A little Valve Junior Renovation

[Southpaw Tele]

Well, we stayed home this morning with a sick child, so I had some time to snap and post pics of my half-butt lead dressing.

What NOT to do:

and some more...


I'm going to clean up "The Mess" (as I'm now referring to the amp) and then post more pics.

[JohnnyCrash]

That's a clean and neat PCB!

Heck, just shortening those wires (just to-from the input, volume, and tone) should kill the squeal. Route the other wires away from the preamp and use a cable tie to keep them bundled away neatly.

Don't worry about the heater wires' angle. As long as they're twisted you'll be fine. They do not carry signal, but they do run AC voltage (AC will give you low frequency 60 cycle hum).

Since the amp is cathode biased, if hum continues to be an issue, there's one or two more tricks we can still use...

[Southpaw Tele]

Thanks! Okay, I twisted the wires (for the heater) and I'm still getting hum. The squeal is gone, which is weird because I haven't touched the wiring for the pots or input yet. I know version 1.3 had a hum balancing trim pot, but this version didn't call for one...still too newbie to know why lol

Would a sound clip help at all?

Also, I need to PM you a beer or a GC gift card for all the help.

-Matt

[Southpaw Tele]

On another note, I'm realizing how tough it is to work with tolex. I've made an extension cab before, but I used a vinyl covering that wasn't nearly as inflexible as real tolex. I'm really wishing I'd gone with a stain on the pine...grrrrrr...

[JohnnyCrash]

Originally Posted by Southpaw Tele

Thanks! Okay, I twisted the wires (for the heater) and I'm still getting hum. The squeal is gone, which is weird because I haven't touched the wiring for the pots or input yet. I know version 1.3 had a hum balancing trim pot, but this version didn't call for one...still too newbie to know why lol

Would a sound clip help at all?

Also, I need to PM you a beer or a GC gift card for all the help.

-Matt

The 1st thing I have to ask is, does the PT have a heater center tap? A balance pot for the heaters? Hmm, it might be an option to put your heater CT or artificial center tap on the power tubes' cathode (before the resistor/cap) to DC elevate it.

I'd shortent the leads preamp 1st, then see how the hum is... we'll figure this out soon.

[Southpaw Tele]

No center tap on the PT. How do I do the artificial center tap on the cathode?

[Southpaw Tele]

k, this is from Terry over guitar amplifier pcbs:

"Version 2.3 of the Baby Will uses two 100 ohm 1% resistors to create a DC elevated artificial center tap. They run from each of the heater traces to the power tubes' cathode with operates at around +10Vdc, thus the dc elevation.

So the hum balance pot isn't necessary for version 2.3. It's much simpler this way.

I hope this helps.

Regards,
Terry Stinger"

I have those in already, so I'm resoldering them and shortening the leads.

[Southpaw Tele]

Now I'm getting discouraged...I shortened the leads, resoldered the ACT resistors and still getting over the top hum...AArrrggrghhhh!

[Southpaw Tele]

Well, Terry Stinger from Guitar Amplifier PCBs (www.guitaramplifierpcb.com) helped me out tremendously. I am in no way affiliated with the company; just a very satisfied customer. There was an issue of jumpering the input points on the pcb. This amp is QUIET (hum wise), even with the standard MIM Tele pickups. As soon as I finish the cab, I'll post pics and some sound samples. I'm loving this thing right now...LOUD!

[JohnnyCrash]

That's awesome news Southpaw Tele!

I know you were concerned about headroom for the hall you play in. Does it seem like you'll have enough clean volume now?

[Southpaw Tele]

Originally Posted by JohnnyCrash

That's awesome news Southpaw Tele!

I know you were concerned about headroom for the hall you play in. Does it seem like you'll have enough clean volume now?

Plenty of headroom JC...the sound guy and the worship leader asked me to turn it down for the first time ever lol You were right about 18 watts being on the loud side.

Again, thanks for all the help on this guy...pics coming soon. Terry Stinger's a standup guy, as well.

[Southpaw Tele]

Well, here is the completed package (for now...thinking of installing a line out, maybe a redo on the baffle, buying a proper faceplate, etc.). I built the cab from some cheap Home Depot wood myself with minimal tools. I used a simple jigsaw to make a finger joined cab and then covered it with some brown tolex that was on sale at mojotone. Grill cloth was also an "on sale" from mojo. Speaker is an Eminence Lady Luck 16 ohm 12" that sounds good to me.

Faceplate is temporary. I bought some inkjet magnet sheets from Office Depot and had to print on two sheets because the chassis was too wide (which explains the line near the middle).

There are some obvious flaws and borks (JohnnyCrash, that was for you, btw) but I'm happy with my first build. Thanks again to all who helped me out on this...I'm truly thankful for the TDPRIers.

[Southpaw Tele]

Oh, btw, the cab is not the one I originally built. It's more of a Deluxe Reverb sized cab. The front panel "cover" is pine done up with some honey pine stain/poly. I really like the Dr.Z's with the wood panel covers, so that was my inspiration. Unfortunately, it looks nothing like one and the quality is horrendous. All the cuts were with a jig saw and standard round saw (and even a handsaw in some instances). I highly recommend getting the proper tools when building a cab. Doing finger joints with a jigsaw is time consuming (though, there is a thread where one of the TDPRIers did the finger joining with a hand saw).