Deluxe reverb crammed into Princeton reverb chassis.

Paul G.

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I'm old and tired. My gigging amp is an Allen Accomplice Jr. While it it pretty light at 38 lbs., but the cab is pretty bulky. I was thinking of putting a single-channel AB763 into a PR chassis and cab running Deluxe Reverb transformers. (I've owned PRs, I need a bit more power and a better phase inverter). Anybody done this? Any stumbling blocks? Was going to stick to the cap can to save space, unless having the preamp common to power amp ground causes a problem.

I'd need to punch one more 9-pin hole, and open up the PT hole, otherwise, it should be good, right?
 

JohnnyCrash

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I built a (single channel) 40 watt Super Reverb in a Princeton Reverb chassis and cab. I run it with an Eminence Legend 1058.


F96BD9E1-8E35-470A-8914-1AD916F6741F.jpeg
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schmee

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I've done it. Cap can is fine. Still.... keep the preamp section grounds all near the input jacks.
I have some messy notes. But I think there are better layouts out there for it. Rob Rob has it I'm pretty sure.

-The Normal channel 220k going to the PI .001 cap can be removed , leave the little disc cap to the PI and one 220k resistor. However, I can't remember if that cap value was changed in the end or not. If too bright, go to a .01 cap or in between.
In fact some say the 220k resistor is no longer needed there at all.
My understanding is you will have just slightly less gain than the two channel DR has by eliminating one of those 220k resistors. I did not hear much difference.

However, I must caution, how much weight and size will you lose? Not much. Transformers and speaker drive the weight. A few inches of pine cab/baffle loses only ounces, maybe a pound? A few jacks and pots dont weigh much at all.
 

King Fan

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I don't know much about AB763s, but our encyclopedic friend Rob does. On his cool Blackvibe page, he says, "The Blackvibe can be built as any of the AB763 blackface amps, not just the Vibroverb. Take a look at the AB763 blackface model differences page to see what components to change to create your desired AB763 amp." And *that* cool page, as you already know, might be worth a look...
 

telemnemonics

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The dumbest thing Leo did was not put more power in the Princeton.
Who in hell needs that extra channel really? The BFDR is an underpowered oversized WTF.
My old SF Princeton has 2x6L6 but no reverb and not the BF tone.
And yeah I had a Boogie with way too much stuffed in that little box.
My problem with all the semi boutique PR size 40 watters is the dumbass mid scooped BF circuit that needs makeup in the form of reverb to sound good.
Verb fits the PR chassis fine so have at it!

Oh yeah and Im still mad at Leo for discontinuing the superior Tweed mid forward amps in favor of twang just before Rock took the arenas.
The years I fought mid scooped cheap plentiful convenience amps could have been so much more productive if Leo kept making a 5f6a and 5f8a in heads.
Grumble grumble grumble.
 

telemnemonics

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I've done it. Cap can is fine. Still.... keep the preamp section grounds all near the input jacks.
I have some messy notes. But I think there are better layouts out there for it. Rob Rob has it I'm pretty sure.

-The Normal channel 220k going to the PI .001 cap can be removed , leave the little disc cap to the PI and one 220k resistor. However, I can't remember if that cap value was changed in the end or not. If too bright, go to a .01 cap or in between.
In fact some say the 220k resistor is no longer needed there at all.
My understanding is you will have just slightly less gain than the two channel DR has by eliminating one of those 220k resistors. I did not hear much difference.

However, I must caution, how much weight and size will you lose? Not much. Transformers and speaker drive the weight. A few inches of pine cab/baffle loses only ounces, maybe a pound? A few jacks and pots dont weigh much at all.
True the weight loss will be marginal but with my back problems the longer reach and cumbersone handling is a real killer, leaning further to put the longer box in and out of a car etc, that extra leverage having to reach further for the handle is like adfing weight in the form of mechanical (dis)advantage.
 

schmee

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The dumbest thing Leo did was not put more power in the Princeton.
Who in hell needs that extra channel really? The BFDR is an underpowered oversized WTF.
My old SF Princeton has 2x6L6 but no reverb and not the BF tone.
And yeah I had a Boogie with way too much stuffed in that little box.
My problem with all the semi boutique PR size 40 watters is the dumbass mid scooped BF circuit that needs makeup in the form of reverb to sound good.
Verb fits the PR chassis fine so have at it!

