Amp DIY Project
Hey Folks
I'd been looking for ways to keep myself out of trouble and advance my musical endeavor. I thought I'd share my recent build-it-yourself experience. If any of you have ever thought of building your own amp, read on.
I've been thinking a lot lately about tube amps . I've been using classic tube amp models on my GNX3 almost exclusively, and a couple of my jam buddies have low-wattage tube amps that are fairly cool (one has a crate VC-508 and another has the little Vox AC4TV), so I figured it'd be a worthwhile project to build my own low-wattage tube amp. I'm not an electronics whiz but I can handle a soldering iron, so I was looking for something simple but usable: I wanted an amp I could use on jam night, I didn't want a toy.
There is a surprising variety of tube amp kits available. After a *lot* of surfing around reading about tube amp kits, listening to sound clips from a bunch of the kits, and talking to a couple of the folks who offer them, I settled on the 1/2 watt Gilmore Jr. kit from Rich at Guytronix.com. The Gilmore Jr. uses a single 12AX7 tube for the preamp and a single 6n1p tube for the power amp, and the design is super simple- the only controls are volume and treble-rolloff tone. Guytronix offers a beautiful looking combo cabinet as well, but I decided I'm going to tackle the cabinetry myself with the help of a furniture maker friend.
I ended up ordering the amp kit, plus a 12\" Weber \"Blue Dog\" speaker. While I was waiting for the kit to be delivered, I ran into an Eminence \"Lady Luck\" speaker on craigslist for $25, so I snagged that, too, figuring it would be fun to see how the amp sounds with different speakers.
The amp kit comes with virtually everything you need except the tools to build the amp, and I had those- soldering iron, wire cutters, strippers, multimeter, etc. Also included in the kit is a very thorough set of instructions, wiring and layout diagrams, schematic and parts list. The manual is pretty instructional in itself. I had done some background reading on the *very basic* principles of tube operation, and the manual's description of the amp's design was very clear and understandable.
I could *not* resist the urge to jump right in, and the first assembly step was pretty straightforward- mounting the transformers and tube sockets on the chassis- so I did that right away, but then reined myself in and made a point of reading (and re-reading) the instructions thoroughly before continuing. I've been super busy with work lately so it's taken weeks to find the time, but I've grabbed an hour here and three hours there. I'd say I've put a total of 11 hours into the assembly of the amp, all told.
The circuit assembly is based on a turret board, something I'd never heard of before. Basically it has posts that the wires and components get soldered to- very handy especially if you need to undo and redo any connections. Assembly consisted of: Mounting the chassis parts; soldering wires to the turret board that would eventually connect to the tube sockets and controls; soldering the capacitors, resistors and diodes to the turret board; connecting the power wiring to the plug, fuse holder, switches and ground; connecting the input jack to the preamp tube socket; connecting the tone and volume controls (probably the fussiest part); connecting the various wires to the tube sockets and finally connecting the input and output transformers.
Even a simple amp like this can seem daunting, but by reading and rereading the instructions and studying the wiring digrams before putting things together, it was for the most part fairly easy. Some components and wires have to be soldered while they're in their places in the chassis which required patience. There are only 5 components that get soldered to the turret board that have polarity, and I managed to put two of 'em in backward but caught it very early on in one of my myriad recheckings.
When the *first* moment of truth came (powering up with the tubes removed to check so-called B+ voltage) I thought I'd messed something up because the voltage was wrong, but I'd just forgotten how to use my meter! With B+ correct, I was ready to move on. I put the tubes in, connected the Lady Luck (figuring what the heck, if it blows up I'll ruin the $25 speaker), plugged in my ES-335 and powered up. It was stupidly exciting watching the 6n1p start to glow! Sadly the 12AX7 is shrouded so you can't see it... Anyway, after letting the tubes warm for a minute, i switched out of standby and oh my goodness! Not only did it work, but it sounded pretty durned nice, especially considering the speaker was just sitting there on the desk, no cabinet or anything.
