Small 6V6 Combo w/Reverb

[jon]

+1 for Princeton Reverb


....but....



....buying a Blues Junior and gutting it seems like an expensive way to build a different amp. I'd recommend looking for something cheaper to gut. Something that doesn't work perhaps. Or even buy an empty cabinet and have a chassis made for it. I've seen brand new Blues Jr. size cabinets on eBay for $150, and a chassis could be made for under $50. I doubt you can buy a BJ for $200, so this approach should save you some bucks.

Careful slibert you would want to suggest something illegal here.

[Colossal]

Jon, I don't follow you. What about Steve's post implies something illegal? He is talking about taking a junk Blues Jr., gutting it, repurposing the cabinet and chassis. His point was, and I completely agree, that you will spend almost as much money on something that is not a good solution as you would just getting exactly what you want and need for the project at hand.

[sliberty]

Jon, I don't follow you. What about Steve's post implies something illegal? He is talking about taking a junk Blues Jr., gutting it, repurposing the cabinet and chassis. His point was, and I completely agree, that you will spend almost as much money on something that is not a good solution as you would just getting exactly what you want and need for the project at hand.

Forgive Jon, for he is a goofball. He was assigning a different meaning to the phrase "BJ for $200".

[Reeltarded]

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[Colossal]

Wow, that went right up and over my head! Nice one!

[dcribbs1412]

Not sure what your budget/experience is...
An organized kit might start you in the right direction.
You might take a look at the Weber kits
6A14(Princeton) or 6A20(DR)...also David Allen(Allen Amps) has
very nice kits and parts for a PR or DR build
I played an original 65 Princeton then built the Allen SweetSpot...
I really like the Sweetspot.

Darin

Darin,

Can you comment on the sonic differences (if any) that you experienced with the Real 65 Princeton versus the SweetSpot??? I have seen the differences between the PR and the Sweetspot on the schematic (thank you Mr. Fowler!) and I am interested to see how these changes sound. One, the cathodyne PI in the SweetSpot is fixed bias (the Paul C mod) and the reverb driver is wired with parallel grids but a common cathode and anode. There are also a few other little component changes here and there as I recall.

Anyway, I have a huge interest for Princetons right now as I have a clone on the bench and it is fantastic sounding. The reverb and vibe are just amazing.

Thanks in advance.

Colossal,
unfortunately I did not have the chance to play both side by side.
Things being what they were(speakers,tubes and over a year ago), I'm not sure if I can make a decent comparison
but what I remember most is having to crank the 65 to get a
tone that felt really good...using the vol knob to clean up,it was very nice
The reverb was nice but seemed to add more top end to the tone...if that makes any sense. I was playing a strat. Also the 65 had a 10"
On the other hand the SS(12" RWB) with the raw control seemed get the goods at lower volumes. The reverb seems more mellow.Trem is outstanding. FWIW I do remeber the 65 had newer tubes (JJ's i think) and my SS has NOS blackplate power and pre's with a Mullard GZ34.
btw THE GUY WAS ASKING 2200.00 FOR THE 65...out of my(wife's) price range.This pretty much ended my quest for(high dollar) vintage gear.I think I have around 700.00 in my SS. I think Mr. Allen has taken the PR to another level with the changes in the SS I recommend it.Not sure if this answers any ?'s

Darin

[TwoString]

I've modded some amps in the past (nothing intrusive, some basic tone stack mods, transformer swaps, etc). I just finished building the Matchless DC-30 kit from Ceriatone...other than missing the rectifier wiring by 1 pin, I didn't make any huge mistakes with the build. I've built tons of effects pedals, but I know that doesn't really compare. I modded my Blues Jr, and I love the size of that amp and what I can get out of it, but like any tweaker, I gotta build more!

A slightly modded Princeton with 6L6s could be the right way to go. I still plan to remove the trem controls though, since I'd like to keep the controls clean and try to stuff it into a smaller tweed style combo. I'll work on a schematic of what I think will work and I'll post it here.

The Allen kits look nice, but I'm hoping to not have to spend that much money.

[Colossal]

Thanks Darin, that was very helpful. I was just curious but your comments solidify my own comparative analysis between the two (at least on paper). I have a PR clone right now and it has a 6L6 power section with a slightly modified cathodyne (for a little more drive to the 6L6s), and small changes in the reverb and trem. This amp is actually a little dark but sounds very, very good with the stock Eminence Legend speaker. I hooked it up to an outboard oversized 1x12 cab with a ported/partially open back (about 20% open area) with an EV, it is the Voice of God. The EV adds some clean headroom, is louder by about 10-20% (guess), huge presence and 3D qualities.

So it seems that other designers are trying to take the PR and just make certain small improvements to address these underlying issues for modern players.

p.s. I have a Mullard GZ34 that I tried in the clone and that made the single biggest difference in the tone. It went from good/decent sounding with a JJ GZ34 to absolutely stunning with the Mullard.

