New Project Suggestions

[purpletele]

I had this little gem of a chassis and cabinet stashed away for a pandemic.

I had purchased a Princeton Reverb No Trem board, but I am leaning more towards the AB763 Circuit.  I would like to have it powerful, standard EQ, reverb, no trem.

I will look for a speaker, but this might be a Celestion Gold 10" or Tone Tubby 10", I know I have to design around the worst case speaker size.

I would like to have this amp be able to be used on stage, I had good success with including a Line Out for a similar Princeton that I built.

I am thinking of using the same transformers that I have for the Deluxe Reverbish amps that I have, they included a forty watt  OT.

I don't have the room for a Cap Reservoir Board so I would need to consider Cap Cans.

I am imagining that I would have to take the Hoffman Deluxe Reverb Board and recreate that without the Tremolo.

Any suggestion for existing schematics and layout for something as described.  The last photo is of the Princeton Reverb that I put into the same chassis 2 years ago.

[shooter]

leaning more towards the AB763 Circuit.

haven't you had enough of 763!

go bold, try something from VOX, want a challenge try Bogner, or even bolder;
take piece from....., add it to a piece from......., make it work with a PA from...... 

dream big

[sluckey]

Man on fire! My hero.   

Look at my TDR... http://sluckeyamps.com/tdr/tdr.htm

Should satisfy your specs. May give you some ideas. The board is skinny, only 2.2" wide and 10.8" long. It would lay in that chassis and still have plenty of room between the board and pots to lay in axial filter caps like Hoffman uses.

[purpletele]

leaning more towards the AB763 Circuit.

haven't you had enough of 763!It seems kind of redundant, but they are just incredible amps and my buddies love them.

go bold, try something from VOX, want a challenge try Bogner, or even bolder;
take piece from....., add it to a piece from......., make it work with a PA from...... 

dream big

I will be looking into the Vox projects, I'm not into punishing myself with the AC15.

[shooter]

It seems kind of redundant, but they are just incredible amps and my buddies love them.

My son started playing them (twins) when he was 14, by 30 I told him I'm sick of looking at these things.  He fell on hard times, bounced back into a re-issue Marshall, now he wonders why he was so pig headed 
I told him don't even call when the PCB gets wonky!

[purpletele]

Man on fire! My hero.   

Look at my TDR... http://sluckeyamps.com/tdr/tdr.htm

Should satisfy your specs. May give you some ideas. The board is skinny, only 2.2" wide and 10.8" long. It would lay in that chassis and still have plenty of room between the board and pots to lay in axial filter caps like Hoffman uses.

Thanks, this fits the requirement very well.  It also makes sense for me to stay inside of the ropes and work with a proven design.
I have a few for chassis' stacked up so there is time for Vox type amp in the future, I think for this cool cabinet it should be the Go To circuit.

I am trying to think of how a tweed configuration would sound in that circuit with 6l6's and that is intriguing.

1. The picture that I have attached shows the Plan View of the chassis with an 11" by 2.5 inch piece of paper indicating the board.  It looks possible to get the Cap Board inside the chassis, but I think it would be better to place the Cap Board on the bottom of the board with a light weight shield, great idea. 

I don't think I would be comfortable with the caps lined up along the edges of the chassis. 

2. I have a center set speaker so the transformers can go to each end and leave clearance for the speaker.  I think the cap board will be well placed underneath.  That will give me plenty of room up top to have a neat and accessible board.

3. Do you think the same 40 Watt xfmr set will be too much for this cabinet?  I think it will be fine with a really nice speaker.  I've learned to buy a back up set of xfmr's just to make it through start up. 

4. What does the RAW control do to the tone?  I am not familiar with that control on an amp.

5. Would the Mid Control add anything to the value of the tone?

This seems like a logical circuit for this project, I need to dust off Visio and Illustrator for the face plates.

Thank you for the present, this will be fun!




 

[sluckey]

I may have spoken too soon. What are the dimensions of your chassis?

[purpletele]

I may have spoken too soon. What are the dimensions of your chassis?

I have 14" x 5" that is workable in the chassis.

I think it will work fine if it designed correctly. 

