whoops

I hope to do some updating in the coming weeks.

I've been taking and editing some photos in prep for adding some updates here. Projects to be discussed are my mid 60's Spanish Jomadi, my late 50's/early 60's Harmony and I'm not sure what else as of yet...

Jomadi...

From Jomadi

Rocket...

From Harmony Rocket

Ach...it's been ages.

Haven't updated in a long time. Not that I haven't been busy doing things and with life, but I just haven't been diligent recording it all here. I'll try to do some catch up in the coming weeks. I suppose a good place to start would be the latest addition to my Gretsch stable.

I found a listing for a "1965 Corvette project guitar" on one of the forums a few months ago with no price. When I e-mailed the guy and asked how much, I was surprised at his answer. It raised my suspicions there was more than met the eye wrong with it, but I decided to go with my gut feeling and make the buy.

Once it came in I knew why I got it for $450. Broken headstock. It's not the most elegant repair, but it has proven very strong and the guitar seems to suffer no ill tonal effects from it. Otherwise it was a great deal. All original except the pickguard, pots and knobs. I also got a spare set of Van Gent tuners, a spare trapeze tail piece as well as a good condition original `63/`64 pickguard. Plus a old set of Grovers I need to sell that might bring some coinage.

Really, all the guitar needed was some TLC and assembly plus a few parts. The pickguard had disintegrated and corroded many of the metal pieces on the body. The screws where so bad, extracting their remains was one of the bigger jobs. I used a soldering iron to heat them, then backed them out with some pliers. None broke, no damage to the body, so it went well.

After a thorough cleaning and polishing of the body and frets, I cleaned all the metal bits which took a good deal of time. Then I got it assembled and added some modern knobs and added a pickguard repro I took a chance buying from ebay. It ended up being a perfect fit, so I got lucky.

Now, it's one of my favorite players. I keep it at my girlfriends so I can play on the weekends, That 1965 Hi-Lo Tron sounds freaking glorious. I played this guitar at my band's (IDK) last gig through my Silvertone 1484 with both channels jumpered and completely cranked. I was sooo happy with my tone that night. I also did my first solo with IDK on it and got some nice compliments afterwards. All in all, a fantastic addition to the stable.

Here's a gallery with some photos of it before and after (click on the pic):

From 1965 single pup Corvette

ZZZZZZZAAAPPPP!!!!!

Yup, my first time getting zapped. Luckily, it was very mild. I've been working on my Silvertone 1484 head. I had drained the caps, but disconnected the drain resistor and the main filter caps had built back up a little charge...which I found when I was probing around the choke to make some changes to the standby switch. Little tiny spark and a very small jolt....but it was still memorable in that it scared me. I suspect if it was the old original Atomics in there I would have been OK, but they where brand new eletrolytics I'd gotten from Weber, so they where fresh and eager to do their job. Trying to remember to keep the drain resistor hooked up when working on my amps now....

So, yeah....I'd put together a project list at Mouser for the 1484 head (number 1) that consisted of every resistor and capacitor. It would've come to a bit over $100 if I'd pulled that trigger. One day I was looking at Weber's site....and saw they carried resistors and capacitors. Hmm...so I put together an order for everything and it came to less than $40! Trigger pulled!

The parts came in over last weekend, so this week I've been digging in the Silvertone. Let me tell you. working on a point to point terminal strip amp is a major bitch. I was trying to properly desolder and remove all the components I wanted to replace, but there are times I just had to cut leads and find a way to make a good connection on the terminal strip. I also ended up needing to splice wires a number of times to extend them, versus completely replacing the wire. Not pretty, not the absolute best lead dress, but it worked.

I'm not done with the 1484 yet, but making good progress. All the electrolytics are new. New power cord, ground switch dissabled. Some of the crappy ceramic disc caps swapped for polyesters. Slowly going through and checking resistors. Best part is, I test my work from time to time and it's all good thus far. I still have some caps I want to replace, and a lot of resistors to check, but it's sounding great and the reverb and tremolo are working...as well as can be expected anyway.

One major thing I did was to change the standby switch to a Fender style. The original was just strange in that it shorted the phase inverter together. I moved it to right before the choke, much like most Fender amps. Much better, IMHO. Screwed up initially though...I disconnected the wires from the standby switch and, without thinking, spliced them together before moving on to changing the switch over. I had done this along with a number of other things, and when I fired the amp up it wasn't working properly.....very, very low output, almost none at all. Uh-oh...

I checked everything over twice and checked all solder joints...and couldn't figure out what was going on. It sounded familiar, just like it did before the standby switch change when the amp was on standby, actually. I remembered this and did some googling....and realized I should have just removed the old standby switch wires, not splice them together...because in doing so I hard wired the damn amp into permanent standby! Ha! It was late....give me a break.