Oh yeah and Im still mad at Leo for discontinuing the superior Tweed mid forward amps in favor of twang just before Rock took the arenas.
The years I fought mid scooped cheap plentiful convenience amps could have been so much more productive if Leo kept making a 5f6a and 5f8a in heads.
Grumble grumble grumble.
Having built several Hi Power Princeton Reverb types, Yes, if you use the Princeton circuit, it's a different (but great!) tone. Not as clean as the normal BF tone heard in the Deluxe and larger amps. My contention it is the different phase invertor and possibly some effect of the bias tremelo on the tone. For lower volume applications I love the Princeton circuit. For more... you need that long tailed PI. JMHO

I really dont buy into the "mid scoop" thing as much as many people. I guess I just dont like enhanced mids. If anything, there are many times gigging where I want my BF Deluxe to have a bit less mids. Like the amp I show in post #5, it has a mid control, but I really never enhance the mids above the BF circuitry when I have it! I think most of us get mids from the various OD/clean boosts we use now days, which are normally very middy devices.
 

schmee

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I don't know much about AB763s, but our encyclopedic friend Rob does. On his cool Blackvibe page, he says, "The Blackvibe can be built as any of the AB763 blackface amps, not just the Vibroverb. Take a look at the AB763 blackface model differences page to see what components to change to create your desired AB763 amp." And *that* cool page, as you already know, might be worth a look...
Yep, the Deluxe on up are basically the same amp with power mods and tweaks for speaker arrangements.
 

telemnemonics

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Having built several Hi Power Princeton Reverb types, Yes, if you use the Princeton circuit, it's a different (but great!) tone. Not as clean as the normal BF tone heard in the Deluxe and larger amps. My contention it is the different phase invertor and possibly some effect of the bias tremelo on the tone. For lower volume applications I love the Princeton circuit. For more... you need that long tailed PI. JMHO

I really dont buy into the "mid scoop" thing as much as many people. I guess I just dont like enhanced mids. If anything, there are many times gigging where I want my BF Deluxe to have a bit less mids. Like the amp I show in post #5, it has a mid control, but I really never enhance the mids above the BF circuitry when I have it! I think most of us get mids from the various OD/clean boosts we use now days, which are normally very middy devices.
Well right, we have target tones we want to hear when we hit the strings in the various ways and locations we hit them.
Some BF amps deliver almost enough or just enough mids for me but I fought that circuit for a decade before realizing it was not my target tone maker.

As for mids from pedals, I want fat mids when squeaky clean and just loathe most mid boosting pedals as well as it seems getting my mids from transistors.
Believe me I tried and tried!
The Princeton Reverb does a cool thing with the plain strings but I cannot find much use for how poorly it amplifies the wound strings.
I crave a piano like bass and cannot get it really from any BF circuit that also has fatter high strings: notably from bridge pickups because I never use fatter more middy toned neck pickups.

So our needs and methods for getting them are just different.
I sure wish I loved more of what those amps do since I owned 20-30 or the damn things!

Edit: I also seem to prefer the clean sound of amps designed fir dirt over the clean sounds from amps Leo tried to prevent distortion in, and it seems he gave the Princeton less attention in that area, which is now recognized as a good thing.
Remembering that Leo did not play, and relied on Country players to tell him if his new amps sounded good or not, while his engineers mind idealized reducing distortion as a defect to be eliminated.
 
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schmee

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"I crave a piano like bass and cannot get it really from any BF circuit... "
Ever listened to SRV? :lol:
 

Paul G.

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...However, I must caution, how much weight and size will you lose? Not much. Transformers and speaker drive the weight. A few inches of pine cab/baffle loses only ounces, maybe a pound? A few jacks and pots dont weigh much at all.
I don't have so much of a problem with weight as I do with size. I figure I'll only lose 2, maybe 3 pounds, but the 3 or so inches width and height would make a difference when I'm trying to lug my stuff into the joint in one trip, holding doors with my foot.
 

