18 watt Superlite TMB Reverb

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18 watt Superlite TMB Reverb

Post by Bieworm »

Well I am about to build that one. Parts are on their way.
I drew an amp layout where the SL and Tremolo TMB reverb are mixed... well the SL TMB with the added circuit for reverb...
I anticipated for 2 types VVR , and added some extra turrets and jumpers in the B+ line
I know the power supply is missing and the grounds are not connected, but I will do so in the execution...
amp layout 20210706.png
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Re: 18 watt Superlite TMB Reverb

Post by JMPGuitars »

At quick glance it looks okay, I don't have time to look deeper right now. I wouldn't line up the B+ nodes with the ground up top there on the left. You'll notice on my layout I leave space there.

Highlighter verify it with both layout versions, then verify it again against the SL TMB schematic, and separately against my reverb schematic.

Thanks,
Josh
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

JMPGuitars wrote:
Tue 07/06/21 7:00 am
At quick glance it looks okay, I don't have time to look deeper right now. I wouldn't line up the B+ nodes with the ground up top there on the left. You'll notice on my layout I leave space there.

Highlighter verify it with both layout versions, then verify it again against the SL TMB schematic, and separately against my reverb schematic.

Thanks,
Josh
I agree with the space between B+ nodes and power amp grounds. I have to review that area because I want to integrate the VVR circuit on the board . There is a good chance I will stretch the board over the entire length of the chassis and integrate the rectifier on it too
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Re: 18 watt Superlite TMB Reverb

Post by JMPGuitars »

Bieworm wrote:
Tue 07/06/21 7:38 am
I agree with the space between B+ nodes and power amp grounds. I have to review that area because I want to integrate the VVR circuit on the board . There is a good chance I will stretch the board over the entire length of the chassis and integrate the rectifier on it too
Shouldn't the VVR chip be chassis mounted for heatsink happiness?
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

JMPGuitars wrote:
Tue 07/06/21 11:43 am
Bieworm wrote:
Tue 07/06/21 7:38 am
I agree with the space between B+ nodes and power amp grounds. I have to review that area because I want to integrate the VVR circuit on the board . There is a good chance I will stretch the board over the entire length of the chassis and integrate the rectifier on it too
Shouldn't the VVR chip be chassis mounted for heatsink happiness?
Only the chip Yes. I was planning on attaching a heatsink from an old computer inside the chassis , near the rest of the VVR circuit , and put the mosfet there.
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Re: 18 watt Superlite TMB Reverb

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Schematic + layout
The computer blocked... good thing I could still take a picture before restarting...
20210707_094211.jpg
SL TMB R VVR G2 20210707.png
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Re: 18 watt Superlite TMB Reverb

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Btw.. in search for a new guy to print my 3D logos I found someone who also does laser cutting. He has already printed some logos and tonight I'm going over there to engrave some plexi panels I've painted 1 side with gold. Hope that works out well.. that will be very cheap supply then...
faceplate paint execution SuperliteTMB Reverb 2x 132% rev2.png
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Re: 18 watt Superlite TMB Reverb

Post by JMPGuitars »

Bieworm wrote:
Wed 07/07/21 5:13 am
Btw.. in search for a new guy to print my 3D logos I found someone who also does laser cutting. He has already printed some logos and tonight I'm going over there to engrave some plexi panels I've painted 1 side with gold. Hope that works out well.. that will be very cheap supply then...
Lucky! Find out what laser machine he's using. I want one that doesn't cost $$$$$.
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Re: 18 watt Superlite TMB Reverb

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JMPGuitars wrote:
Wed 07/07/21 6:19 am
Bieworm wrote:
Wed 07/07/21 5:13 am
Btw.. in search for a new guy to print my 3D logos I found someone who also does laser cutting. He has already printed some logos and tonight I'm going over there to engrave some plexi panels I've painted 1 side with gold. Hope that works out well.. that will be very cheap supply then...
Lucky! Find out what laser machine he's using. I want one that doesn't cost $$$$$.
I will..
Here's the current panel:
20210707_134735.jpg
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