[Colossal]

A slightly modded Princeton with 6L6s could be the right way to go. I still plan to remove the trem controls though, since I'd like to keep the controls clean and try to stuff it into a smaller tweed style combo. I'll work on a schematic of what I think will work and I'll post it here.

The Allen kits look nice, but I'm hoping to not have to spend that much money.

TwoString,

You won't be disappointed with that choice! However, you will not be able to run a pair of 6L6s with BJr. iron. If you are serious about your tone, don't skimp on your transformers; you will spend 1/2 to 2/3 of what you would have with quality steel and you will be disappointed with the outcome when you hear one with good transformers. The clone on my bench right now is a production amp and it has what I believe is a Heyboer PT by the looks of it. It is running much too hot for my comfort level but the voltages all check out and the amp sounds really good.

I think if you look carefully, you will be able to find a reasonably priced Tweed cab, maybe get a speaker that you like used (a speaker is a very large part of the tonal equation), get a chassis made by DDawg Amps (Brian is a very nice fellow) or from RJ (also a helluva guy and a resident here). Source some good quality transformers direct from Heyboer or another manufacturer.

You can get by with new production tubes and still have a great sounding amp, but going cheap on transformers even with high quality NOS tubes will not give you an amp that will sound as good as one with good steel. Sorry to harp on this but if money is an issue, I think in the long run you will be much happier doing it right than doing it now for a marginal return. You can get all of your components (and good ones too) from Mouser Electronics or any of the guys here that offer components such as RJGuitars.

Not trying to railroad you into my philosophy, so please don't take this as such!

[TwoString]

No worries...I'd never go cheap on transformers, but I think I can save money overall by sourcing my own parts rather than buying a kit (or at least I'll feel better about it in the end).

Again, this is where the dumb newb starts to come out, but what would I need to do to convert the build over to 6L6? I know I'll need a different power transformer, but any component value changes to look out for?

If there is an existing source for this info, or at least somewhere to learn about power sections and swapping tube types, I'll happily read up on whatever you can provide.

[Firestorm]

p.s. I have a Mullard GZ34 that I tried in the clone and that made the single biggest difference in the tone. It went from good/decent sounding with a JJ GZ34 to absolutely stunning with the Mullard.

This is SO true in many amps. It breaks my heart because the Mullards are getting rarer.

[Colossal]

No worries...I'd never go cheap on transformers, but I think I can save money overall by sourcing my own parts rather than buying a kit (or at least I'll feel better about it in the end).

Cool. Yes, sourcing your own goodies is not only fun and part of the finished boutique/hand-made vibe, but also a good way to get exactly what you want and control costs.

Again, this is where the dumb newb starts to come out, but what would I need to do to convert the build over to 6L6? I know I'll need a different power transformer, but any component value changes to look out for?

If you look at the Princeton Reverb schematic, find the cathodyne PI. Increase both the plate and cathode load resistors from 56k to 100k. You may want to google the Paul C Mod as this converts the cathodyne to fixed bias from cathode bias as a means to keep the low end from collapsing. This is the nature of the cathodyne but the sound contributes to the overall Princeton tone.

I hope Firestorm and BillyZ can comment on the differences between the Princeton and Deluxe Reverbs on this point.

If there is an existing source for this info, or at least somewhere to learn about power sections and swapping tube types, I'll happily read up on whatever you can provide.

If you want to go hardcore (but definitive/comprehensive with worked examples) check out Richard Keuhnel's book on power amp design (http://www.ampbooks.com/home/books/power-amps/). My copy is well loved and falling apart but it is a great resource and I still read it often. There is a section on the cathodyne (aka concertina or split load PI), long tailed pair, and paraphrase inverters and worked examples based on classic amps.

[Colossal]

p.s. I have a Mullard GZ34 that I tried in the clone and that made the single biggest difference in the tone. It went from good/decent sounding with a JJ GZ34 to absolutely stunning with the Mullard.

This is SO true in many amps. It breaks my heart because the Mullards are getting rarer.

Truly! I acquired a small stash of Mullard GZ34s and I am glad I did. I am also on the prowl for more but they really bite into your capital when they come up. I was blown away by the result though.

[Firestorm]

p.s. I have a Mullard GZ34 that I tried in the clone and that made the single biggest difference in the tone. It went from good/decent sounding with a JJ GZ34 to absolutely stunning with the Mullard.

This is SO true in many amps. It breaks my heart because the Mullards are getting rarer.

Truly! I acquired a small stash of Mullard GZ34s and I am glad I did. I am also on the prowl for more but they really bite into your capital when they come up. I was blown away by the result though.

If you ever see a Telefunken-branded GZ34, grab it! Mullard-made in Blackburn, but supposedly selected for Telefunken. A/B'd a batch of other Mullards to this one and it beat them all.

[Colossal]

If you ever see a Telefunken-branded GZ34, grab it! Mullard-made in Blackburn, but supposedly selected for Telefunken. A/B'd a batch of other Mullards to this one and it beat them all.

Nice! Thanks for the tip!

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