. I feel like my other 36 watt would be a great test bed to go back and try both of these methods out. I've been playing it for a long time now. I know how it sounds and what it's noise floor is like. I'd be interested in pulling the heaters and re-doing them with twist to socket and phase swapping on the power tubes. This might be the first time you've ever heard someone say they WANTED to re-do heaters, folks!

Thanks again for all the helpful advice and kind words. I have two connections to finish the preamp sockets tonight. Oh, and I somehow forgot to order the 1.5k resistor for the mains cap, so the waiting game has begun...again. haha!

[GhengisKahn]

Morgan Jones in his book "Building Valve Amplifiers, " also recommends the top down filament wiring. I have used it for some time on many amps and it seems to work the best, keeping all unwound leads to the tubes short as possible. Some amps seem to have hum problems and some less so, some of it is tubes, maybe sometimes it's the transformers, but with a grounded center-tap on the filament winding, it's usually not much of a problem. EF86s are almost always more hum prone, especially when used as the 2nd stage in a 3 gain stage amp with no cathode follower. EF86s are noisier in general, it seems, but they also have gain and tone all their own and at volume, the hum and noise are completely swamped by the signal, so it can be worth it.