Blues Custom Mods
#1
Posted 12 December 2008 - 01:55 PM
#2
Posted 13 December 2008 - 03:03 AM
I haven't found it to be too bright though but I'm sure it could use some tweeks and better components.
#3
Posted 13 December 2008 - 03:32 AM
#4
Posted 14 December 2008 - 05:32 AM
#5
Posted 14 December 2008 - 06:38 AM
Keep us posted=d>
#6
Posted 15 December 2008 - 12:46 PM
You say it's too bright to you guitarists and then its probably awful to harp.

#7
Posted 15 December 2008 - 05:27 PM
#8
Posted 16 December 2008 - 05:01 PM
Quote
I was wondering about mods a while back and was looking for schematics. Couldn't find any at the time. Gibson/Epiphone actually has schematics on their site but not for all of their amps. Go figure. Are these accurate?
And does anyone know if there are different versions of this amp? Some reviews I've seen online seem to say BC30's bought more recently have a slightly different sound and come with different stock tubes. Anyone?
#9
Posted 17 December 2008 - 10:26 AM
#11
Posted 22 December 2008 - 05:21 PM
Quote

?? mod: make it more rectangular
Interesting. What is that picture from?
#12
Posted 23 December 2008 - 03:06 AM
Quote
Interesting. What is that picture from?
#13
Posted 23 December 2008 - 09:00 AM
Quote
I was wondering about mods a while back and was looking for schematics. Couldn't find any at the time. Gibson/Epiphone actually has schematics on their site but not for all of their amps. Go figure. Are these accurate?
And does anyone know if there are different versions of this amp? Some reviews I've seen online seem to say BC30's bought more recently have a slightly different sound and come with different stock tubes. Anyone?
The later ones come with Sovtek 6L6's rather than 5881's. I haven't heard one of the earlier ones but there certainly wasn't the 'ice pickiness' in the tone that people remarked on when I got mine so poss the vale change made a difference.
Dumping the Sovteks and the Chinese Rectifier for some vintage valves certainly sorted the tone out with mine. I'm on the hunt for some vintage ECC83's at a sensible price now to complete the package.
Genevieve - My Epi Les Paul Standard in Natural fitted with BB Pros
Dot Studio in faded cherry with GFS Mean 90 in neck and Gibson 57 Classic in bridge.
Home built 52 style tele with matched custom wound Bare Knuckle 'Yardbirds'
Epi BC30 fitted with NOS '61 RCA Blackplates and a '59 Mullard GZ34
Strat style bitsa affectionately known as the plank
Korean Tanglewood TW400N acoustic
EJ200CE Super Jumbo
AXL Player Bass
Very little talent & big dreams!
http://www.soundclick.com/ianwigg
#14
Posted 23 December 2008 - 05:31 PM
#15
Posted 25 December 2008 - 06:47 AM
Quote
Interesting. What is that picture from?
gibson.com
... something about opening in ginza...
http://www.gibson.co...m%2Din%2DTokyo/
#16
Posted 02 January 2009 - 07:07 AM
#17
Posted 02 January 2009 - 07:47 AM
Straight out of the Box BC30 with stock Sovtek 5881 - Line Voltage 120
Sovtek 5881 Plate 23W dissipation + Screen 3W dissipation.
B+ Voltage - 406VDC - Measured from Pin 3 to ground
Plate Voltage - 375VDC Measured from Plate to Cathode
Screen Voltage - 374 VDC Measured Pin 4 to Cathode
Cathode Voltage - 31VDC - Measured from Cathode to ground
Cathode Bias Resistor - 250 Ohm Rated 25W
Cathode Current - 62mA per tube
These specs were at idle.
I spoke with Pyotr on the phone tonight. He seemed to favor the 6L6GC for a replacement output tube, but he said that any 5881/6L6GC should be alright in this amp. While we were on the phone, Pyotr popped in a pair of EL34's and got these numbers: B+ 396v, Plate 367V,
28.5v Cathode voltage, 57mA per tube, Line Voltage 116v.
I'm going to run these numbers by Lord Valve to get his opinion....minus the 6550 recomendation that is...ce of op trans failure?or do you think it will handle it?
#18
Posted 02 January 2009 - 07:54 AM
That'll get it.
Let's do this conservatively. Remove ONE cap, then play and see if it's better (to your ears) or still needs less brightness. If it needs less, remove one more and then re-play. Etc.
First - remove C6.
Second - C5
Third - C10.
#19
Posted 02 January 2009 - 07:55 AM
1. - Hard wire pins 1 and 8 together on the output tube sockets, or better yet, hard wire pins 1 straight to ground.
2. - Change R45, & 46 to 1k/5W.
3. - Change R42, & 43 to 5.6k/1/2 W
With these mods, you can go back and forth between EL34 and 6L6 by just swapping the tubes.
#20
Posted 02 January 2009 - 07:57 AM