I got a chassis together for a quick 6G2 using some inventory I have around here. So far it looks like a Weber 100mA PT w/ I think 330 and 300V taps, and a BF Deluxe OT. I fear I have already strayed from Leo's way but also in the spirit of Leo I'll use what I have!
Anyone have any tricks they like to do with these? I figure I'll put the NFB on a switch, or the 2nd stage cathode. I imagine the effect would be similar.
Brown Princeton
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Smokebreak
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Brown Princeton
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Smokebreak
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Re: Brown Princeton
got the rest of the bits drilled and some parts assembled. My PT cutout was a smidge small so I had to file a bit.
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Smokebreak
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Re: Brown Princeton
I've got a 5V4 I'll use for the rectifier till I find a 5Y3. Surely I've got one of those around here somewhere.
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Smokebreak
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Re: Brown Princeton
Heaters. I also just realized I forgot this amp isn't cathode biased. I hastily threw a pre made board to an order but forgot the bias board . Oh well! So..I'm still gonna put a bias pot here with the tremolo and all, and take the supply from the HT
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JazzGuitarGimp
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Re: Brown Princeton
You actually drilled holes for the pots' anti-rotation pins? Who does that?! 
I have a feeling you're going to love this amp. If I recall correctly, the tremolo circuit in this model is very highly regarded. Especially considering it's a bias-wiggle, and not the 5-triode Harmonic Tremolo.
I have a feeling you're going to love this amp. If I recall correctly, the tremolo circuit in this model is very highly regarded. Especially considering it's a bias-wiggle, and not the 5-triode Harmonic Tremolo.Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture
Printed Circuit Design & Layout,
and Schematic Capture
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Smokebreak
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Re: Brown Princeton
Well the last thing I want is the damn pots moving around 
I'm looking forward to seeing how this trem reacts to distortion !
I got sidetracked and started making a board
I'm looking forward to seeing how this trem reacts to distortion !
I got sidetracked and started making a board
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JazzGuitarGimp
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Re: Brown Princeton
That 1K5 resistor looks to be worth about 800 watts by today's standards!
Lou Rossi Designs
Printed Circuit Design & Layout,
and Schematic Capture
Printed Circuit Design & Layout,
and Schematic Capture
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Smokebreak
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Re: Brown Princeton
Indeed it's a bigun! But it's only a watt or two
Re: Brown Princeton
I did a budget 6G2 build in a Super Champ XD carcass. Really dig this amp. Used SS rectifier due to the PT I had. Added adjustable negative feedback, switchable first stage cathode cap, and a large grid stopper on the PI. Build thread and schematic here...
http://ampgarage.com/forum/viewtopic.ph ... highlight=
Turned out to be a great little amp!!
http://ampgarage.com/forum/viewtopic.ph ... highlight=
Turned out to be a great little amp!!
Deric®
Re: Brown Princeton
I built a 6g2b into a Blues Junior style cabinet on a chassis I had made custom to fit. Had to reverse the circuit due to speaker location, but mostly stock otherwise. I did change the caps to slow down the term a bit. And of course mine has a 12" speaker (JBL K120).
One of my favorite amps. It lacks a little brightness, but if you go with it, the warmth is very sweet. Wonderful cleans, and the breakup is compressed just enough. Lovely.
Hope yours comes out great!
One of my favorite amps. It lacks a little brightness, but if you go with it, the warmth is very sweet. Wonderful cleans, and the breakup is compressed just enough. Lovely.
Hope yours comes out great!
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Smokebreak
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Re: Brown Princeton
Thanks for the reports guys! Superchump! Very cool. I was just gonna ask about voltages. So 360-370 plates and ~180 1st stage? Yea those Fender voltages seem impossible, if not optimum.
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Smokebreak
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Re: Brown Princeton
Got the board done. I tried to use as many different brands of components as possible 
I've got the NFB as a 50K trim + 25K resistor to tweak, and I mounted an extra eyelet to put the whole thing on a switch. I keep telling myself not to add a bunch of switches and whatnot but it's inevitable I think
Now i've got to figure out how I'm gonna do the power supply stuff.
I've got the NFB as a 50K trim + 25K resistor to tweak, and I mounted an extra eyelet to put the whole thing on a switch. I keep telling myself not to add a bunch of switches and whatnot but it's inevitable I think
Now i've got to figure out how I'm gonna do the power supply stuff.
