AB763 Super Reverb and Deluxe Reverb build.

[utervo]

Hello everyone, what a great forum you have here!

I will be building a Super Reverb and Deluxe Reverb at the same time. I have schematics, layout drawings and pictures which I can use to redraw and make perhaps a 90% correct layout.

I am wondering if anyone here has made drawings with 100% accuracy for either Super Reverb or Deluxe Reverb? I am planning to then flip the self-made chassis into a head and have the reverb tank in the head also.

Thanks a lot, any tips on making a Super Reverb and Deluxe Reverb are welcome, looks like a pretty complicated build.

[Dave]

How do you get your chassis to make themselves? That's a cool trick I wish I knew how to do.

Dave

BTW......

[stratele52]

Utervo , Nice projects,

What about Fender original layout ? Not good for you ?   

http://www.thevintagesound.com/ffg/

[kagliostro]

Deluxe Reverb from Sluckey

http://home.comcast.net/~seluckey/amps/tdr/tdr.htm

http://home.comcast.net/~seluckey/amps/tdr/tdr.pdf

isn't fine  

K

[stratele52]

Nice job Sluckey do.

[utervo]

How do you get your chassis to make themselves? That's a cool trick I wish I knew how to do.

By saying I'll do it myself and then tell my brother to do it.

Deluxe Reverb from Sluckey

http://home.comcast.net/~seluckey/amps/tdr/tdr.htm

http://home.comcast.net/~seluckey/amps/tdr/tdr.pdf

isn't fine 

Thanks, this looks great, I somehow missed it because I thought it's a 5E3 with reverb. But it is without the normal channel and vibrato circuit which I think would be nice, I can at add those there.

I wonder how accurately those original drawings are for tube sockets etc.?

[utervo]

Searching the forum I found a lot of nice files from user bnwitt of original AB763 layouts. The 6G16 tremolo mod I bumped into got me curious.

[utervo]

Does anyone know if VTL5C1 is good to use for the optoisolator in the stock AB763 tremolo?

[utervo]

I have been planning on ordering the ClassicTone transformers for both. Their EU-spec is 240V when ours in Finland is 230V, so it's roughlt 4 percent less. When rectified it will be 8 percent less voltage, am I correct? Is that voltage drop gonna make a difference?

[kagliostro]

I think it will be fine

K

[Fresh_Start]

This thread mentions a couple of noise reducing layout tips:

http://www.el34world.com/Forum/index.php?topic=7383.0

Here's thread about a Super Reverb variant I built a few years ago.  I started with the layouts and all of the work that bnwitt and HotBluePlates put together and tweaked a few things.  It's basically the Hoffman layout except that the ground bus is on the edge of the board instead of on the back of the pots.  The bias board is a unique layout too.

http://www.el34world.com/Forum/index.php?topic=7471.0

If you would like documentation in detail, shoot me a PM with your email address.

I am NOT saying this is the ultimate solution, but it was my third Blackface reverb build and the owner is very happy with it.

Cheers,

Chip

[HotBluePlates]

I am wondering if anyone here has made drawings with 100% accuracy for either Super Reverb or Deluxe Reverb?

Of the electronics and connections to transformers? Are the Fender layouts (Super Reverb   Deluxe Reverb) not good enough for you? I know, they don't show the filter caps, because they were not inside the chassis but under a cover on the outside of the chassis.

I am planning to then flip the self-made chassis into a head and have the reverb tank in the head also.

Do you mean you want the chassis on the bottom of the cabinet, with the tubes pointing up? I ask because Fender made various models in a head & cabinet format, and had the tubes pointing down. There was no change to the layout, and the circuit looked like any other blackface amp once you were looking in the open side of the chassis.

Or, you could do like Marshall and lay out everything inside exactly like Fender. Then, when you flip the chassis over to have the tubes point up, the input jack(s) are on the right side of the finished amp instead of the left side.

[utervo]

This thread mentions a couple of noise reducing layout tips:

http://www.el34world.com/Forum/index.php?topic=7383.0

Thanks a lot, it's good to keep that in mind when planning wiring. It seems a very delicate build as there is quite a lot of things going on.

