200Watt AB763

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

200Watt AB763

Post by jon »

Just saying. how would you go about building a 200W AB763 Fender. The main goal is to keep the basic tonality the same.

Would you use 8 6L6's, 4 KT88/6550's?
Firestorm
Posts: 3033
Joined: Fri Jan 25, 2008 7:34 pm
Location: Connecticut

Re: 200Watt AB763

Post by Firestorm »

I suppose it depends on how much tone coloration you want from the output tubes. KT88s and 6550s seem subjectively cleaner than 6L6s (to me).
AcornHouse
Posts: 53
Joined: Fri Mar 21, 2014 1:21 pm
Location: Bidwell, OH
Contact:

Re: 200Watt AB763

Post by AcornHouse »

Why not a Super Twin? Yes, I realize that its only 180w, but might be a good starting point.
http://el34world.com/charts/Schematics/ ... _schem.pdf
Zippy
Posts: 2052
Joined: Tue Apr 25, 2006 11:18 pm

Re: 200Watt AB763

Post by Zippy »

Have you considered running a slave amp - PI and output of a Twin? Maybe just run another Twin in parallel from the line out?
potatofarmer
Posts: 50
Joined: Fri Dec 02, 2011 2:54 am

Re: 200Watt AB763

Post by potatofarmer »

Having a slave power amp seems like the winner to me. 200W through a pair of pairs of speakers is going to be noticeably louder than 200W through just one pair. I'm not sure I'd put 200W of power tubes in a combo. Not without mounting an air conditioner on the back, at least...

When I saw Swans last year they had three silverface Twins... just for the pedal steel. Gira was playing through I think a bass amp, and there was also a rhythm guitarist playing through a JCM800 and a Musicman. Plus a bassist and a pair of drummers. They ran through the house PA as well for the most punishingly loud show I've ever heard. Made Sunn O))) look like Yanni.

That triplet of Twins though, you could definitely hear the pedal steel at all times.
User avatar
NickC
Posts: 1814
Joined: Fri May 14, 2010 1:05 pm
Location: Upstate New York

Re: 200Watt AB763

Post by NickC »

potatofarmer wrote:Having a slave power amp seems like the winner to me. 200W through a pair of pairs of speakers is going to be noticeably louder than 200W through just one pair. I'm not sure I'd put 200W of power tubes in a combo. Not without mounting an air conditioner on the back, at least...

When I saw Swans last year they had three silverface Twins... just for the pedal steel. Gira was playing through I think a bass amp, and there was also a rhythm guitarist playing through a JCM800 and a Musicman. Plus a bassist and a pair of drummers. They ran through the house PA as well for the most punishingly loud show I've ever heard. Made Sunn O))) look like Yanni.

That triplet of Twins though, you could definitely hear the pedal steel at all times.
Exactly!

Add a second amp/speaker set (of comparable power) and get a 3dB increase in SPL. Add a third amp/speaker set and get another 3 dB (total of 6dB increase between the two) increase in SPL. Also get improved dispersion with the three-combo-amp rig and more manageable stage volume (considering the point-source issues of a single extremely high power single amp-rig).

To achieve a 6dB increase in SPL from one amp alone, you'd have to quadruple its' output watts. Gets expensive and cumbersome to get that much power from a tube amp.


http://en.wikipedia.org/wiki/Decibel
User avatar
jon
Posts: 566
Joined: Fri Feb 24, 2006 6:45 pm
Location: North East

Re: 200Watt AB763

Post by jon »

This is for a prospective customer.

Would you run annode or cathode follower input to power tubes
User avatar
Phil_S
Posts: 6048
Joined: Tue Oct 23, 2007 10:12 pm
Location: Baltimore, MD

Re: 200Watt AB763

Post by Phil_S »

Gonna need some hefty trannies and a hefty chassis to go with it! And a roadie to carry it! Is this for guitar? For bass, I could understand.
User avatar
gui_tarzan
Posts: 607
Joined: Thu Jan 16, 2014 3:10 am
Location: The 26th State

Re: 200Watt AB763

Post by gui_tarzan »

Set him (or her) up with a Crown PA amp and a pair of EAW stacks if they want to be that loud.
--Jim

"He's like a new set of strings, he just needs to be stretched a bit."
Stevem
Posts: 5144
Joined: Fri Jan 24, 2014 3:01 pm
Location: 1/3rd the way out one of the arms of the Milkyway.

Re: 200Watt AB763

Post by Stevem »

Jon, are you after having 2.5 times the clean head room of a 85 watt regular twin, or twice the volume.
If your answer is that latter you either need twice the amount of speakers, or 10 times that wattage of a standard twin reverb, that's how the human ear and the math works.
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!

Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
User avatar
roberto
Posts: 1841
Joined: Tue Nov 27, 2007 4:45 pm
Location: Italy

Re: 200Watt AB763

Post by roberto »

I've built a 100W amp for a guy who plays "something metal".
One year later he asked me how to be even louder.

I've integrated a line out from the OT taps of the amp, that feeds an external very small amp with an alembic preamp feeding a 200W class d amp with a small toroidal for the preamp section and a smtp power supply for the power amp. The system can be muted by a footswitch and has his own eq. Sounds very natural (because the feel is taken from the first amp to be reamped), and weights less than 1kg.
User avatar
cbass
Posts: 4401
Joined: Sat Jul 23, 2011 6:17 pm
Location: Between Pomona & Bakersfield

Re: 200Watt AB763

Post by cbass »

2 twins .you are gonna have more speakers anyway.may as well just be 2 combo amps.If he needs more volume than that add 2 4x12's
Is he wanting a head? A 200 watt combo would be insane
A line out to is probably the smartest approach
User avatar
roberto
Posts: 1841
Joined: Tue Nov 27, 2007 4:45 pm
Location: Italy

Re: 200Watt AB763

Post by roberto »

You are right cbass, I forgot to tell that i've suggested him to change his two 4x12"s to something with more efficient speakers than G12T75s.

I've heard him live just one time.
Never heard anything THAT loud onstage.
User avatar
cbass
Posts: 4401
Joined: Sat Jul 23, 2011 6:17 pm
Location: Between Pomona & Bakersfield

Re: 200Watt AB763

Post by cbass »

Yes of course more effeciemt speakers is the easiest way to get louder
User avatar
Leo_Gnardo
Posts: 2585
Joined: Thu Sep 27, 2012 1:33 pm
Location: Dogpatch-on-Hudson

Re: 200Watt AB763

Post by Leo_Gnardo »

Start with your copy of a Twin or similar, right up to the output tube driver. Follow this with a line transformer. Then drive all the power amps & all the speakers you want. Bring back the Wall of Sound just like this 'un here:
You do not have the required permissions to view the files attached to this post.
down technical blind alleys . . .
Post Reply