Anyway, I've created a album with some photos....and here's a link showing my revised schematic...changes noted in red, components R&R'd or revised (thus far) highlighted in yellow..I will update this as I do more. Tremolo circuit next!

From Silvertone 1484 #1

A lucky Bassman Ten owner!

It's been a long road, but I think I've just about finished working on my Bassman Ten. It's been a real learning experience!

I noticed, over the last couple months, it just wasn't as loud as it should be, or as I remembered it when I first got it. So last weekend I decided to try to figure out the overall health and finish up any maintenance it needed.

I started by pulling the chassis and taking voltage readings everywhere. I had located a recently redrawn schematic where you could clearly read all component values and voltage levels. Everything was within the Fender specified +/- 20%.

So I hooked up my Weber Biasrite to check the bias voltage and current and was very surprised to find .6mA on one powertube and 12mA on the other. It should be closer to 30 to 40 mA! It didn't seem loud because it was only making around 7 watts from 2 6L6 tubes!

Turns out the screen grid resistors had gone open. Some idiot had used 1/4 watt resistors in place of 1 watt resistors and the heat had caused them to go open! That idiot was me, apparently, but I honestly don't remember doing it and don't know why I did! I was very lucky they didn't short. It might have fried my brand new Weber output transformer I think, or at least the new JJ tubes in there.

So I replaced those (with 2 watt metal films), a few other resistors and finished swapping out all the electrolytics. I kept stock values on everything except the cathode bias bypass capacitor which sets the bias level of the second half of both preamp tubes. It was 5µF stock and I upped it to 22µF (62 volts).

I finally removed the death cap and put in a new power cord too. Someone had installed a grounded cord a long time ago, but never disabled the ground switch and removed the death cap. That's all done now. If there's anything left to do, it's swap out all the old diodes. I'm gonna ask around and find out opinions on that. They're around 30 years old now and I wonder about them holding up.

I should also check every carbon comp resistor I've got left to see if they've drifted too far, but I'm in no huge hurry for this because it sounds great, the voltages look good and I have no excess hum or noise. All the critical ones in the power section are new metal films, as well as a few others here and there.

This is really a very cool amp. It's pretty unique among Fenders. Channel two is voiced very close to a AB165 Bassman, Channel one seems to be pretty unique voicing (much darker than two) and the overall topology is close to a Bandmaster without Vibrato. Basically, it lacks the third 12AX7 gain recovery stage of a Bassman (and many others) before going into the 12AT7 phase inverter. Take the vibrato circuit (and tube) out of a Bandmaster and you have the same overall thing.

It's not a loud amp, especially given the two 6L6 tubes, and with the bias being fixed kind of cold, it's only pushing about 32 watts right now. The tubes should last a good long time. I may, at some point, convert it to adjustable bias and work those tubes a little harder, but I'm in no hurry. I think it makes a great rock amp as is...jumper the channels and you get rich distortion at reasonable volume levels. It's kind of difficult to describe the sound, but if you read up on the Bassman Ten around the net, you'll see most agree it sounds great and absolutely unique among Fender amps.

I'll eventually flesh out my blogger photo folder for it, but for now here's one overall shot (notice it's a head now, not the typical 4X10 combo), and a link to my photobucket account for it...

From Bassman Ten

I'm going to try to recount a list of everything I've done to this pawnshop prize here...

All electrolytics replaced
power cord replaced/ground switch dissabled
new tubes and bias balance set
all new screen grid resistors and power rail dropping resistors
new speaker output jack
new output transformer with only 8 ohm tap used
new head cab
negative feedback resistor upped to 1.2k (I think, it was upped anyway)
all mods from previous owners reversed or eliminated

There are a few I may have missed and a few more (like diodes and maybe adjustable negative feedback) that I may yet do.

All in all...very cool project!

Adventures in amp land

So it's been amp fest for me this week. Two and a half nights of playing my fingers off and annoying the neighbors.

I started out with the Peavey Triumph 60 and 1975 Fender Bassman Ten, one stacked on the other and both running hooked into my Marshall 4X10 (1965B).

That Triumph doesn't have what I'd call Fender cleans, but it's still pretty damn nice. Being able to switch between three channels is awfully fucking cool. Loves pedals, the crunch channel is quite versatile and dialable and the ultra channel is more gain than I typically use...which is great fun. Really glad I have this to fool around with, especially at the price I got it for.

The Bassman is simply not as loud as it should be. Given it has 2 6L6 tubes. I got to looking into that here at work and at home and figured out the replacement transformer is a 4ohm tap (only). So, all this time it's been running as a (more or less) 20 watt amp. No wonder! I don't have a cab wired for 4 ohms at the moment, and am thinking of getting a new Weber output tranformer for it. They're around $60 and would have 4 and 8 ohm taps (and maybe a 16 too).

