Suggest a build for me

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Suggest a build for me

Post by Noval_novice »

I have a Carvin Bell Air amp that recently died. Output tube arced and burnt the hell out of one of the PCB's. Boring story. Anyway, I'd relike to reuse the cabinet (a 2x12 loaded with Carvin's version of vintage 30's) and the chassis if possible. I plan on removing the fake vinyl tweed and recovering in tolex, but was uncertain of what to build in the chassis. There are a total of 9 9-pin sockets on the chassis. See the blurry picture below:

Any suggestions are welcome. Oh, and I am not terribly experienced having only made a 5f1, 5e3 and ax84 HO within the last year, so simple is better!
User avatar
jhaas
Posts: 139
Joined: Thu Aug 02, 2007 12:35 pm
Location: Vermont, USA
Contact:

Re: Suggest a build for me

Post by jhaas »

Is that a 4xEL84 amp?

You might consider the Trainwreck Rocket. That requires seven 9-pin sockets, and one octal for the rectifier. Not terribly complex.

Adding a little complexity to it, you could add reverb which would take up another 9-pin socket, but you'd also need a reverb tranny, pan, rca jacks, etc.

Lots of folks around these parts are very high on the reverb rocket.
User avatar
sliberty
Posts: 1324
Joined: Fri May 26, 2006 5:03 pm

Re: Suggest a build for me

Post by sliberty »

If you like chimey cleans and really smooth overdrive, the Rocket would be my recommendation as well. Lovely sounding amps.

Another choice would be the DC30. Maybe not as clean as a Rocket, but not what I would all aggressive overall.

If you want more grit, consider a Liverpool. Same tube compliment. Pretty aggressive.
User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Re: Suggest a build for me

Post by Noval_novice »

There is a reverb pan in the cabinet, but I wasn't sure I should attempt a build with reverb since I am a noob.
Alexo
Posts: 477
Joined: Thu Mar 22, 2007 3:27 am
Location: The Hudson Valley

Re: Suggest a build for me

Post by Alexo »

Iirc, the Bel Air runs those EL84's hot Hot HOT! Like 400 - 450 volts hot. Crazy. Possibly related to your tube failure?

If I was going to rebuild that amp with those transformers, I'd bore out the holes for octal sockets and run a quad of JJ 6V6's, or maybe just a pair of 6L6's or something.

S'pose you could keep the EL84's if you dropped in a sag resistor and/or a couple Zener diodes and got the plate voltage down by 100 volts or so (which is a lot to drop).
Last edited by Alexo on Wed Sep 29, 2010 5:22 pm, edited 3 times in total.
Life is a tale told by an idiot -- full of sound and fury, signifying nothing.

...in other words: rock and roll!
User avatar
jhaas
Posts: 139
Joined: Thu Aug 02, 2007 12:35 pm
Location: Vermont, USA
Contact:

Re: Suggest a build for me

Post by jhaas »

BTW, I don't see the link to the picture you mentioned in your original post.

The Rocket Reverb is *very* well documented here, and you'll get boatloads of support from the forum, should you need it. You've got three under your belt, I think you'll be fine with it.
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Suggest a build for me

Post by M Fowler »

I also suggest the rocket reverb and it is no harder for a newbie to build then a regular Rocket or Vox AC 30. With the extra available noval socket you could go with a two tube reverb which would sound better.

There are many posted layouts and schematics for the one tube reverb Rocket by Normster, Rawnster and others including myself.

Mark
User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Re: Suggest a build for me

Post by Noval_novice »

Yeah, sorry. I guess my blurry pic was still too big to upload. I'd be willing to get new transformers and save the old ones for something else in the future. I have to admit I was somewhat pleased when it started to smoke, because the clean channel was the only one worth using.
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Suggest a build for me

Post by M Fowler »

So your able to use whatever transformers you want now and can go with octal power tubes as well for a Marshall EL34 amp or Fender brighter toned amp 6L6.
User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Re: Suggest a build for me

Post by Noval_novice »

Ok, I am getting interested in the Rocket with Reverb. At the least, I would like to utilize the reverb tank I now have in the amp. It is an Accutronics 9GB2C1B. I believe it is a large tank with medium decay and a 10k input impedence, 2575 Ohm output impedence. How would I need to modify your reverb circuit to accomodate this tank?
User avatar
FYL
Posts: 654
Joined: Fri Feb 17, 2006 1:05 am

Re: Suggest a build for me

Post by FYL »

It is an Accutronics 9GB2C1B. I believe it is a large tank with medium decay and a 10k input impedence, 2575 Ohm output impedence.
Yep. A custom 6 springs unit that IMO should only be used with a proper dwell control. Well, unless you're into surf music.
User avatar
Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: Suggest a build for me

Post by Structo »

Too bad you fried the Carvin.

There are some simple mods you can do to the Soak channel that greatly improves it.

I own a Belair as well but I haven't done the mods either.
The amp does have excellent clean tone and it is a very loud amp.

Now that I hear the plates are at 450v that may explain it. Although I never went through power tubes on it.
In fact I ordered a set of JJ's for the amp and never installed them.....
Tom

Don't let that smoke out!
User avatar
M Fowler
Posts: 14036
Joined: Wed Jan 16, 2008 2:19 am
Location: Walcott ND

Re: Suggest a build for me

Post by M Fowler »

The layouts I am referring to are on page three of this link.

https://tubeamparchive.com/viewtopic.ph ... sc&start=0
User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Re: Suggest a build for me

Post by Noval_novice »

Update on this thread:

Although the Rocket Reverb sounded nice, I finally decided to build an 18 watt. Channel 1 is EF86 input and Channel 2 is the standard tremolo. I also incorporated a simple PPIMV and a cut control. The tremolo is LED biased, which is pretty cool, IMO. I tried to make use of some of Merlin's discussion of the design of a small signal pentode gain stage, so I used different values for biasing than the typical AC30, etc.

Initial impressions are good. It is a very nice clear and semi-distorted tone from either channel, but the EF86 input is really lovely. Now all my 12AX7 input amps sound dull.

I wound up using a different chassis and iron. Really the only things I did use from the initial combo were the speakers (Carvin's version of the Vintage 30), the cabinet (which I retolexed) and some of the knobs. Drilling my own chassis and making a layout were new tasks for me as was the retolexing. Definitely a learning experience. Here are a few bad photos. Any constructive criticism is very welcome.
You do not have the required permissions to view the files attached to this post.
User avatar
Noval_novice
Posts: 124
Joined: Mon Jun 14, 2010 11:22 pm
Location: Tennessee

Re: Suggest a build for me

Post by Noval_novice »

Gutshots:
You do not have the required permissions to view the files attached to this post.
Post Reply