![Confused :?](./images/smilies/icon_confused.gif)
CW
Moderators: pompeiisneaks, Colossal
Charlie, having just built another bluesmaster, why do you say this is one? I can see quite a few variations in resistor and cap values from the BM I built compared to this.Charlie Wilson wrote: ↑Tue Jul 18, 2017 4:24 pm Hello, those yellow bands on the slope resistors are 4, so 47k slopes. Probably larger than 1k5 for power tube grids. So this is not a modded Bandmaster, its a Bluesmaster(clean) built into a Bandmaster chassis. So much for being a " one of a kind prototype".![]()
CW
I also understood that the UP had a Bassman OT. I happened to stumble on a bargain '65 Bandmaster that had a later Bassman 022871 OT. A couple of years ago I modified it with the sparse UP information garnered at that time. Some of this new example's information definitely matches but I'll have to revisit...I also thought that the cathodes on V1/V2 were not shared but they are in this one.
Hello Marcus, Yeah your right those are not exactly Bluesmaster values but they are close enough that I would call it more of a tweeked Bluesmaster than a modded Bandmaster. What I'm really responding to though, is the little note Dumble put on the amp saying no one can look inside the amp because it is a one of a kind prototype.norburybrook wrote: ↑Wed Jul 19, 2017 8:36 amCharlie, having just built another bluesmaster, why do you say this is one? I can see quite a few variations in resistor and cap values from the BM I built compared to this.Charlie Wilson wrote: ↑Tue Jul 18, 2017 4:24 pm Hello, those yellow bands on the slope resistors are 4, so 47k slopes. Probably larger than 1k5 for power tube grids. So this is not a modded Bandmaster, its a Bluesmaster(clean) built into a Bandmaster chassis. So much for being a " one of a kind prototype".![]()
CW
Bluesmaster values: Cathodes-4.7uF 2k2/4.7 1k8 and the plates 150-120k on V1 for example. Just curious![]()
Marcus
Hello Marcus, Yeah your right those are not exactly Bluesmaster values but they are close enough that I would call it more of a tweeked Bluesmaster than a modded Bandmaster. What I'm really responding to though, is the little note Dumble put on the amp saying no one can look inside the amp because it is a one of a kind prototype.
sonicmojo wrote: ↑Wed Jul 19, 2017 9:18 amI also understood that the UP had a Bassman OT. I happened to stumble on a bargain '65 Bandmaster that had a later Bassman 022871 OT. A couple of years ago I modified it with the sparse UP information garnered at that time. Some of this new example's information definitely matches but I'll have to revisit...I also thought that the cathodes on V1/V2 were not shared but they are in this one.
With the Bassman OT, I think my UP-ish Bandmaster sounds a lot bigger than my stock '65 Bandmaster (also have one), but it probably did before my UP mods anyway. Does anyone know if a Bassman OT was part of the general UP formula? It might be worth noting on the schematic.....The rear picture on Reverb sure looks like the profile of a Bassman OT versus a stock Bandmaster OT.
Could you elaborate a little on the preamp tweeks and have you seen these done to any Blackface Fenders with reverb?mhartman wrote: ↑Wed Jul 19, 2017 11:43 pm Bandmasters and Pro Reverbs came stock with very undersized OTs. Dumble changed the Bamdmaster transformers on every UP that I've seen. Also, based on the 4-5 that I've seen, the Bluesmaster setup seems to be the standard for UPs. That being said, I've seen a variety of tweaks to the individual preamp sections.
I haven't seen any actual Dumbles with reverb (other than the HH photos that we've all seen). I've seen inside Brandon's "Bludophonix", which has reverb, but I have no idea if that one was based on a real Dumble with reverb or if he just added reverb to a UP style circuit. The preamps variations range from clean to crunch to all out gain. One of the interesting cleans looked much to me like a take on a vox tonestack. Every UP that I've seen has had the Marshall style phase inverter setup. I'm not a huge fan of the Bandmaster/Showman UP setup, except for the clean side, because I'm mostly a bedroom player and you need to get loud to enjoy them (much like a trainwreck).Charlie Wilson wrote: ↑Thu Jul 20, 2017 12:24 amCould you elaborate a little on the preamp tweeks and have you seen these done to any Blackface Fenders with reverb?mhartman wrote: ↑Wed Jul 19, 2017 11:43 pm Bandmasters and Pro Reverbs came stock with very undersized OTs. Dumble changed the Bamdmaster transformers on every UP that I've seen. Also, based on the 4-5 that I've seen, the Bluesmaster setup seems to be the standard for UPs. That being said, I've seen a variety of tweaks to the individual preamp sections.
CW