Of the electronics and connections to transformers? Are the Fender layouts (Super Reverb   Deluxe Reverb) not good enough for you? I know, they don't show the filter caps, because they were not inside the chassis but under a cover on the outside of the chassis.

I have good layouts for the electrical parts now. I was thinking also about chassis drawings, where the tubes sockets, transformers etc. go. I am now pretty confident that I can eyeball them from photos when I have parts at hand, but drawings sure would make it easier.

Do you mean you want the chassis on the bottom of the cabinet, with the tubes pointing up? I ask because Fender made various models in a head & cabinet format, and had the tubes pointing down. There was no change to the layout, and the circuit looked like any other blackface amp once you were looking in the open side of the chassis.

Or, you could do like Marshall and lay out everything inside exactly like Fender. Then, when you flip the chassis over to have the tubes point up, the input jack(s) are on the right side of the finished amp instead of the left side.

Yes Marshall style with the chassis flipped. Ready-made chassises will not work as the knobs will awkwardly be facing downwards. I think it makes more sense for a head so that heat can go up. The reverb tank will be in the head also, hopefully it works upside down. How mich clearance do I need with the tank and the chassis? Output side on the preamp end I presume. Apparently there is only two options korean Accutronics or chines MOD?

[utervo]

Yes! Transformers ordered. About other parts.

The original resistors on blackface's are carbon comps.

Power and bias caps are electrolytic, the small value ones look like ceramic (single disk?), cathode bypass caps are electrolytics, what type are the blue and brown coupling caps?

[utervo]

Does anyone have original voltages for both Super Reverb and Deluxe Reverb?

[sluckey]

http://www.el34world.com/charts/Schematics/files/fender/super_reverb_ab763_schem.pdf
http://www.el34world.com/charts/Schematics/files/fender/DELUXE_REVERB_AB763.pdf

[utervo]

Thanks sluckey I have been checking those, they are accurate in "real world" also?

[sluckey]

They probably were 45 years ago. See the notice...

[utervo]

So a bit higher nowaday probably.

Is 500V caps ok for Super Reverb filter caps, the layout says 525V?

450V ok for Deluxe Reverb?

[sluckey]

Is 500V caps ok for Super Reverb filter caps, the layout says 525V?

450V ok for Deluxe Reverb?

Maybe. It all depends on how high your B+ is with the PTs you bought. I was able to use 450V caps on my DR. I strongly believe in using adequate voltage ratings in the power supply.

Many times the B+ will be higher than anticipated on a new build. "How can I reduce the B+ in my new amp?" is a common question on these forums. Where did you get your PTs? Do you have the specs for them?

[utervo]

The PT's are from ClassicTone, both for Super (ClassicTone # 40-18029) and Deluxe (ClassicTone # 40-18017) . They are for 120V/240V, we have 230V here in Finland so it will help a bit. I think it it better to put 2x350V rated in series.

Do you know if the heater wiring is on top of tube sockets because in these amps because the chassis is so low and it would be too close to reverb inputs and outputs etc. if tucked into the chassis corner like many others?

[Willabe]

Do you know if the heater wiring is on top of tube sockets because in these amps because the chassis is so low and it would be too close to reverb inputs and outputs etc. if tucked into the chassis corner like many others?

Yes.

AB763 amps have the heater wires above the tube scokets. Tweed amps had the heater wires tucked into the chassis corner.


             Brad     

[utervo]

I will have a bit higher chassis so I probably can also tuck them into the corner.

Out of curiosity, how high does B+ jump when turning an amp like this, that voltage should be the rating of the filter caps?

Also I think trying the amp without tubes when powering first time will not be possible if the filter caps are right at the limit of their voltage rating.

[Willabe]

I will have a bit higher chassis so I probably can also tuck them into the corner.

The tweed amps did not have reverb. The return signal from the reverb tank is less than the output from a guitar. I would not run the heater wires close to the reverb return RCA jack.

Out of curiosity, how high does B+ jump when turning an amp like this,

20%, 30% higher at turn on?

that voltage should be the rating of the filter caps?

