I had a thought I'd like to run by those more experienced than I.
Most of the playing I do is for worship bands. Overdrive is not always welcome. I love the clean dumble sound and have been intrigued by the "small special" amp I've seen pics of (60's OD in the file section; basically an ODS with no OD).
It struck me that I could buy a silverface princeton (non-reverb) and, using the stock iron, turning it into a all-clean 6v6 dumble. Anyone ever tried this? I'd be interested to hear your thoughts.
-TR
All Clean Dble
Moderators: pompeiisneaks, Colossal
Re: All Clean Dble
Actually, I just did that to my long suffering princeton. No switching at all, just 5 knobs, V, T, M, B, P. I won't say it sounds like a dumble, but I really like it. You can build it right on the original tag board.
-Bob
-Bob
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Funkalicousgroove
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Re: All Clean Dble
I did an 80 watter without the OD, with Reverb and a PPI Master, I DID include the PAB, I got ALOT of compliments on the tone of that amp. I'd Imagine if you added the 12BH7 Cathode follower/driver stage after the PI it would be SPECTACULAR.
Funk
Funk
Owner/Solder Jockey Bludotone Amp Works
Re: All Clean Dble
A post PI driver stage? Cool. That's something I've never run into. Is there an amp with readily available schematics (as in, on schematic heaven or something similar) that employs that? Or better yet, do you have en electronic copy of the schematic you used that you'd be willing to share? That's something I'd love to explore. Thanks!Funkalicousgroove wrote:I'd Imagine if you added the 12BH7 Cathode follower/driver stage after the PI it would be SPECTACULAR.
Funk
-TR
"In this world you will find hardship and trials; but take heart, for I have conqured the world."
John 16:33
John 16:33
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Funkalicousgroove
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Re: All Clean Dble
More newbie questions:
I have the 1997 Humble Overdraft Specimen Revision 1.2 schematic. Is that a good one to use for this type of conversion? Its the more simple version without the bright switch, PAB and jazz/rock switch. Are those essential? The amp (SF Bassman donor) will be mostly used for clean/edge of overdrive tone. I assume I'll swap out the anode and cathode resistors and the bypass caps to the Dumble values, or is it the tone stack alone that makes the difference? What about the 220k resistor between the stages that is bypassed by the 330pf cap? Would bypassing the mixing resistor after the second stage produce a similar effect?
Skeezbo
I have the 1997 Humble Overdraft Specimen Revision 1.2 schematic. Is that a good one to use for this type of conversion? Its the more simple version without the bright switch, PAB and jazz/rock switch. Are those essential? The amp (SF Bassman donor) will be mostly used for clean/edge of overdrive tone. I assume I'll swap out the anode and cathode resistors and the bypass caps to the Dumble values, or is it the tone stack alone that makes the difference? What about the 220k resistor between the stages that is bypassed by the 330pf cap? Would bypassing the mixing resistor after the second stage produce a similar effect?
Skeezbo
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Funkalicousgroove
- Posts: 2235
- Joined: Mon Jul 25, 2005 8:04 pm
- Location: Denver, CO
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Re: All Clean Dble
you definitely want the PAB if you're building a 90's amp, it'll sound anemic without the boost on the OD
Owner/Solder Jockey Bludotone Amp Works
Dumble tone stack for clean sound.
I did wire up that skyline stack in the Bassman 100, but I left as many of the Fender parts in as I could: the 250p treble cap, the 250k bass pot, ect.
It does have a really great clean sound, but I can see why you would need the PAB to get some overdrive.
One interesting thing I did do, however, was to leave out the 9.8k resistor on the bass pot and wire up a 25k pot like a midrange control. The stack has two midranges now. The treble control and mid from the Dumbleish stack are kind of Voxish; the new midrange seems to trying to control the low mid, but is easily swamped if you have the bass control over 4.
I am going to use the head as a bass amp (if it is loud enough). I got the Avatar 2x12" with the Neo speakers-what a great deal. I think I'll try a 100k bass pot or boost the new mid pot to 50k to see if I can get a usable range that is in balance for both.
Anybody remember an old Oliver bass amp that had a four band stack? I used one once long ago and thought the tone controls were great, but the amp wasn't loud enough. I wonder if that stack is similar.
It does have a really great clean sound, but I can see why you would need the PAB to get some overdrive.
One interesting thing I did do, however, was to leave out the 9.8k resistor on the bass pot and wire up a 25k pot like a midrange control. The stack has two midranges now. The treble control and mid from the Dumbleish stack are kind of Voxish; the new midrange seems to trying to control the low mid, but is easily swamped if you have the bass control over 4.
I am going to use the head as a bass amp (if it is loud enough). I got the Avatar 2x12" with the Neo speakers-what a great deal. I think I'll try a 100k bass pot or boost the new mid pot to 50k to see if I can get a usable range that is in balance for both.
Anybody remember an old Oliver bass amp that had a four band stack? I used one once long ago and thought the tone controls were great, but the amp wasn't loud enough. I wonder if that stack is similar.