My Cool Cat Drive came in and I've been messing with it the last two nights. It's pretty damn noisy with the Bassman, but quiet with everything else.(head scratcher) Regardless, I like it a lot and it's interesting to turn the gain all the way down, the volume all the way up and use it as a clean boost. I have a Transparent Overdrive (first gen.) on the way and am really looking forward to A/B them in that mode. Lots of gain on tap too if you push up the "Drive".

Then, last night I dug out my spare Silvertone 1484 head. It worked last time I played it a few months ago, but didn't seem loud enough then and I was nervous about a number of things. I've since found out the output transformer has a second tap at 8ohms that can be hooked up. I did that, replaced the kinda broken speaker jack and then put a better three prong power cord on it. It's as loud as it should be since the output and speaker cab impedances match up now.

I'd seen that Weber sells a replacement output transformer for these too and it's not very expensive, so I figured I might as well have some fun playing it till I get a chance to clean and do some recap work on it. If I blow something, it won't be a huge deal to fix it.

It was really acting up last night though and was making lots of scary noises...so I figured I'd fucked up somewhere or age and dirt finally got the best of it. In an attempt to start trouble shooting, I grabbed a chopstick and began whacking tubes to see what would happen. Damn...V1, the first gain stage 12AX7, made a shit ton of noise when I tapped it. It'd gone microphonic in a big way. No idea what kind of tube it is, can't see any markings, but all the others are original Silvertone tubes. I yanked it out and stuck a ElectroHarmonix in there I had laying around. Ding,ding,ding! No more noise at all!

God I love these (Twin Twelve) amps. I really like having a spare at home I can test pedals and guitars with. It's not exactly like my gigging amp, in part because I'm running it through the Celestion G10L-35 speakers instead of the old Jensens, which I think are much less efficient. I can hear the lack of speaker breakup at home. I also figured out my Vox footswitch will work with the Silvertone to turn the tremelo and reverb on and off. The reverb doesn't function on either one at the moment, but the trem does and sounds awesome! I'll have to come up with another footswitch I can add to my gigging equipment as I want to have one to use at home too. It's just a standard two button, stereo jack footswitch, lots of people make them.

This morning I ran my `74 Champ for a bit. It was acting up last week and I hadn't looked into why yet. It was acting up again this morning. Volume drops, sputtering, noise....I thought I'd try a new preamp tube since it still has the original. That didn't do anything....but while I was testing it, I heard some louder pops and cracks and noticed some faint wiffs of smoke coming from the input jacks! Holy SHIT!

I shut it down and pulled the chassis and took a look around. They place I bought it from had done some maintenance on it and in replacing the volume pot had done a shitty job soldering the lead to the input pin on V1. It looks like it's been variously shorting out and grounding out. I'll fix that next week and see if it corrects the problem. It had been working (and sounding) like a charm before this so I hope it's not too drastic. While in there I noticed it could use a retensioning of the tube sockets as well...

Here's a shot of the back of the Silvertone from the auction listing:

That's more like it.

I think it was three weeks ago now that I finished the `66 Corvette, but it may have just been two. I took a couple days to sand and polish the finish out. I started with 800 wet/dry and progressed through 1000, 1200, 1500 and finally 2000. I like using mineral spirits for the lubricant instead of water. Then I used my buffer with Maquires #1 & #2 polish it to a final shine. I'm very pleased with how this one came out, it has a great shine, the finish is quite thin and I have no sand throughs or significant flaws.

The pots and switch are new (CTS and Switchcraft), it's fitted with a treble bleed circuit and a TV Jones Powertron Plus. I kept the old guard and Grover tuners, but cut a new nut from bone. The bridge, of course, is the replacement Gotoh. It intonates perfectly, the frets feel great, and all in all it plays like a dream. Probably the best of all three of my `vettes.

About the only thing I may change is the pickup. I'm starting to really like the stock Gretsch Hi-Sens Filtertron in my Astro Jet. Much more so than the Powertrons in my other `vettes and the Powertron Plus in this one. The Filtertron doesn't have nearly as much of a humbucker character as these Powertrons do, and I find I prefer that. There is an edgey rudeness to the stock Filtertron and a lack of mids compared to the Powertrons that sound good in the mix with our band.

I think I'm going to experiment with some different pickups and may be switching all my Gretsches to what I find I like best. That could be a Hi-Sens Filtertron (essentially the factory stock Gretsch pickup), a Hot Rod Filtertron, a TV Jones Classic or a TV Jones Classic Plus. Those are my options, as I see things right now.

Click on the photo for the gallery of final pictures. No more refinishing projects this year as winter is almost here. I have a number of amp and pedal projects though, so I've got stuff to tinker with.

From 1966 Corvette finished