One of the points behind a 1/2 watt amp is that you get to push the tubes without getting a visit from the police, or the ear-doctor. I put the amp volume at about 75%, put the ES on the neck pickup, tone rolled down to 3 and volume at 5-ish, and played a simple minor7 arpeggio. Nice and warm actually, a little bit of edge to it. Try a little pentatonic riff with a slide and some bending, a little harder pick attack, and the difference is really astounding. Turn up the guitar and wow, the edge is really coming out. Turned the amp up some more and crunched out some power chords- a little weak in the bottom but I think the cab will help there. I played for about 20 minutes and then put it back in standby to cool down. Whew. Since then I've had a chance to play with it some more, and put the Blue Dog on it (still no cabinet yet). The Blue Dog is *awesome* with this amp- it's warm and big sounding, amazing with so little power, and much more bottom to it. It also breaks up later, I'm not 100% sure why. Now I need to find the time to get the speaker cab built so I can really use it!
I'm also really looking forward to mic'ing it up and recording with it (I will post samples when I do).
So- if you're looking for a little technical fun, I highly recommend this kit. It wasn't exactly cheap but I think in the end it's going to prove to be a great value and get used a lot. It's already been fun and educational
Here are some links I've found helpful:
http://www.guytronix.com/
http://www.allenamps.com/index.php
http://www.mojotone.com/
http://www.marshamps.com/
https://taweber.powweb.com/store/kits.htm
http://ampwares.com/
http://www.18watt.com/
http://ax84.com/
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I'd been looking for ways to keep myself out of trouble and advance my musical endeavor. I thought I'd share my recent build-it-yourself experience. If any of you have ever thought of building your own amp, read on.
I've been thinking a lot lately about tube amps . I've been using classic tube amp models on my GNX3 almost exclusively, and a couple of my jam buddies have low-wattage tube amps that are fairly cool (one has a crate VC-508 and another has the little Vox AC4TV), so I figured it'd be a worthwhile project to build my own low-wattage tube amp. I'm not an electronics whiz but I can handle a soldering iron, so I was looking for something simple but usable: I wanted an amp I could use on jam night, I didn't want a toy.
There is a surprising variety of tube amp kits available. After a *lot* of surfing around reading about tube amp kits, listening to sound clips from a bunch of the kits, and talking to a couple of the folks who offer them, I settled on the 1/2 watt Gilmore Jr. kit from Rich at Guytronix.com. The Gilmore Jr. uses a single 12AX7 tube for the preamp and a single 6n1p tube for the power amp, and the design is super simple- the only controls are volume and treble-rolloff tone. Guytronix offers a beautiful looking combo cabinet as well, but I decided I'm going to tackle the cabinetry myself with the help of a furniture maker friend.
I ended up ordering the amp kit, plus a 12\" Weber \"Blue Dog\" speaker. While I was waiting for the kit to be delivered, I ran into an Eminence \"Lady Luck\" speaker on craigslist for $25, so I snagged that, too, figuring it would be fun to see how the amp sounds with different speakers.
The amp kit comes with virtually everything you need except the tools to build the amp, and I had those- soldering iron, wire cutters, strippers, multimeter, etc. Also included in the kit is a very thorough set of instructions, wiring and layout diagrams, schematic and parts list. The manual is pretty instructional in itself. I had done some background reading on the *very basic* principles of tube operation, and the manual's description of the amp's design was very clear and understandable.
I could *not* resist the urge to jump right in, and the first assembly step was pretty straightforward- mounting the transformers and tube sockets on the chassis- so I did that right away, but then reined myself in and made a point of reading (and re-reading) the instructions thoroughly before continuing. I've been super busy with work lately so it's taken weeks to find the time, but I've grabbed an hour here and three hours there. I'd say I've put a total of 11 hours into the assembly of the amp, all told.
