NAD, kinda - Epi VJ Baby Will conversion

jimijames

New member
So, I've probably made a comment or two about how my epi valve jr. was torched. Well, turns out it wasn't. More on that later.

I ordered this pc board, and on that site they have all the documentation for all the parts.

I ordered everything, busted out the soldering iron, etc. Total cost on top of the valve jr. was probably in the $150 range.

I'm still waiting on a 12ay7 to arrive from amazon. Right now I've got a 12at7 and a 5751 in there. I finished the build tonight (or last night as it were) and I can't turn it up all the way until around 9 am tomorrow (live in an apartment complex, noise rules and the like)

A lot of times I try and pretend like I know guitar electronics. Don't be fooled, I'm still very very new to everything. At any rate I thought the old VJ was dying because of the capacitors in it - turns out the guy who had it before me added a second fuse - which is a great idea to protect the expensive bits of the amp, but the first one is starting to let go which made me think the amp was breaking. Discovered that today after firing up the baby will.

I played a HS telecaster and a SSH strat through it (p-rails for the bucker though) - I can't turn it up loud enough to get it to distort yet (even though it's only 18 watts there's still plenty of volume to wake the neighbors), but so far I'm really, really enjoying it.

First Impressions: Lots of bass. I've been playing with the volume at 25% and the v30 (which isn't a very bassy speaker to begin with) does shake (very slightly) some of the stuff in my room when I hit the low E. With the 12at7 and the 5751, the sound isn't super marshall-y - but it doesn't nail that fender sound either. Kind of in between the two IMO.

It's very touch sensitive. Especially noticeable is the difference in timbre when you switch from a pick to your fingers - it doesn't exaggerate the change but it doesn't hide it either. I've played amps that really emphasize dynamic changes - soft vs. hard picking and the like - while this guy doesn't exaggerate everything, it doesn't hide it either. It's a very 'transparent' amp which sounds weird to say but the color of the tone is attributable in very nearly its entirety to the guitar. The strat I played through it has strabro 90s and a p-rails and each position is markedly different. The strat neck sound is clangy and sweet, the full output (p-90) is fat and vocal. If you really squeeze the notes the sound gets thick in a hurry.

The telecaster has a splittable humbucker in the neck and a jerry donahue in the bridge. I wish I could wire it to get series/parallel/split but I don't want to drill the pickguard for a 3-way mini. So for now, it's series/split with a push-pull. I wouldn't call this a really country sounding amp - my poor approximation of chikin pickin was fairly generic even in the middle position with the bucker split. For some reason, the bridge pickup sounds louder relative to the neck than in my (soon to be sold) 50w plexi combo. I'm not selling it because it's a bad amp - I just don't need anywhere near 50 watts, and the Baby Will has better cleans. We'll find out how the distorted sound is tomorrow (later today actually).

I haven't put it back in the chassis yet, but here's a photo:

IMG_20130907_241015_128_zps36cf65d2.jpg
 
Re: NAD, kinda - Epi VJ Baby Will conversion

So you added a:
Pre tube
Power tube
Tone knob
And got a whole new tranny set as well.?
Wait a minute...that PT has slide connectors...it is a replacement though...right.?
 
Re: NAD, kinda - Epi VJ Baby Will conversion

New OT, same epi valve junior PT.

New circuit board and components and such. You only reuse the chassis and the PT pretty much. You have to use one of the little plastic wire guidance things where the PT wires go through for the new OT - that's why the two leads are above the chassis. You also have to drill out like 5 or 6 new holes. The 20w OT is smaller than the 10w single ended hammond I had in there before.

FWIW I got to open it up volume-wise and it sounds good. Right now there's a 12at7 and a 5751 in the preamp. Those two distort less than 12ax7s so it's more power tube distortion. You don't get more volume but it starts compressing a little over halfway up the volume knob. You have to get a matched set of el84s so I've got two spares now (the crap tube that came with it and a single JJ el84 that I put in there before it stopped working.) The distortion could be a tad 'softer' but when those power tubes are hot it's absolutely tasty.

The cleans are really nice. I'm kind of curious now about the 5e3 circuit which is basically a DIY 15w fender champ that people like a lot. But, if I'm being honest I can't see how it's that much better. Cranked this amp has a very led zeppelin/acdc/zz top distorted sound. Kind of vocal with a really meaty growl. My telecaster sounds huge on the bridge pickup and very smooth and fat on the neck. Maybe too smooth but I'll live with that. The note definition is unreal - a friend was playing jazz chords through the amp cranked and I about wet myself.
 
Last edited:
Re: NAD, kinda - Epi VJ Baby Will conversion

Single ended OT are kind of big....guess it is the gap.
Anyway....so the stock PT has no problem with the extra current draw from the heaters of 2 more tubes.?
Seems like you have played yours quite a bit...so I guess not.
Nice work.
best
 
Re: NAD, kinda - Epi VJ Baby Will conversion

Honestly, I've only got about 10 or 15 hours so of playing time on the amp. Is there a break-in period? I've heard for speakers there is but I have no idea about the actual amp itself. Most of that playing time has been at 15-25% volume with 2-3 hours at around 75% volume.

So far the PT has held up like a champ. I'll update the thread if it lets go. But I did it as per the baby will instruction manual which didn't have a PT on the list of required parts. I don't remember the current draw for the heaters off the top of my head.
 
Re: NAD, kinda - Epi VJ Baby Will conversion

I ask...because you have 2x the current demand.
In most cases...that would kill the PT.
I would think your PT would get real hot within 1 minute if it were a problem.
That PT may have been under used in its stock from...who knows.
If it does not get too warm...I would say you are home free.
Anybody that could design that PCB... draw up a list for parts and spec a new OT...would certainly be capable of diagnosing the stock PT.
Cool little amp.
I have 2...a head and a combo.
The head I modded in its stock from.
The combo I bought a turret board for.
New OT in both.
Lots of options with a Valve JR.....always have my eye open for a CL steal.:)
best
 
Back
Top