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Smokebreak
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Re: Brown Princeton
What a cool lil amp. I finished yesterday and spent the day tweaking then listened again today.
I knew it was gonna be bass heavy, so i tried to account for that before I even built it. On fire up, cleans were beautiful. I started with a 5Y3 and had around 370V plates. I fiddled with the pre voltages and actually liked them better above 200 at the first ax7 plate. The only issue with this amp is that it sounded great from 1-9 on the dial. It just fell apart when cranked, and when I hit it hard. It just sagged and compressed way too much for my tastes, and the flub just took over when you hit it.
I tried a bunch off different things. First I put in the smallest value 1M pot I could find, around 870K. Then dropped all the couplers a bit and 1st catrhode. Of course that cured it but then the cleans suffered. I made the grid leaks 100K for the 6V6s. That actually helped the most, but I still wasn't 100% happy. I could tighten it up by increasing the NFB, but then everything got a lil boring. Finally I put a resistor from wiper to ground on the volume pot, and boom, there it was. Then I crept back up on all the other things I reduced.
Now I can crank it, sit right in front of it, and bang away. It's a good volume. I ended up settling on a 5V4, and actually like the higher voltages across the board, just for the clarity. I think things settled around 380 or so on the 6V6 plates, and 230 on the first stage.
I think if I were to put another pot on front the soul control would be a good one. For kicks I put a cut-type control across the cathodyne, in the usual spot. It didn't need it but I was curious, and though it worked, it kinda sounded weird.
The only thing that I'm trying to fix now is this little bit of what seems like HF "hash", I'll call it, when the trem is going, and I hit more than 1 note at a time. It's slight, but it's annoying. Any thoughts there?
I knew it was gonna be bass heavy, so i tried to account for that before I even built it. On fire up, cleans were beautiful. I started with a 5Y3 and had around 370V plates. I fiddled with the pre voltages and actually liked them better above 200 at the first ax7 plate. The only issue with this amp is that it sounded great from 1-9 on the dial. It just fell apart when cranked, and when I hit it hard. It just sagged and compressed way too much for my tastes, and the flub just took over when you hit it.
I tried a bunch off different things. First I put in the smallest value 1M pot I could find, around 870K. Then dropped all the couplers a bit and 1st catrhode. Of course that cured it but then the cleans suffered. I made the grid leaks 100K for the 6V6s. That actually helped the most, but I still wasn't 100% happy. I could tighten it up by increasing the NFB, but then everything got a lil boring. Finally I put a resistor from wiper to ground on the volume pot, and boom, there it was. Then I crept back up on all the other things I reduced.
Now I can crank it, sit right in front of it, and bang away. It's a good volume. I ended up settling on a 5V4, and actually like the higher voltages across the board, just for the clarity. I think things settled around 380 or so on the 6V6 plates, and 230 on the first stage.
I think if I were to put another pot on front the soul control would be a good one. For kicks I put a cut-type control across the cathodyne, in the usual spot. It didn't need it but I was curious, and though it worked, it kinda sounded weird.
The only thing that I'm trying to fix now is this little bit of what seems like HF "hash", I'll call it, when the trem is going, and I hit more than 1 note at a time. It's slight, but it's annoying. Any thoughts there?
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Re: Brown Princeton
Can't tell for sure from the pics but it looks like you have a grid stopper on the PI (attached to the socket). If you don't - this makes a HUGE improvement on "cranked" tone IMO. If I were building again I'd start at 1M and go down from there. I also preferred the first stage voltage above 200 and went back to that (pretty sure my posted schematic values are correct/current).
Cool amps fer sure!!!
Cool amps fer sure!!!
Deric®
Re: Brown Princeton
Very colorful
Some fartiness is typical of most Tweed and Brown / Blonde Fenders, especially with higher output pickups (like P90's and humbuckers). Some say it is part of their charm. I often use the lower level input if I am going to crank my 6G2 - not a fix, but it helps a little. But I don't want to change much because at lower volumes, it is so wonderful.
Some fartiness is typical of most Tweed and Brown / Blonde Fenders, especially with higher output pickups (like P90's and humbuckers). Some say it is part of their charm. I often use the lower level input if I am going to crank my 6G2 - not a fix, but it helps a little. But I don't want to change much because at lower volumes, it is so wonderful.