Paul G.

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...And Ive owned four BFSRs too, the best of BF...
I recently had a BFSR in my house for repairs. I had honestly forgotten how great they sound once working properly. On the other hand, it was physically too much for me to handle -- I pulled the chassis and took it up to my workroom, leaving the cab in my entry hall because I didn't want to deal with a flight of steps.
 

zook

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A Princeton circuit can be easily modified into a LTP phase inverter. Use a 12DW7 to drive and recover the reverb, and then use the now extra triode for the LTP..
 

Wally

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"I crave a piano like bass and cannot get it really from any BF circuit... "
Ever listened to SRV? :lol:
What we heard from SRV during his time from just before Texas Flood on was not what I would call typical of the BF Fenders that he used. Those amps had been massaged by Cesar Diaz to have a much tighter low end. Also, what we hear in that first album is not a Fender amp but a big Dumble owned by Jackson Browne.
I heard SRV and Double Trouble in a small club here in Lubbock before Cesar Diaz made acquaintance with SRV and made the changes to equipment that gave SRV the sound we know. When I heard them, I was not overly impressed by Stevie’s tone. I left the club with this thought STRONGLY in my mine…”those three guys are tight!! They can play!”
Ceasr Diaz introduced himself to SRV some short time later in a club in the Baltimore/Washington D.C. are, and at imho that was the final step that helped to catapult them to the big time. Browne and .Bowie’s heard them at Montrose, Switzerland. Browne recorded ‘Texas Flood’…and the world got to hear that talent.
 

schmee

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What we heard from SRV during his time from just before Texas Flood on was not what I would call typical of the BF Fenders that he used. Those amps had been massaged by Cesar Diaz to have a much tighter low end. Also, what we hear in that first album is not a Fender amp but a big Dumble owned by Jackson Browne.
I heard SRV and Double Trouble in a small club here in Lubbock before Cesar Diaz made acquaintance with SRV and made the changes to equipment that gave SRV the sound we know. When I heard them, I was not overly impressed by Stevie’s tone. I left the club with this thought STRONGLY in my mine…”those three guys are tight!! They can play!”
Ceasr Diaz introduced himself to SRV some short time later in a club in the Baltimore/Washington D.C. are, and at imho that was the final step that helped to catapult them to the big time. Browne and .Bowie’s heard them at Montrose, Switzerland. Browne recorded ‘Texas Flood’…and the world got to hear that talent.
No doubt, Stevie used a ton of amps, many all at once so you couldn't tell which one you were hearing! But the point is a BF Super, Twin or VV will get those big clean-ish grand piano like low notes all day long.... untouched.
 

Wally

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No doubt, Stevie used a ton of amps, many all at once so you couldn't tell which one you were hearing! But the point is a BF Super, Twin or VV will get those big clean-ish grand piano like low notes all day long.... untouched.
That Vibroverb has a small OT. At some volume it yields those sounds….any AB763 amp will. The difference is at what point does the amp lose that clean articulate nature. The SR does it later than any other 2x6L6 Fender guitar amp does..except for the 4x10 Concert…which is in essence a Super Reverb without the Reverb. The Bandmaster, Pro, Pro Reverb, Tremolux, Bandmaster Reverb, Vibrolux Reverb, and the VibroVerb all have a small OTs and compress at some earlier point. SRV’s Vibroverbs were no longer stock. They had big OTs and acted more like a SR due to that.
 

Paul G.

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Well, here comes the dry run. I have a client with a 74 Pro Reverb in a beat up cabinet and he's tired of lugging the thing. I have been commissioned to stuff it into a Deluxe Reverb 1x12 cab (and chassis) to cut the weight and allow him to use an amp case he already owns so the amp can be moved with the band equipment instead of dragging it around himself.

I may have to relocate the pull-boost master volume if there's not enough room for the bias board, I need to open up the PT opening, I've got a 4-ohm WGS speaker coming, and I'm using mini-toggles for bright switches. Otherwise my calculations tell me it will work. Wish me luck!
 




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