6G15 Reverb

General discussion area for tube amps.

Moderators: pompeiisneaks, Colossal

User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

6G15 Reverb

Post by jon »

Just finished building one of these. Sounds really good but I end up having to run the dwell and mix quite low otherwise is is to over the top. Any thoughts?
Cliff Schecht
Posts: 2629
Joined: Wed Dec 30, 2009 7:32 am
Location: Austin
Contact:

Re: 6G15 Reverb

Post by Cliff Schecht »

Get a different tank? Or easier than that is to try to remove a spring, but then you'll lose some of the lushness of the typical Fender reverb.
Cliff Schecht - Circuit P.I.
tubeswell
Posts: 2337
Joined: Thu Mar 27, 2008 6:42 am
Location: Wellington. NZ

Re: 6G15 Reverb

Post by tubeswell »

Maybe you have the pan mounted the wrong way? Some pans are horizontal mount, others are vertical mount. Check the pan code is correct for the way you have it mounted.
He who dies with the most tubes... wins
Kazooman
Posts: 71
Joined: Sat Jan 02, 2010 10:04 pm

Re: 6G15 Reverb

Post by Kazooman »

Did you use a 12AT7 at the input stage?

I own an original copy and built a clone. They do not sound the same, even if I switch tanks and / or tubes. Both are nice, but I prefer the original.

[IMG:639:426]http://i55.tinypic.com/16c9x8m.jpg[/img]
User avatar
Phil_S
Posts: 6048
Joined: Tue Oct 23, 2007 10:12 pm
Location: Baltimore, MD

Re: 6G15 Reverb

Post by Phil_S »

Tanks are or are not what they used to be. I'm not trying to be witty, either. The point is, the original Gibbs tanks are no longer available. There is quite a bit of reading material if you search for "reverb tank review" and it may be instructive to see what people are saying.

Gibbs became Accutronics, which was purchased by Belton, a Korean company AFAIK. A "new" player, MOD has appeared in the marketplace and the reading I've done suggests that MOD may yet eat Accutronics lunch. I don't really know, though. (Aside, I have no idea who makes MOD, and I wouldn't be surprised if they come from the same factory. Call me a cynic.)

Here are some random samples for reading:
http://www.tdpri.com/forum/archive/inde ... 76899.html
http://www.amazon.com/MOD-Reverb-Tanks- ... ewpoints=1
http://www.300guitars.com/2009/12/mod-reverb-tanks/
Kazooman
Posts: 71
Joined: Sat Jan 02, 2010 10:04 pm

Re: 6G15 Reverb

Post by Kazooman »

Thanks for the information and links to the MOD tanks. They look really nice.

As I indicated, I have tried swapping tanks in my two reverbs without a whole lot of success. The difference in sound between my vintage unit and the clone seems to be in the rest of the components, not the tank. Having said that, I would still be interested to try a MOD tank to see how it sounds in BOTH reverbs.

I guess the only way to really make a valid comparison is to use the clone on and off for forty years to see how the components age :)

BTW: I did do a filter cap job on the original and updated to a three prong plug without altering the mojo.
Kazooman
Posts: 71
Joined: Sat Jan 02, 2010 10:04 pm

Re: 6G15 Reverb

Post by Kazooman »

I mentioned forty years of ageing. Actually, the original Reverb is a 1965, so it is 47 years old. It goes well with my 51 year old Bandmaster.

I wish I could say that I bought these recently using the profits from some iphone app I wrote in my dorm room as a college freshman, but that is not the case. Both were bought used, but within a few years of their birth. I am 11 years older than my Bandmaster :cry: No gigs for a long-long time, but still loving bringing the vintage gear back to life and building clones and pedals, just for fun.
User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

Re: 6G15 Reverb

Post by jon »

The problem I am having is that anything above 1/4 on the dwell and mix and I am in sponge bob land.
Kazooman
Posts: 71
Joined: Sat Jan 02, 2010 10:04 pm

Re: 6G15 Reverb

Post by Kazooman »

I will think about that and try to do some comparison experiments.

As I mentioned before do you have a 12AT7 in the first stage? A 12AX7 would have too much gain.
User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

Re: 6G15 Reverb

Post by jon »

12at7 in first
6k6gt driver
12ax7 recovery
User avatar
jjman
Posts: 753
Joined: Sat Oct 06, 2007 2:33 pm
Location: Central NJ USA

Re: 6G15 Reverb

Post by jjman »

With it switched off via the pedal, is the unit providing a boost to the clean signal? Cut? If it's not reducing the dry signal I'd reduce the wet side's gain in the 1st stage on the 12at7. Go with a lower resistor than 10k between the plate resistor and the PS. Maybe 8 or 5k.
If it says "Vintage" on it, -it isn't.
Paul Fawcett
Posts: 24
Joined: Fri Aug 20, 2010 2:37 pm
Location: Richmond, VA, USA

Re: 6G15 Reverb

Post by Paul Fawcett »

jon wrote:The problem I am having is that anything above 1/4 on the dwell and mix and I am in sponge bob land.

Try various sizes of resistor from the wiper to the dry side of the mix control. For my 6G15-inspired build (there were some differences), about 100K was just about right.
Mark
Posts: 3271
Joined: Sat Jan 15, 2005 8:10 am
Location: Sydney Australia

Re: 6G15 Reverb

Post by Mark »

Hi Jon

I have been wanting to build one of these for a while. When I first got into the amp building thing, I bought a Torres stand alone reverb kit. This was a huge mistake, the parts and chassis were rubbish.

I did experiment with this circuit, I found it was very easy to get the reverb unit to distort and if I tried things like split loads on the plate of the amplification stages the reverb sounded flat and lifeless.

Then there is the matter of mounting the spring, the originals weren't simply bolt to the cab, there were screws and springs used in an effort to isolate the spring from spurious noises. There was also a locking mechanism too.

Perhaps Kazooman can show us detailed shots of his original unit?

Keep me in the loop Jon.
Yours Sincerely

Mark Abbott
User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

Re: 6G15 Reverb

Post by jon »

I'm already exploring this. and I will keep you in the loop.
Kazooman
Posts: 71
Joined: Sat Jan 02, 2010 10:04 pm

Re: 6G15 Reverb

Post by Kazooman »

Mark wrote:Hi Jon


Then there is the matter of mounting the spring, the originals weren't simply bolt to the cab, there were screws and springs used in an effort to isolate the spring from spurious noises. There was also a locking mechanism too.

Perhaps Kazooman can show us detailed shots of his original unit?
Glad to help. I will take some pictures today and will post them soon.

You are correct that the pan is mounted with springs at the four corners to isolate it from vibration. There is a metal arm that can be used to clamp the pan down firmly for transporting the unit.

When I built my clone I ended up with a pan that needed to be mounted face down and this created some space problems in the enclosure. I had to change the location of some of the components on the chassis. I did mount the pan with springs.
Post Reply