What's on Your Workbench?

Slow progress: after cutting off the board and re-soldering (it was a bit too wide) everything except the heaters and input/output seems to be done. The amp is built pretty tight - four input modules of that size, in the middle the mixing stage with additional inputs for reverb and tape recorder (or a keyboard) and the PI stage all fit into a narrow space.

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bea said:
Fitting the large parts - German amps from the 60s often have been super compact.

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Yup, she looks tight.

I have a David Eden Bass head, a Laney 50 Watt AOR, and a Marshall 100 watt head to revive. They are all in line along with several lawn tractors, several houses, my pickup truck Water Pump, Timing set, Radiator, Oil pump and a few other vehicular repairs on numerous 4 and 6 weel units before during and after Winter socks us in.

Good luck bea.
 
As usual, my workbench is more than full. The amp, some fine tuning/maintenance on my basses (mhmm, the Sharkfin needs a low impedance pickup, thinking how to make a stacked humbucker and a preamp), the amp(s), a new speaker for one of my cabinets, a fender for the rear wheel of my velomobile and still the top for the velomobile of my partner:

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Gehen Sie zurück auf Los. Streichen Sie keine 4000 Mark ein
(famous Monopoly event in German translation...)
bea said:
Slow progress: after cutting off the board and re-soldering (it was a bit too wide) everything except the heaters and input/output seems to be done. The amp is built pretty tight - four input modules of that size, in the middle the mixing stage with additional inputs for reverb and tape recorder (or a keyboard) and the PI stage all fit into a narrow space.

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Ther seems to a a pretty weird error in wiring the module: even with no tube installed it causes a drop of the output voltage to about 50%, from 240 to 120 V.
Which probably means that i will entirely have to remove the wiring and set it up almost from the beginning.

Well, a bit frustrating... But having this clear information is important for a good final result. I will probably run this through spice (and the original module as well) and further optimize it. Luckily there is currently no pressure (anymore!) for a quick progress.
 
Finally got around to trying out this set of used Gibson '57 Classic pickups I got a little over a year ago. the stickers are dated 2019. I didn't want to cut off the plug-in connectors so I put them in my SG.

Like these a lot. They are different from the 490R/T stock set. Much brighter / less bass / a bit smoother / more note separation as gain is applied.
I guess more vintage PAF than 490 Modern PAF.

I still like the 490's as well: different, not especially better or worse.

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I added a presence function to my 4210 over the weekend to make it more like the 2205.
The 4210 has a fixed resistor where a potentiometer can be placed on the board.
2205 specs call for a B22K pot - 4210 schematic shows a 3K3, but mine has a 3K9.

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Rummaged a B22K pot from the stash and put it in where the DI level pot is on the back panel.
Just pulled the DI pot in and zip tied it down, so it doesn't rattle around.
Removed the fixed resistor and ran some wiring around from the board to the new pot.

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It works great!
Nice sweep from bright to warm with one knob.
Not exactly convenient to reach around the back of the amp for adjustments, so I may relocate.
Keep in mind, my 4210 chassis is inverted in a head shell...

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Found a pic on eBay of a 4210 for sale that has the presence mod with a direct mount through the faceplate.
It's a tight fit right up next to the standby switch.
I'm thinking maybe a mini pot with a smaller black knob might look kinda balanced with the input jack on the far side?

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bea said:
t is time to work again on my old PA amp...
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Looks as if i'm done for now. The new module works as it should, and i installed new power tubes.

As already mentioned, the new module uses a ECC82 in connection with the tone controls of the Little Bea_R amp (AMZ one knob control + adjustable notch filter and fixed treble emphasis through a cathode cap). All in all pretty Hiwattish, as desired. Now i have three inputs on the front: two Mic/High impedance general purpose inputs plus one guitar input. And two line level inputs on the back.

The new power tubes are KT77 instead of the EL34 the amp is designed for. At 750V on the rails. The KT77 are sufficiently similar to the EL34 in order to be usable even under those rough conditions. Data wise, not technically: the EL34 is a true pentode while the KT77 are beam power tetrodes. Not all of them run stable in this amp, but these two tubes do - thoroughly tested. The pic below shows the voltage drops at the cathode resistors (10Ohms), i.E., the cathode current.