[tubenit]

What about trying a Dumblish style tone stack & lower the value of the cathode caps on the 1st 3 gain stages AND keep everything else a Tweed Deluxe ala Sluckey?  It has 3 relay footswitches but you could get by with just the mid-boost and the PAB  (preamp boost). 

This schematic is VERY close to one of my 3 amps.  And I like it very much. 

With respect, Tubenit

[purpletele]

What about trying a Dumblish style tone stack & lower the value of the cathode caps on the 1st 3 gain stages AND keep everything else a Tweed Deluxe ala Sluckey?  It has 3 relay footswitches but you could get by with just the mid-boost and the PAB  (preamp boost). 

This schematic is VERY close to one of my 3 amps.  And I like it very much. 

With respect, Tubenit

Jeff,

Thank you, I am intrigued.  I don't know much about the Dumble style, but I am curious, and I know that it's a cool take on the Fender circuit.

BV

 

[tubenit]

Something like this. These are the values I use and like. I like the D topology ( midboost & pre-amp boost) but prefer different values.

Actual Dumble values are in contrast shown.

IF you're wanting something a little different this time, it may be worth considering?

With respect, Tubenit

[Ed_Chambley]

I am currently drawing a schematic you may be interested in.  I have built 7 clones of the 1963 Vibroverb to date.  People love the rounder sound, but I plan in advance to slow the tremolo.


Tone stack is tough if you are not old and been collecting 350/70K tap pots, but Weber has them and Doug did.  Most measure 250K and 50K or close at the tap, but if you ask CJ to measure you some and send some with higher tolerances, he will.  It makes only a little difference since the pot is easy to add resistors to, but why if you can get the correct ones.


I got 12 Allen Bradley from Steve at APEX years ago.  I mention this incase you prefer a better, more accurate larger pot.


This time I changing things some.  Single Channel, relay switching for V1 to shave bass for the overdrive section which is an EF86 overdrive.  Reverb circuit needs a dwell.  The relay will send the signal through the overdrive after reverb insertion and through the FX loop which is based around a 12AT7, which I find I prefer.  Still working out details, but I have breadboarded and it is close.  I still plan the stock tremolo because the amp sounds great stock and I want to keep that.  I also have some 10" CTS speakers from 1962 in great shape.


With all the cool pedals available, the loop and overdrive provides options no available amp I have seen does.  Of course, I will design it to kill the loop separately, but personally I am an always on loop guy.  I like modulation and even square wave tremolo.  Just more options.


Differences, Cathode Bias using Tung-Sol 5881.  The true Output Transformers are referred to as 40 watts, but the correct one begins saturation at a much lower volume than a Deluxe Reverb.  It has no bell covers like a Super Reverb or Bassman.  NO MASTER, just a volume for the overdrive and send/return for the loop.  I am planning voltage control for the output tubes simply because I have never been able to figure out what is being regulated as in VVR or Variable Voltage Regulator.


Maybe someone will read this and explain it to my ignorant ass maybe.


I will be using a 2, 10 cab which makes the correct chassis hard to find.  I make them.


Or you can build a Gibson 77.

[shooter]

Or you can build a Gibson 77.

He won't listen, he's got Fenderbraindisorder 

I think a nice dark-side SE by pete, or a GA-5TON with 6L6's (not sure the periwinkle could handle KT88's :)

[sluckey]

I am planning voltage control for the output tubes simply because I have never been able to figure out what is being regulated as in VVR or Variable Voltage Regulator.

Maybe someone will read this and explain it to my ignorant ass maybe.

VVR is a misnomer. All it does is adjust the voltage. Nothing is being regulated. If line voltage changes, the VVR output changes. If the load changes, the VVR output changes. A better name would NOT include the word "Regulator". 

[bmccowan]

Or you can build a Gibson 77.

Great idea! Although that chassis might be a bit small.  I've rebuilt and built many Gibsons, GA-5s, 20s, 25s, 30s, and 40s, but never a GA-77. Hmm, maybe I should build one. I have a chassis and some iron that'll work. And given current circumstances, I have the time. Oh Lord, one more on the list.

[Willabe]

Wow Ed, big project.

Or you can build a Gibson 77.

I built a Gibby GA-77, great amp. 

Just fix/change the TS to a AB763.

