It is currently Mon Mar 16, 2020 2:20 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 86 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Go to page Previous  1, 2, 3, 4, 5, 6  Next
Author Message
Post subject: Re: 1966 DeLuxe Reverb
Posted: Sat Mar 08, 2014 4:59 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Oct 21, 2010 12:42 am
Posts: 61
Location: Illinois
Jealous!!!


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 2:43 am
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
/

Looking at the plate voltage of 382VDC .. :cry:

Isn't this a bit low?!


Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 8:22 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Yeah. 382VDC seems 40VDC too low. Yoo have another GZ34/5AR4 rectifier you can try out? Is this voltage after or before re-capping the main PSU?


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 2:11 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
:wink:

I should have an old Sovtek GZ34 around, will try.


The new caps are in, still 382 VDC.


Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 2:29 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Or you can try a strong 5U4GB. If the voltage goes up with this rectifier, the old GZ34/5AR4 is tired. New 5AR4 run a good 15-20VDC above new 5U4GB's.

Wait! One sec. What is that 470k-ohm resistor for (yellow-purple-yellow)? The DR does not need a balancing resistor between the first two PSU caps. Those caps are in parallel = total capacitance of 32mfd, in the first filter stage. Not in series, like the first two caps in most 6L6GC amps. Series caps need balancing resistance.

My bet is if you lift one leg of that resistor the B+ voltage will go up. That resistor maybe partially shorting the second cap, of the first stage, to ground.

http://www.webphix.com/schematic%20heav ... _schem.pdf

http://www.webphix.com/schematic%20heav ... _schem.pdf


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 3:14 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
:?:

BMW2002Ti,

What difference (performance wise) will higher VDC make, if it goes up to, say 425V?

Maybe more headroom, or something else ..?!?

:?:


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Mon Mar 10, 2014 3:23 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
For Class AB1, push-pull, it puts the tube on a curve plot with better response character. Like setting up a car engine, so that it responds best to the particular chassis.


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Sat Mar 15, 2014 11:54 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
.


New F&T cap in the bias supply :shock:


Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Wed Mar 26, 2014 5:27 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
:shock:

Death cap gone .. :lol:


Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Wed Mar 26, 2014 5:47 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Did you get the plate voltage up into the 425VDC range?

Thanks!


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Wed Mar 26, 2014 5:58 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
BMW2002Ti wrote:
Did you get the plate voltage up into the 425VDC range?

Thanks!



Not as yet.
The tech told me the PT has been rewound at some stage, so that may be the issue with the voltage.

I hope this bad guy will sort it out :mrgreen: :mrgreen: :mrgreen:

Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Thu Mar 27, 2014 1:24 am
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 14, 2013 4:41 pm
Posts: 764
Location: Sydney. Australia
Beemer,
would you know how old this rectifier tube is?

Looks like it's original to the amp, but I'm not 100% sure ....~? :?:

Image
Image
Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Thu Mar 27, 2014 1:51 am
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Dunno. The dimension of the bottle look Philips/Mullard, but the plates don't quite look British. You have any small etched date-manufacturer codes near the bottom of the glass. Where the envelope meets the base?


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Thu Mar 27, 2014 8:23 am
Offline
Professional Musician
Professional Musician
User avatar

Joined: Sat May 22, 2010 10:53 pm
Posts: 1467
Location: deep down in Florida...
The rectifier looks like the same one that came in my 67 Vibrolux Reverb...

Image

I believe this is the code Beemer is talking about

Image


Top
Profile
Post subject: Re: 1966 DeLuxe Reverb
Posted: Thu Mar 27, 2014 6:45 pm
Offline
Rock Star
Rock Star
User avatar

Joined: Sat Jul 03, 2010 2:18 pm
Posts: 6544
Correct.

f32 = GZ34

B6 (_) 1 = 1966, B = February, 1 = week. (Dunno what the missing digit is, so this line was partly guessed).


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 86 posts ]  Go to page Previous  1, 2, 3, 4, 5, 6  Next
Go to page Previous  1, 2, 3, 4, 5, 6  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: