Snow has fallen in my neck of the woods so it was time to get back to it! Plus, I have a pretty good reference on how it sounds to this point in time.
Here‘s what I started with.
The stock board.
First off, change the caps.
I chose these Jupiter caps from Antique Electric Supply because they seemed to get good reviews. And, I liked that they say, “Vintage Tone”. For the PF values I used the ”Silver Mica” ones from the same place.
I was going to stop here and give it a listen for a while. I did kinda want to hear any changes before replacing the resistors. That way I could report on how each would impact the sound. But,,,,
I was having too much fun! So I went ahead and replaced the resistors too.
PRP 1% metal film from a place called “Sonicraft”. A little pricy, but not a budget buster.
I have read that some people complain the stock board is difficult to work with. Reports abound about lifting doughnuts while removing parts. I’m happy to say I had no trouble whatsoever! Using my Stahl vacuum desoldering/soldering station, set to 550 degrees, I was able to open up the holes big enough to drive a train through! Leaving all the doughnuts firmly attached to the board. It actually was a pleasure to work on. Plenty of room between components. Almost no possibility of creating any solder bridges unlike other boards I’ve worked on.
The solder side of the board
After completing the work I checked the bias and found that I had to turn it down quite a bit. I did have it set at 1.56v before starting this work. Checking it after the work I found it to be as high as 1.8v. I started to worry I would not have enough range on the pots because it was already on the counterclockwise side of the midway point of the pots. Not to worry though, a small tweak counterclockwise and it went right back down to 1.56v. It also seemed to drift less. Staying between 1.563v and 1.558v or so.
And lastly, the replaced parts shot. Gotta have one of those!
This did take the better part of the whole day. The difference between an amateur and a professional is the speed at which he does his work. I am an amateur!
I did get to pump a few songs through it. My initial impressions is there is an increased “Presence” of a centered vocal. Seems to float between the speakers in a much more focused manor. Not that it was bad before, but definitely better now. In the bottom end the “Vintage Tone” written on the caps seems to be true! Much more tone on drum wacks than before. The “Silver Micas” also seem to be doing their job. On Buddy Holly’s song “Everyday” the chimes seem to have more sparkle, more “Tinkle”. Lastly, I’m very impressed with the shear power it displays. I was always under the impression that one needed at least 100 watts. This amp has dispelled that myth for me. 35 watts of EL 34 power is plenty!
All in all, I’m very happy with the outcome! This amp is definitely a keeper!
Thank You sincerely to all that have followed my Journey and to those that helped me along the way. (You know who you are). It’s time to put a few more hours on it and try to determine if “Cap Break In” is really a thing. LOL!
And,,, time to look for another project! Later, Mark
, 
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