[purpletele]

leaning more towards the AB763 Circuit.

haven't you had enough of 763!

go bold, try something from VOX, want a challenge try Bogner, or even bolder;
take piece from....., add it to a piece from......., make it work with a PA from...... 

dream big

After playing the Deluxe and Princeton for the past few weeks I do think I'm am stuck in a box, I need overdrive.

I think 40 Watts is too much for the Champ cabinet after blasting my Deluxe.  I like the idea of a Dumble OD section that Tubenit suggested.

I'm not in a hurry, I would like this amp to be very well thought out.

BV

[purpletele]

Or you can build a Gibson 77.

He won't listen, he's got Fenderbraindisorder 

I think a nice dark-side SE by pete, or a GA-5TON with 6L6's (not sure the periwinkle could handle KT88's :)

I'm open to anything, you guys are not out of bounds, I have enough Fender tone and Marshall tone

I tend to get obsessed and take my eye off the ball (work), so I was thinking about something in my comfort zone.

I can handle something different.  I am not sure what a Dark-Side SE by Pete looks like.  Nor do I know about the GA-5TON sounds like.

It's a cool cabinet, and I love the thought of a setting that little gem down with friends and then just ripping and blowing folks away with tone. 

I'll build whatever circuit best suits the cabinet. The design room is limited and the speaker becomes a design constraint.  I thought about designing around a Celestion Gold then that eliminates ambiguities with clearance.

BV

[shooter]

just ribbing, there is something about "doing what you know - well".  A plumber looks lost with a fluke, same for a EE and hammer 

you're "one the right track", you "know now" that you want OD, figure out how to inject that into "your proven pick".  small steps save face-planting on the sidewalk.

I get the sense you're a real player, a real player can plug into ANY amp and make it sound good! 

[bmccowan]

I built a Gibby GA-77, great amp

Willabe, Like most/all Gibson's it looks like there are several versions. Did you build the one with the 12ay7 preamp and 12au7 PI?

[Willabe]

..... Did you build the one with the 12ay7 preamp and 12au7 PI?

Yes.

And a 12AX7 CF.

Here's the link to me build;

http://el34world.com/Forum/index.php?topic=14835.msg141885#msg141885

[bmccowan]

Thanks Willabe, That's a good build thread - and you really do a great job right through to the finish. I tend to get itchy to start the next project and often end up with multiple finished chassis hanging around until I feel like firing up the table saw.
Your thread did inspire me to finish repairing an old GA-30 I started a few years ago. New caps, replaced about 1/2 of the resistors. Its a rare version with 1 6SJ7, 2 6SQ7, 2 6V6, 5Y3 - 1-12" and 1-8" speaker. I think its the earliest GA-30 as it maintains a lot of the GA-25 circuit. Likely a 1948, it has two service stickers from 1952. Cool sound and a cool look.

[Willabe]

There's also a 4 knob Gibby, GA-70 Country and Western.

It doesn't have the extra single knob tone control. Same as a Fender tweed Princeton 5F2a single tone control.

If you don't think you need it or have room on the chassis face, you could just leave it out. 
   

[bmccowan]

I've kept my eye out for one of those C&Ws. I now have repaired/refurbished many Gibsons. I need to get some of them into the hands of people who will play them. I feel kind of guilty (and crazy) for having a Gibson amp museum at home. I'm interested in donating some amps to young players who cannot afford to buy. Trying to find a good organization to do that through.

[Willabe]

I feel kind of guilty (and crazy) for having a Gibson amp museum at home.

You wouldn't have a Gibby GA-83S would you? How about a GA-55V?   

I'm interested in donating some amps to young players who cannot afford to buy.

Well, that leaves me out. Oh to be young again. 

[bmccowan]

You wouldn't have a Gibby GA-83S would you? How about a GA-55V?

No, but they'd be cool to see and hear in person. Pretty rare and the 83 is pretty bizarre. I have focused on the smaller amps - BR - 4, 6, and 9. GA 5 (several versions) GA 8, 8T, 9, 18, 20 (multiple versions), 30, and the wonderful GA-40. I have a few epi versions.
A nice benefit to repairing old Gibsons is that if your wiring is messy, it's historically correct!

[Willabe]

A nice benefit to repairing old Gibsons is that if your wiring is messy, it's historically correct!