So I got this about 4 years ago (was one of the lucky ones to get a kit shipped before things went south at Brown Note) and then we had to relocate from Ohio to Atlanta Ga area. I finally got my workspace set back up and I'm stoked to get this sucker built.
Here's some pics of the progress so far.
Special shout out to the Amp Garage community. I was able to build my first amp about 6 years ago with the help of this community, a D clone from an old Fender Bassman 10, and I've had the bug ever since
Mark
You do not have the required permissions to view the files attached to this post.
Last edited by Blindog on Mon Sep 23, 2013 4:42 am, edited 4 times in total.
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
The iron is Heyboer, the PT has a Brown Note sticker with the part number so I'm sure Moss had them made.
Yeah, I'm really pleased with the chassis and the components...'cept they sent me 5m1 grids stoppers instead of 5k1, so I went through my stash of resistors and found some nos 1W 4k7 carbon comps, and measured until I found 4 close to 5k1
Mark
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
Well, fired her up with the trusty light bulb limiter, no problems...applied full power, and I couldn't get one pair of 6L6's to bias..the pot had no effect. Powered down and did some checking, and the 24K resistor from the bias pot to ground was wide open...go figure! Popped a new one in and all is well there now.
Everything seems to be working OK, except for 2 things that have me scratching my head:
1. The OD Drive control doesn't do anything when adjusted...maybe a hint of change when turned all the way up...
2. The reverb is working, but I get a 60hz hum in the background when turn up the control.
Anyone have some thoughts? This is my first HRM build, as well as a build with reverb. I've attached a copy of the layout from Brown Note.
Mark
You do not have the required permissions to view the files attached to this post.
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
The reverb tank has a transducer in it that is susceptible to stray electromagnets fields (much like a guitar pickup). The end of the tank that connects back into the amp's return input needs to be kept away from the power transformer as well as the power cord.
JazzGuitarGimp wrote:The reverb tank has a transducer in it that is susceptible to stray electromagnets fields (much like a guitar pickup). The end of the tank that connects back into the amp's return input needs to be kept away from the power transformer as well as the power cord.
Gotcha...I'll do a 180 on the tank when I put it back in the cab. I bet it'll take care of that hum...now to track down the OD drive control issue..
Many thanks!
Mark
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
For the OD control, check the ground on the pot as well as the pot itself. If the ground is not solid you'll get a very slight change as you turn the pot. You should be able to almost silence the amp with the OD at 0.
FYI, its a good idea the check every component as you build, measure the resistors and caps, check the pots sweep and switches function.
Bob-I wrote:For the OD control, check the ground on the pot as well as the pot itself. If the ground is not solid you'll get a very slight change as you turn the pot. You should be able to almost silence the amp with the OD at 0.
FYI, its a good idea the check every component as you build, measure the resistors and caps, check the pots sweep and switches function.
Hey Bob, good to hear from you! I checked the drive pot (in circuit) and it measures out ok...also reflowed the connections, no dice
I haven't modified the dropping string, it's per the layout. On a positive note, I was able to eliminate the reverb hum with a different tank orientation.
Stumped!
Mark
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
So I was staring at the schematic of the Bluesmaster in the files section trying to solve my drive pot issue, and I kept thinking it had something to do with the HRM. Sure enough, I had the input to the HRM stack connected to the 220k plate instead of the 150K (these are the values on the layout). The layout shows an arrow pointing to the 220k side for the connection to the slope resistor on the HRM board...flipped the connection and all is well!
So now I can start tweaking I'm still wondering about my preamp voltages though...I'm hoping someone that built this circuit can chime in..
Thanks for everyone's input.
Mark
"- Yeah, can we have everything louder than everything else? Right!"- Ian Gillan
766]http://i5.photobucket.com/albums/y167/leleduke/Blue%20monkey%2088/100_4258.jpg[/img]
766]http://i5.photobucket.com/albums/y167/leleduke/Blue%20monkey%2088/100_4233.jpg[/img]
766]http://i5.photobucket.com/albums/y167/leleduke/002-1.jpg[/img]
