Bandmaster Ultra Phonix Amp

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Charlie Wilson
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Re: Bandmaster Ultra Phonix Amp

Post by Charlie Wilson »

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
mojotom
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Re: Bandmaster Ultra Phonix Amp

Post by mojotom »

A250k for bass too, at least that's what I prefer.

Those preamps tend to be bass heavy plus the PI entrance didn't cut any compare to a Fender type AT7 inverter.
Aaron
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Re: Bandmaster Ultra Phonix Amp

Post by Aaron »

The plate on 3b connects to the opto bug and the .1 then goes to earth.

Aaron
10thTx
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Re: Bandmaster Ultra Phonix Amp

Post by 10thTx »

schematic corrected and reposted below
Last edited by 10thTx on Wed Jul 19, 2017 10:34 am, edited 1 time in total.
Aaron
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Re: Bandmaster Ultra Phonix Amp

Post by Aaron »

10thTx wrote: Wed Jul 19, 2017 1:40 am Corrections noted. Any others?
.047 coupling cap on the normal channel.

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norburybrook
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Re: Bandmaster Ultra Phonix Amp

Post by norburybrook »

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
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.

Bluesmaster values: Cathodes-4.7uF 2k2/4.7 1k8 and the plates 150-120k on V1 for example. Just curious :D


Marcus
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sonicmojo
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Re: Bandmaster Ultra Phonix Amp

Post by sonicmojo »

Mark wrote: Tue Jun 06, 2017 4:24 am I wonder if the output transformer is the stock one or a Bassman O/P transformer?
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.

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.
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Bryan
10thTx
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Re: Bandmaster Ultra Phonix Amp

Post by 10thTx »

Corrected schematic.

Any other corrections? Is there some consensus on the 47k slope resistors vs the 33k & 100k?

With respect, 10thtx
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dcribbs1412
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Re: Bandmaster Ultra Phonix Amp

Post by dcribbs1412 »

I agree with Charlie
Looks like a yellow band on both slopes
Is there a clip of this amp or has anyone heard/played it?

D
Charlie Wilson
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Re: Bandmaster Ultra Phonix Amp

Post by Charlie Wilson »

norburybrook wrote: Wed Jul 19, 2017 8:36 am
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
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.

Bluesmaster values: Cathodes-4.7uF 2k2/4.7 1k8 and the plates 150-120k on V1 for example. Just curious :D


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.
CW
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ToneMerc
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Re: Bandmaster Ultra Phonix Amp

Post by ToneMerc »

Charlie Wilson wrote: Wed Jul 19, 2017 9:26 pm
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.
CW
[/quote]

CW, it's never hurts to one's own biggest hype man. It's all about perception of value; it's not about what you actually have, it's about what you think you received. That label helps offset lighter wallet indegestion syndrome.

TM
mojotom
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Re: Bandmaster Ultra Phonix Amp

Post by mojotom »

sonicmojo wrote: Wed Jul 19, 2017 9:18 am
Mark wrote: Tue Jun 06, 2017 4:24 am I wonder if the output transformer is the stock one or a Bassman O/P transformer?
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.

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.

Not much but I noticed on the Sebago website regarding theirs UP modded amps that they would change the OT to a bassman OT for better bass. I thought by deduction it was part of the mod for those amps.
I have seen some Deluxe/Showman/dual showman/Twin UP amps (not inside) and didn't noticed a bigger OT than stock (maybe just an upgrade for smaller OT amps, Vibrolux/Vibroverb/Bandmaster).
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mhartman
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Re: Bandmaster Ultra Phonix Amp

Post by mhartman »

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.
Charlie Wilson
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Re: Bandmaster Ultra Phonix Amp

Post by Charlie Wilson »

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.
Could you elaborate a little on the preamp tweeks and have you seen these done to any Blackface Fenders with reverb?
CW
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mhartman
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Re: Bandmaster Ultra Phonix Amp

Post by mhartman »

Charlie Wilson wrote: Thu Jul 20, 2017 12:24 am
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.
Could you elaborate a little on the preamp tweeks and have you seen these done to any Blackface Fenders with reverb?
CW
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).
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