That guy turns out to be a teacher. He teaches Hi tech machining. That guy has access to everything we can dream about.
He can do my chassis too in the future. Lasercut holes and all.. turretboards.. everything!!!
Josh.. I didn't ask what equipment he uses.. darn expensive for sure.
16256857492688375438796606983283.jpg
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Re: 18 watt Superlite TMB Reverb

Post by JMPGuitars »

Lucky for you!
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

Parts arrived today. Preparing the turretboard for drilling. It's necessary for the chassis layout to do this first...
Found a mistake in my layout. The .1uf where the reverb return goes to the PI is drawn as 1uf.. wow!!!
20210708_202727.jpg
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

BTW.. I'm going for a tremolo tmb reverb with 12AU7 powertubes after this one!!
Just need to figure out the PI for that one.. dunno if the LPT PI will be possible.. so maybe cathodyne will do it?
Or maybe Jack can advize me with some other powertube thing, aiming for 2 to 5 watt
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Re: 18 watt Superlite TMB Reverb

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Bieworm wrote:
Thu 07/08/21 3:39 pm
BTW.. I'm going for a tremolo tmb reverb with 12AU7 powertubes after this one!!
Just need to figure out the PI for that one.. dunno if the LPT PI will be possible.. so maybe cathodyne will do it?
Or maybe Jack can advize me with some other powertube thing, aiming for 2 to 5 watt
Sorry I didn't get to this sooner. My latest hi-fi project is accelerating, just spent most of the day milling and engraving a 1/2" thick aluminum front panel. Still lots to do, but this project will lay the ground work for the next two. I actually have enough high quality stereo transformer sets for six or seven amplifiers. Once they're all built, I'll spend some time fishing. :)

Anyway, I suggested a couple triodes here:
viewtopic.php?f=26&t=25912&p=251188&hilit=6bl7#p251188
For pentodes, I like the 6AK6, but there are literally dozens of possibilities. There are also pentodes like the 5686 that would fall into this power range if a pair were wired in triode mode. Actually, this tube is the sleeper of the year for low powered amplifiers. Very inexpensive here in the states, low filament consumption and a 7.5W anode rating. Manufacturers won't use it because it's a discontinued type, and that keeps prices down.

Any reduced power output stage can be easily driven with the same phase inverter you used in the 1W. No reason to use a LTP unless you just want one for some other reason.

Jack
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

Just looked for those types, but it's nog going to be easy to find them here.
Actually, I'm kinda biased towards the 12AU7 in the previous build. I was very impressed. Might go the double 12AU7 PP in parallel route...
OTOH a pentode would offer some other options like G2 control and stuff...
Dilemma's... but it's a september build, so there is time
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Re: 18 watt Superlite TMB Reverb

Post by TriodeLuvr »

Bieworm wrote:
Sat 07/10/21 3:48 am
Just looked for those types, but it's nog going to be easy to find them here.
Actually, I'm kinda biased towards the 12AU7 in the previous build. I was very impressed. Might go the double 12AU7 PP in parallel route...
OTOH a pentode would offer some other options like G2 control and stuff...
Dilemma's... but it's a september build, so there is time
The 12AU7 in parallel mode will double the output power to roughly 2 or 2.5W. That's a 3dB increase, barely discernible to the ear. The following will do better than that, nearer the top of the output range you mentioned. Do any of these tubes show up on eBay over there? I know they won't necessarily be found at guitar parts retailers.

(One) 6BL7
(One) 6BX7
(Pr) 12B4
(Pr) 6AK6
(Pr) 5686 (in triode mode)
(Pr) 6AH4GT
(Pr) 12BY7 (in triode mode)
(Pr) 6CL6 (in triode mode)
(Pr) 6197 (in triode mode)

You could also use a pair of somewhat larger pentodes in triode mode, maybe the 6AQ5, but with reduced B+ supply voltage for earlier saturation. Not quite the same effect as clipping at the grid, so this might affect the overdrive tone.

