18Watt.com

Bieworm wrote: ↑

Mon 08/02/21 12:10 am

I have a discrepancy in the plate voltages of the PI that need some attention.

That plate voltage discrepancy doesn't matter. That's a very small margin.

After you get your B+ voltage to the sweet spot, you might want to adjust the reverb voltage, but if it sounds good, it's obviously optional.

Thanks,
Josh

Got the voltages where they should be, more or less... for now I will settle for that.
The G2 controller works, but it's not that linear as I would expect. When you turn it more down it drops, but rises back immediatly. Not to full power, but still. When you roll it down to 9 O'clock it's clearly less in volume, but overdrives more than it was set to on the gain. I think it works, but one needs to learn to use it I guess...

Combo almost ready. White piping still to do, along with the handle and rubber feet.
The guy wants tilt back legs!!! Dank, only Fender sells such things... would break my heart to add those

Assembled...

Very nice! Though I'm sure you already know my next question...

JMPGuitars wrote: ↑

Sun 08/08/21 6:10 pm

Very nice! Though I'm sure you already know my next question...

Yes I know about the obligatory sound clip

Beautiful work, my friend. If good looks were measured in dollars, it would be a million!

Jack

TriodeLuvr wrote: ↑

Sun 08/08/21 11:45 pm

Beautiful work, my friend. If good looks were measured in dollars, it would be a million!

Jack

Thanks Jack. I'm pretty satisfied too with the results

Picture backside. Reverbtank bag under construction Quick Soundclip:
https://www.dropbox.com/s/zvrs98usa5w68 ... b.m4a?dl=0

Sounds great!

When you make your reverb tank bag, live a tiny little bit of room height-wise. You probably will want to slide a piece or two of cardboard in there the length/width of the tank (covering the tank opening).

Thanks,
Josh

JMPGuitars wrote: ↑

Mon 08/09/21 7:46 am

Sounds great!

When you make your reverb tank bag, live a tiny little bit of room height-wise. You probably will want to slide a piece or two of cardboard in there the length/width of the tank (covering the tank opening).

Thanks,
Josh

I learned a lot about the behavior of tanks. I always put a long piece of adhesive foam on top of the tank to prevent resonance and 2 long pieces of that foam on the bottom of the combo to suspend the tank from the cab. The bottom is closed with aluminiumfoil covered 2mm plexi sheet, bolted to the tank.

After playing with it I feel the amp is too bass heavy, even on the bright switch setting. The speaker buzzes.. very annoying. I built the amp playing a telecaster, but now I played my jazzmaster and the buzz appeared...
I was thinking to swap the .022uf coupling cap between V1a and the gain pot with a .0047uf. Good idea to start?

Maybe. Also maybe try a different speaker first?

Bieworm wrote: ↑

Tue 08/10/21 3:34 pm

After playing with it I feel the amp is too bass heavy, even on the bright switch setting. The speaker buzzes.. very annoying. I built the amp playing a telecaster, but now I played my jazzmaster and the buzz appeared...
I was thinking to swap the .022uf coupling cap between V1a and the gain pot with a .0047uf. Good idea to start?

Is the owner still on about tilt-back legs? Decoupling the bottom of the combo from the floor when it is tilted may affect the low end, so something to consider. I would also be inclined to consider the speaker choice but also trimming the coupling cap down. Do you have a current schematic, as you built the amp?

colossal wrote: ↑

Wed 08/11/21 10:31 pm

Bieworm wrote: ↑

Tue 08/10/21 3:34 pm

After playing with it I feel the amp is too bass heavy, even on the bright switch setting. The speaker buzzes.. very annoying. I built the amp playing a telecaster, but now I played my jazzmaster and the buzz appeared...
I was thinking to swap the .022uf coupling cap between V1a and the gain pot with a .0047uf. Good idea to start?

Is the owner still on about tilt-back legs? Decoupling the bottom of the combo from the floor when it is tilted may affect the low end, so something to consider. I would also be inclined to consider the speaker choice but also trimming the coupling cap down. Do you have a current schematic, as you built the amp?

Thanks! I used the latest schematic in the Downloads area, just added reverb.
But I think the problem was something else. It was the position it stood in the room. It's a laminate floor. When I was preparing for the solution to the problem yesterday I noticed the buzz was gone. The amp stood a few meters from the spot It was before, when It buzzed. Maybe a hollow part of the floor was the cause

Did some experimenting and I like it a LOT!!
Here's what I did: initially I installed the bright-fat switch. After finding it not fat enough to be very different I swapped the 1uf additional/switch-in cathode bypass cap with a 2.2uf. That was a lot more what I wanted. Overall the amp is really bassy , even on the bright setting. I like that, but not for every situation. The switch I used for the bright-fat switching happens to be a DPDT mini toggle. I only used 1 side for the switching, so there was this spare side waiting to get involved.
Now, I put a .01uf cap in series with the .022uf coupling cap before the gain pot.. but it can be switched out when the fat switch is activated. This means that on the fat setting there is a .022uf coupling cap + the extra 2.2uf on the cathode over V1a, whilst on the bright setting there is only a .047uf cathode bypass cap and the series .022uf+ .01uf = .0068uf.
Sounds really great!!!
https://www.dropbox.com/s/smoka9iyloal4 ... 10812?dl=0
https://youtu.be/uLRlic0Alac

Sounds great! A really nice variety of tone (and the demo only scratched the surface of the dirt it should be capable of). Perhaps now you understand why I like ZP's Superlite TMB circuit so much.

JMPGuitars wrote: ↑

Thu 08/12/21 3:32 pm

Sounds great! A really nice variety of tone (and the demo only scratched the surface of the dirt it should be capable of). Perhaps now you understand why I like ZP's Superlite TMB circuit so much.

I will build myself one too!!! I want to keep it as is... great little amp!!!
And it's dirty all right!!!
Vol was on 2 for the clip , gain not even max

Great job. Sounds really nice.