The circuit assembly is based on a turret board, something I'd never heard of before. Basically it has posts that the wires and components get soldered to- very handy especially if you need to undo and redo any connections. Assembly consisted of: Mounting the chassis parts; soldering wires to the turret board that would eventually connect to the tube sockets and controls; soldering the capacitors, resistors and diodes to the turret board; connecting the power wiring to the plug, fuse holder, switches and ground; connecting the input jack to the preamp tube socket; connecting the tone and volume controls (probably the fussiest part); connecting the various wires to the tube sockets and finally connecting the input and output transformers.
Even a simple amp like this can seem daunting, but by reading and rereading the instructions and studying the wiring digrams before putting things together, it was for the most part fairly easy. Some components and wires have to be soldered while they're in their places in the chassis which required patience. There are only 5 components that get soldered to the turret board that have polarity, and I managed to put two of 'em in backward but caught it very early on in one of my myriad recheckings.
When the *first* moment of truth came (powering up with the tubes removed to check so-called B+ voltage) I thought I'd messed something up because the voltage was wrong, but I'd just forgotten how to use my meter! With B+ correct, I was ready to move on. I put the tubes in, connected the Lady Luck (figuring what the heck, if it blows up I'll ruin the $25 speaker), plugged in my ES-335 and powered up. It was stupidly exciting watching the 6n1p start to glow! Sadly the 12AX7 is shrouded so you can't see it... Anyway, after letting the tubes warm for a minute, i switched out of standby and oh my goodness! Not only did it work, but it sounded pretty durned nice, especially considering the speaker was just sitting there on the desk, no cabinet or anything.
One of the points behind a 1/2 watt amp is that you get to push the tubes without getting a visit from the police, or the ear-doctor. I put the amp volume at about 75%, put the ES on the neck pickup, tone rolled down to 3 and volume at 5-ish, and played a simple minor7 arpeggio. Nice and warm actually, a little bit of edge to it. Try a little pentatonic riff with a slide and some bending, a little harder pick attack, and the difference is really astounding. Turn up the guitar and wow, the edge is really coming out. Turned the amp up some more and crunched out some power chords- a little weak in the bottom but I think the cab will help there. I played for about 20 minutes and then put it back in standby to cool down. Whew. Since then I've had a chance to play with it some more, and put the Blue Dog on it (still no cabinet yet). The Blue Dog is *awesome* with this amp- it's warm and big sounding, amazing with so little power, and much more bottom to it. It also breaks up later, I'm not 100% sure why. Now I need to find the time to get the speaker cab built so I can really use it!
I'm also really looking forward to mic'ing it up and recording with it (I will post samples when I do).
So- if you're looking for a little technical fun, I highly recommend this kit. It wasn't exactly cheap but I think in the end it's going to prove to be a great value and get used a lot. It's already been fun and educational
Here are some links I've found helpful:
http://www.guytronix.com/
http://www.allenamps.com/index.php
http://www.mojotone.com/
http://www.marshamps.com/
https://taweber.powweb.com/store/kits.htm
http://ampwares.com/
http://www.18watt.com/
http://ax84.com/
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Comments
All told I spent less than $500 for the amp kit, speaker and shipping. I've put about 11-12 hours into assembly if you want to add labor cost, but I can't afford my own hourly rate
Regarding cost, yeah it's true that sometimes (frequently?) a DIY project adds up to more than you might have spent to buy the \"same\" thing already built. Here's how I looked at it- initially I thought the project was gonna be too costly, especially compared to buying one of the multitude of low-wattage tube amps and a matching cab. But as I looked at how the different amps are built I realized I was getting something more like a $900 '57 champ than a $200 champion 600 or Epi Valve Jr.
On top of that, I learned a bunch and kept myself out of other trouble for those 12 hours of assembly time. Just think how happy Shania would be if Shredd stopped ringing her phone for 12 hours!
-Rf.