Metropoulos Forum

I was looking over the chassis layout on wiki and compared it to pictures on the Metro CD. There are a few inconsistencies on the BBri.

The CD shows a picture of the cap on the tremolo socket. Clearly it is connected to pins 2 and 8. The wiki layout shows pins 3 and 8. The cap value is different as well. The kit came with a .047uf, the wiki shows a .022uf.

The CD shows a jumper wire across pins 2 and 6. The wiki layout shows the jumper wire between pins 1 and 7.

FWIW the wiki layout resembles how the BBri was wired from the factory, minus the cap of course. Please let me know which set up to go by.

Ah! Good eye, and my apologies.

The yellow wire should go to the grid on the trem tube Pin 2 (NOT pin 3). And the cap value on the tube socket is indeed .047uf.

I'll notify Nitroliq to make these changes.

George

VelvetGeorge wrote:Ah! Good eye, and my apologies.

The yellow wire should go to the grid on the trem tube Pin 2 (NOT pin 3). And the cap value on the tube socket is indeed .047uf.

I'll notify Nitroliq to make these changes.

George

Just to clarify, the cap goes to pins 2 and 8, with a jumper wire between pins 2 and 6. Eliminate the existing jumper wire between pins 1 and 7. In other words, go by the CD not the wiki?

Thanks
Jerry

Mars, how is your BBri project coming along?

SoK66 wrote:Mars, how is your BBri project coming along?

I've populated the board. To be honest I'm waiting til they get a solid layout before I go much further. They're pretty close to having one done.







The tremolo and bias pots I'll install when I wire it in the chassis.



Here's the cabinet it's all going in, 35th Ann edition, 1 of 250.



Looking forward to hear what the Premium Sozo's sound like.

Gonna want to change the circled bit in pic here to more like that below.

SDM wrote:Gonna want to change the circled bit in pic here to more like that below.

Thank you, I will do as such. Do you have editing rights on the wiki? It will need to be updated. I just double checked it, to make sure I didn't read it wrong, when I soldered that bit. Glad I posted the pic without the pots, or you may not have caught it. Thanks again!

I think Nitroliq/Pete is finishing the new layout off, but you can see the layout link I posted in the JTM45 section thread here: Link. That layout should be correct. I do have Wiki editing privileges, but am afraid to kill the thing as I don't know what I'm doing with in there .

Hopefully Pete or George will update those Wiki board drawings and layouts soon.

Weird. I drew all the connections based on the BB board photos on the Metro CD and that's how it looks to be wired there. I can change it so the buss wire doesn't go to the central lug if that's how it's supposed to be. Unfortunately, I haven't gotten a chance to update the layout, yet as I've been swamped with other work and am leaving for vacation in a few days. I'm going to try to get to it tomorrow. For now I'd say look at the edited layout SDM provided and Fredrik's thread as mine will just incorporate the changes they made.

http://forum.metroamp.com/viewtopic.php?f=15&t=22825" onclick="window.open(this.href);return false; (same thread that SDM linked to).

Thx,
Pete

NitroLiq wrote:Weird. I drew all the connections based on the BB board photos on the Metro CD and that's how it looks to be wired there.....

Yeah just looked up those Metro CD pics on the Amp Archives site, in one pic you clearly see the trim pot turrets for the trem wired as you originally had it drawn. I think this may just be an erroneous pic that snuck through though. If you look at this pic here: LINK
You can just see that ground wire dive and curve away now from that middle trim pot turret, so I think George (or whoever did that reference board in the pics) corrected the error at some point, just forgot to correct or omit that other wrong pic.

Hmmmm...in that picture it dives away but curves back up to the middle turret, too. Take a look at the enlarged version.

I did look at the enlarged version, it's a visual trick there. The bit that looks like it shoots straight up to middle lug is the metal on the back of the pot. Take a look at the bias pot to the left in same pic to see it.

Also according to the schem and the circuit I know the corrections I made there are right. The trem wouldn't work if that middle trim pot lug was grounded as the oscillating feed to the fet is there too. If that feed is grounded no trem will happen.

Ok, not a problem. I'll correct it when I get to the layout.

Don't know how to edit Wiki yet, nor want to step on Pete's toes here, but I added BBRI layouts to my site, link in my sig. George, If you want to add any of these to the Wiki, as always feel free to do so.

Steve, thanks and no worries. The last few days have been absolutely nuts due to a rush project a client needed finished before I left for vacation.