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Well it looks like this is back on the bench. I was going to sell this guitar, but after my neck shaving thread I realized that this guitar has the perfect size neck for my hands. So I started playing it again, but I need to fix a couple of things. It's really a great guitar, but my 2 gripes with it are the frets are too low, and the PCB is too limiting. I like the pickups that are in it ok, but I don't love them. I also prefer a 330k bridge volume pot and it irks the crap out of me that I can't just swap it out. So I bought an RS guitar works wiring harness for it (Vintage upgrade) and had him do a 330k bridge volume pot for me. Once I get it rewired and have it set up with the pickups I like best in it I'm going to take it to my guy to have it refretted with some fatter frets. Then maybe I'll be able to answer all the "what is your #1 threads". :fingersx:

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DirtySteve said:
Well it looks like this is back on the bench. I was going to sell this guitar, but after my neck shaving thread I realized that this guitar has the perfect size neck for my hands. So I started playing it again, but I need to fix a couple of things. It's really a great guitar, but my 2 gripes with it are the frets are too low, and the PCB is too limiting. I like the pickups that are in it ok, but I don't love them. I also prefer a 330k bridge volume pot and it irks the crap out of me that I can't just swap it out. So I bought an RS guitar works wiring harness for it (Vintage upgrade) and had him do a 330k bridge volume pot for me. Once I get it rewired and have it set up with the pickups I like best in it I'm going to take it to my guy to have it refretted with some fatter frets. Then maybe I'll be able to answer all the "what is your #1 threads". :fingersx:

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I’ve gotten 3 kits now from RS Guitarworks. Two guitars and a bass.
 
I originally bought that harness for another guitar, my cursed 2013 Tribute. I've wired many guitars over the years with no problems, but I've completely rewired this guitar several times and it always dies on me. I figured I'd try a good wiring harness and see if it worked, but I decided instead to follow Headache's lead and just put a bridge pickup in it with a dummy neck pickup. So, a few weeks ago I wired it up with nothing but a bridge pickup and a volume pot, no neck pickup, no switch, just a pickup, jack and a single volume pot and it's dead as a door nail. I just don't get it. I have to believe it's cursed, I've got no other explanation..

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DirtySteve said:
Well it looks like this is back on the bench. I was going to sell this guitar, but after my neck shaving thread I realized that this guitar has the perfect size neck for my hands. So I started playing it again, but I need to fix a couple of things. It's really a great guitar, but my 2 gripes with it are the frets are too low, and the PCB is too limiting. I like the pickups that are in it ok, but I don't love them. I also prefer a 330k bridge volume pot and it irks the crap out of me that I can't just swap it out. So I bought an RS guitar works wiring harness for it (Vintage upgrade) and had him do a 330k bridge volume pot for me. Once I get it rewired and have it set up with the pickups I like best in it I'm going to take it to my guy to have it refretted with some fatter frets. Then maybe I'll be able to answer all the "what is your #1 threads". :fingersx:

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Phase 1 complete. I don't know if it's due to ditching the PCB for a normal wiring harness with my 330k bridge volume pot that I like, or just swapping the pickups, but I'm very glad I did this, it's a big improvement! Not sure I like the look of the zebras in this one, but these sounded best. I took these out of my Standard because I'm putting back stock to sell. I do have a double black of the same bridge pickup (it's in the cursed LP I posted above, lol, 'cause I'm not ready to give up on it yet), but I'll wait to see if this look grows on me. I does look better in person than in this pic.

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DirtySteve said:
Phase 1 complete. I don't know if it's due to ditching the PCB for a normal wiring harness with my 330k bridge volume pot that I like, or just swapping the pickups, but I'm very glad I did this, it's a big improvement! Not sure I like the look of the zebras in this one, but these sounded best. I took these out of my Standard because I'm putting back stock to sell. I do have a double black of the same bridge pickup (it's in the cursed LP I posted above, lol, 'cause I'm not ready to give up on it yet), but I'll wait to see if this look grows on me. I does look better in person than in this pic.

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I think that it looks great!!!….but I have a soft spot for zebras…
 
I'm not as impressed with RS Guitarworks as I thought I'd be, there's a lot of hype for RS, but I don't really think there's anything all that special about the harness. It is better than Mojotone harnesses I've tried. I'm pretty sure the caps need to be swapped out for orange drops, which I meant to ask him about, but I forgot after I had to assure him that I did know what I was talking about when I asked about a 330k bridge volume pot, he thought I was nuts until I explained to him that I always prefer a 330k pot for the bridge volume and I do it on all my guitars. I guess the neck tone cap is ok, but the bridge tone is all or none and all is too much. I might just lift it, I rarely use the bridge tone knob anyway.
 
Well my bench is a wreck as I had a near disaster with a leaky roof dripping on my bench and computer desk. So things are just dumped out still. I just got the computer and speakers and interface put back together and it seems I am able to make everything work. So now I get to re organize stuff. The only thing really damaged is one monitor that still works but it swelled up and the laminate it blown out and it doesn't sit right and is wobbly. Got lucky though, could have been worse.
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C-Grin said:
Well my bench is a wreck as I had a near disaster with a leaky roof dripping on my bench and computer desk. So things are just dumped out still. I just got the computer and speakers and interface put back together and it seems I am able to make everything work. So now I get to re organize stuff. The only thing really damaged is one monitor that still works but it swelled up and the laminate it blown out and it doesn't sit right and is wobbly. Got lucky though, could have been worse.
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Your bench looks a lot like mine. :rolf2: :rolf2:
 
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