Jack
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Re: 18 watt Superlite TMB Reverb

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TriodeLuvr wrote:
Sat 07/10/21 1:33 pm
Bieworm wrote:
Sat 07/10/21 3:48 am
Just looked for those types, but it's nog going to be easy to find them here.
Actually, I'm kinda biased towards the 12AU7 in the previous build. I was very impressed. Might go the double 12AU7 PP in parallel route...
OTOH a pentode would offer some other options like G2 control and stuff...
Dilemma's... but it's a september build, so there is time
The 12AU7 in parallel mode will double the output power to roughly 2 or 2.5W. That's a 3dB increase, barely discernible to the ear. The following will do better than that, nearer the top of the output range you mentioned. Do any of these tubes show up on eBay over there? I know they won't necessarily be found at guitar parts retailers.

(One) 6BL7
(One) 6BX7
(Pr) 12B4
(Pr) 6AK6
(Pr) 5686 (in triode mode)
(Pr) 6AH4GT
(Pr) 12BY7 (in triode mode)
(Pr) 6CL6 (in triode mode)
(Pr) 6197 (in triode mode)

You could also use a pair of somewhat larger pentodes in triode mode, maybe the 6AQ5, but with reduced B+ supply voltage for earlier saturation. Not quite the same effect as clipping at the grid, so this might affect the overdrive tone.

Jack
The ones I can get here is:

6BX7GT ratheon at 22€/pc NOS

Worth a try ? It's SE then? Is the 125A OT a good match?

The only good shop for NOS tubes is this one that sells jukebox parts:
https://www.jukebox-revival.eu/catalogs ... t/?q=+6bx7
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Re: 18 watt Superlite TMB Reverb

Post by TriodeLuvr »

Just for background, the 6BX7 and it's cousin, the 6BL7, have gained favor over the last few years for some hi-fi applications. The 6BX7 exhibits a somewhat lower anode resistance, so it's a favorite in certain applications where that's perceived to be an advantage. Because of this, the 6BX7 often sells for twice as much, even though the difference is really not very significant. I'm only mentioning this because the 6BL7 might be less expensive, if you can find it.

These tubes can be used single-ended, with both sections in parallel, or in push-pull, just like you used the 12AU7. Maximum anode dissipation with both sections operating is 12W, VS 5.5W for the 12AU7. It's a really tough tube, and it can be pushed. Note that filament current is 1.5A. This creates a large electron cloud within the tube that makes it capable of significant peak current capability. That translates to what I call "attack dynamics."

Incidentally, you wouldn't be the first to do this. There used to be a Web page describing a guitar amp that a guy built using a 6SN7 dual triode, similar to the power level of a 12AU7. I think it was push-pull, but not certain now. Anyway, he said the difference when he switched to the 6BX7 was huge, almost too much volume to still be considered a low-power amp.

I wish that page was still up, it would save some time. The main difference is the higher B+ that can be used (VS the 12AU7), and the output transformer needs to be around 6K or 8K, plate to plate. For single-ended, 5K is appropriate, but output power would be considerably less than AB1 push-pull. I believe the push-pull version with one tube can output three to four watts.

Jack
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Re: 18 watt Superlite TMB Reverb

Post by TriodeLuvr »

Here's a link to a couple 6BX7 hi-fi amps. The second one uses a single tube in push-pull. This circuit uses an 8K transformer, and it's a pretty good model of how to build the power amp stage. I would probably use a somewhat higher B+, but it's not critical.

https://www.bonavolta.ch/hobby/en/audio/6bx7.htm

EDIT: Here's a guy who loves tubes almost as much as I do! Note the list on the left also shows the 6BX7.

http://vinylsavor.blogspot.com/search/label/6BL7

Incidentally, if you go SE instead of PP, the 6CK4 is another option. It's a single octal triode rated 12W. Of coursed, there's always the EL84 in triode if you do that, and it draws a lot less filament current. Overall, I think building another amp like the 12AU7 - but with a 6BL7/6BX7 - is the way to go. You've aready got everything else dialed in.

Jack
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Re: 18 watt Superlite TMB Reverb

Post by Bieworm »

Thanks Jack. That's something to really consider on doing
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