Sluckey's AB763 Deluxe Lite Question

[dude]

I saw the schematic for the deluxe lite in a recent post and have a few questions if my PT could do this amp justice. I have, or had a Crate Vintage club 20, that I changed over to an 18 watt lite but with 6V6's and fixed bias, I'm not happy with the tone (maybe do to the fixed bias and 18 watt design, (I made the necessary resistor changes)and saw Sluckey's lite Deluxe, thought I'd convert it to the Deluxe lite.


I changed the OT to an 18 watt 8 ohm, as the old Crate had a 16 ohm but kept the original PT.


This PT only puts out 314v off the S/B, or the B+. Since I have a full wave rectifier, no room for a tube, I used a sag resistor, 120 ohm which drops the voltage to 308v to the first filter cap. (remove it?). The 6V6 plates have 304v with the sag R, is this voltage too low for this Deluxe lite to sound nice and clean, like the original?


Second, I have no choke and no room for one, used a 1K - 5 watt, will this take away from the cleans, I'm looking for.   


I'm hoping to get a nice 15 watt, little four tube, 6V6 that gives me nice cleans like the original and as the volume goes up the distortion comes. hoping to keep the headroom as clean as possible.


I just don't want to go through the work and not get what I was hoping but if I had to change the PT, I might?


The old Crate had the tubes perpendicular to the chassis, I cover the chassis holes and drilled the tubes sockets to the side of the chassis, as the board I used and the spk was too tight.


would this work = http://www.ebay.com/itm/TRIWEC-12676-1-POWER-TRANSFORMER-TUBE-AMP-GUITAR-12AX7-6L6-6V6-5Y3-12AU7-5E3-/222498477725?hash=item33cdf1569d:g:U4gAAOSwr7ZW4g2h


Thanks in advance,
al 
     

[sluckey]

I think your voltages are too low for an AB763 Deluxe. The amp will work with only 300V B+ and may sound OK but I would expect it to sound different from an AB763.

Surely there's room on the outside of that chassis for a small Fender choke. Just don't put it in the preamp area.

I would build this with the PT you have. Nothing to lose and you may like it. But I'd be prepared to replace that PT with a higher voltage one.

[dude]

What coke would I use, does Doug have one?


Is the coke pretty much necessary for the tone I'm hoping for? Don't know much about a coke except it drops voltage.


Yeah, I could try the low voltage PT, but it's a stand-up PT, as you can see impossible to use a lay down. In the past I've found a stand-up PT hard to find, could you recommend something that will give me the correct voltage. Maybe ebay I could find some thing, I assume I'd need something like 300-0-300, maybe up to 325-0-325, but everything is laydown..?   Assume I'd need around 400/410v B+, 300 too low?


Perhaps, the reason I don't like the tone now is that low voltage, just not real clean and the volume is kind of low for an 18 watt Superlite...?


BTW, I have a Weber 290-0-290 lay down in my parts box. I think still if I could get that converted to a stand/up, the voltage would only be 340v at max, too low...? 


Thanks,
al

[sluckey]

You definitely need the Real Coke. Don't bother with that New Coke. Doug has exactly what you need. Take a look. I'm sure you'll find it.

Don't know if Coke is necessary but every AB763 amp has one. Both of my AB763s have one.

There are plenty of standup style PT with the appropriate voltage. I would buy this one for a Deluxe Lite...

https://www.tubesandmore.com/products/transformer-hammond-power-300-0-300-v-144-ma

[dude]

You definitely need the Real Coke. Don't bother with that New Coke. Doug has exactly what you need. Take a look. I'm sure you'll find it.

Don't know if Coke is necessary but every AB763 amp has one. Both of my AB763s have one.

There are plenty of standup style PT with the appropriate voltage. I would buy this one for a Deluxe Lite...

https://www.tubesandmore.com/products/transformer-hammond-power-300-0-300-v-144-ma

All I have here is diet   hey, a donald trump moment .


Big difference if the choke it's 9H or 4H,  I have a small 9H, 120ma here. I could make a bracket for that Weber lay down I have, has two HV taps, 540v and 680v, which tap is best? It's 150ma


thanks,al

[sluckey]

One is too high, the other is too low.

[dude]

Yeah I figured that, the 540v probably a B+ of 340v with SS Rectifier and the 680v probably 430v, too high or higher w/diodes R.


Think I could use the 680v taps and use two or three 5 watt, 15V zeners in series, to get around 400v B+?


I've used them on the B+ and CT ground, would either interfere with fixed bias?


I appreciate the education, what about that 9H choke
al

[sluckey]

Think I could use the 680v taps and use two or three 5 watt, 15V zeners in series, to get around 400v B+?

I hate that idea. It just means you chose the wrong PT to begin with.

I've used them on the B+ and CT ground, would either interfere with fixed bias?

If you put the zeners on the CT they will affect the bias voltage.

I've made some good suggestions on how to successfully build this. You seem to really want to build with the iron you have. I totally get that. Just do it. You may be pleasantly surprised. If not, let's revisit once you have it built.

[dude]

I get it, if you're going to build, convert an amp, do it right.


And you're right I'm trying not to put the cash out for the correct PT and choke, that's it.


You got me thinking, it's not as much whether the build plays, it's the pride in the build being done right.


Thanks, I'll do your Deluxe lite and thanks for posting the schematic and advice.

[dude]

 Steve Sluckey,


Regarding your Deluxe Lite, I used  the Hammond 272DX you suggested, spent the money, used a coke, I mean I drank that and added a choke, . Tapped the bias correctly, added bias points (1 ohm's) to outside the chassis with the bias pot. Almost done but since I have a level volume pot on this Crate Vintage Club, I wanted to put a master there. I can just put a 500KA pot before the PI, as you suggested in another post or I can add a dual 1MA pot after the PI.

In your opinion, if this were a build you were building today which would you use? Am I correct that the post PI MV would basically be more of a volume pot just lowering the overall volume and the before the PI would interact more with the main volume pot?

thank you,
al