Plus a little for safety margin. Wall voltage can fluctuate and can be higher at times. That will raise the B+ in the amp.

Also I think trying the amp without tubes when powering first time will not be possible if the filter caps are right at the limit of their voltage rating.

Yes, but not right at their limit, see above.


             Brad    

[utervo]

Tomorrow I'll try to find these F+T caps somewhere. Bot have all the single caps split into two caps in series to give safety margin for rise in line voltage and incase the amps are run unloaded. Capacitances will be only a few percentages off so well within the +-20 the caps are.

For Super Reverb:
F+T A-series
2 x 68uF/400V in series + 2 x 220K 4W
2 x 39uF/400V in series + 2 x 220K 4W
2 x 39uF/400V in series + 2 x 220K 4W
2 x 39uF/400V in series + 2 x 220K 4W

Actual capacitances and voltage rating or sections:
1 x 34uF/800V      
3 x 19.5uf/800V    


For Deluxe Reverb:
F+T A-series
2 x 68uF/350V in series + 2 x 220K 4W
2 x 33uF/350V in series + 2 x 220K 4W
2 x 33uF/350V in series + 2 x 220K 4W
2 x 33uF/350V in series + 2 x 220K 4W

Actual capacitances and voltage rating or sections:
1 x 34uF/700V      
3 x 16.5uf/700V   

Does anyone measure the actual capacitances when building PSU with caps in series to balance between caps?

[HotBluePlates]

I will have a bit higher chassis so I probably can also tuck them into the corner.

Don't do that. Have the heater wires in the air above the sockets like other blackface Fender amps.

The tweed amps ran the heater wiring differently than later amps because the tubes were oriented 90-degrees differently in the two series of amps.

Hold a tweed chassis and a blackface chassis such that the circuit board of each is on the same plane. You will see that the tube sockets of the blackface amp are on the same plane as the circuit board, while the sockets in the tweed amp are not on the same plane as the circuit board. If you keep the circuit boards on the same plane and turn your attention to the heater wiring only, you will see they are in the same position in both amps relative to the circuit board.

Aside from neatness of the resulting build, I believe in the tweed amps Fender was trying to keep heater wiring away from the resistors on the circuit board. High impedances (as in a tube grid resistor) can pick up hum in a strong magnetic field (such as that presented by heater wires carrying amperes of current).

It is worth noting when you build each type of amp that the heater wiring (and other power transformer wiring) is the first step of wiring a tweed amp. In a blackface amp, the power transformer wiring except for heaters is completed, then all the circuit board/tube socket/front panel control wiring, and the heaters are wired last.

[Fresh_Start]

I completely agree that you should wire blackface heater wires up in the air like Leo did.  Keep them away from the reverb return - it is a VERY sensitive signal.

I will have a bit higher chassis so I probably can also tuck them into the corner.

Don't do that. Have the heater wires in the air above the sockets like other blackface Fender amps.

The tweed amps ran the heater wiring differently than later amps because the tubes were oriented 90-degrees differently in the two series of amps.

Hold a tweed chassis and a blackface chassis such that the circuit board of each is on the same plane. You will see that the tube sockets of the blackface amp are on the same plane as the circuit board, while the sockets in the tweed amp are not on the same plane as the circuit board. If you keep the circuit boards on the same plane and turn your attention to the heater wiring only, you will see they are in the same position in both amps relative to the circuit board.

Aside from neatness of the resulting build, I believe in the tweed amps Fender was trying to keep heater wiring away from the resistors on the circuit board. High impedances (as in a tube grid resistor) can pick up hum in a strong magnetic field (such as that presented by heater wires carrying amperes of current).

It is worth noting when you build each type of amp that the heater wiring (and other power transformer wiring) is the first step of wiring a tweed amp. In a blackface amp, the power transformer wiring except for heaters is completed, then all the circuit board/tube socket/front panel control wiring, and the heaters are wired last.

My first build was a Tweed Princeton so I've always wired the heaters first, regardless of the amp.  Ooops!

Cheers,

Chip