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Step 2Parts: What You'll Need
Parts
The guy who originally designed this amp, Poindexter of Audiotropic , has a wealth of information on his site about the parts he used. His device, called the Musical Machine, is made up of some very nice, but very expensive audiophile-type components (high quality specialty hookup wire, extra fancy solder). These components may well make for great sound, but somehow I just can't bring myself to spend $35 on a capacitor that I can have a reasonable facsimile of for two bucks, and my uneducated ears probably can't tell the difference anyway. So, for that reason, I have built the same circuit as Poindexter, but with cheaper and more available parts.
What You'll Need
The amp consists of two sections, the audio circuit and the power supply. Let's look at the parts in both.
Enclosure
You're going to need something to put your amp in, and there are definitely certain considerations to be taken when picking an enclosure. Transformers and especially the tubes themselves can get very hot, and so need to be in a well ventilated kind of area, preferably jutting out the top of the case. Unfortunately, in my case, I foolishly chose an enclosure purely for its looks, which ended up being a bit of headache. I picked an old wooden cutlery case, which just happened to have rather thick panels, making it painful to mount components that were designed to be mounted on circuit boards or thin metal project boxes. So, unless you want to spend the time making that kind of case work, I'd say go with something more conventional.
Transformers
What to Buy
You'll be making the audio circuit twice over since this is a stereo amp, after all, and so you'll need two output transformers. Poindexter uses very fancy special order transformers that are way out of my price range, so I settled for a Hammond 125D, which, as far as I can tell, works fine.
There are four transformers in the power supply, one for the heating filaments in the tubes (Hammond 166N6), one for the main positive supplies (Hammond 167G120), one for the negative supplies (an Amveco toroid), and a 'choke' transformer (Hammond 158Q). A choke isn't really a transformer but an inductor. Basically, the function of a choke is similar to that of a capacitor in parallel, it resists sudden changes in current, and so acts as a filter.
Where to Buy It
I got these transformers from Angela Instruments which has a ton of old high quality audio components. Another good place is Parts Connexion . The Amveco toroid I ordered from Digi-Key (part no. TE62045-ND).
Tubes
What to Buy
The tetrodes used in the main amplifier section are four Electro-Harmonix 6V6EH tubes, which are pretty easy to find. For the preamp tubes, we have two 5965 tubes which are double triodes, meaning each tube actually contains two triodes. If you look at the guts of the tube you will notice two separate metal sheaths; these are the triodes. Tube sockets are also essential for affixing the tubes to the case.
Where to Buy It
I got the tetrodes from [htttp://www.tubedepot.com Tube Depot] and the double triodes from Antique Electronic Supply . The sockets came from Antique Electronic Supply , eight-legged ones for the 6V6's and miniature nine-legged ones for the 5965's.
Resistors
What to Buy
For the most part I just used regular metal film resistors, although there are a couple of high-quality Kiwame's in there just because I had them. The 60K and 62.5 4W resistors that you see in the schematic, called the plate load resistors are actually each two 2W resistors in parallel, two 120K's for the 60K and a 120 and 130 for the 62.5K. A few nice resistors are pretty cheap and most people insist on using good ones for the plate load, but they aren't necessary everywhere. The 100 ohm resistors connected to the 6V6 screen are rated at a 1/2W and I didn't bother with anything special, just regular old resistors. Same goes for the 100K bias resistors, 1/2W, metal film.
Where to Buy It
You can get metal film resistors at various ratings at any electronic supply store in your neighbourhood, or you can order them online from a variety of suppliers like Digi-Key . For the fancy stuff try Parts Connexion , Angela Instruments , or Percy Audio . Of course, there are lots of other good suppliers, as Google will tell you.
Capacitors
What to Buy
The two 0.33uF capacitors in the circuit are meant cut off any DC coming through and allow only the AC audio signal to pass. While expensive capacitors would be nice here, I'm cheap and so I just used 630V Mylar capacitors (the ones that look like big red rectangles). Actually, the ones in my amp right now are 0.47uF, but that just means I'll get a little more bass. All the capacitors in the power supply are standard components, except for the few that I replaced with some orange drop-style caps that I had.
Where to Buy It
I just bought the 0.47uF filter caps from a local store, but if you want the shmancy ones, you'll have to try places like Angela Instruments . The power supply capacitors were all ordered from Digi-Key .
Diodes
What to Buy
I just used the UF1007 1000V 1A diodes recommended by Poindexter. Nothing expensive is really necessary I think, unless of course you choose to use tube diodes. Tube diodes will cost you extra and require a power supply for their heaters, though.
Where to Buy It
You can get them from Digi-Key or Parts Connexion and probably lots of other places.
Potentiometers, Switches, and Jacks
What to Buy
There are only three potentiometers in the amp, one for volume, and two for adjusting the bias on either channel. The one for volume is a double deck pot. There are two switches, one for the main power supplies and one for the tube heaters. Regular old single-pole double-throw switches are fine here. Since I only have one input in my amp, I don't have a DPDT to change between inputs like Poindexter. You'll also need two sets of speaker winding posts, so you have something to hook the speakers up to, as well as a set of stereo input jacks, and a plug for the power cord.
Where to Buy It
I personally didn't splurge on an expensive volume pot, but lots of people think it's an important part, so if you have the money feel free to splurge. Again, try Parts Connexion , Angela Instruments , or Percy Audio . For switches, posts, and jacks, try Radioshack or any other electronic supply store. The plug/fuse box for the power cord was from Digi-Key , and its part no. is Q201-ND. You will of course need a fuse for this, I think a 1A one, which you can get from any electronics supply store.
Other Stuff
You will need some screws, nuts, and bolts and those sorts of things, which you can get at any hardware store. As for hookup wire, Poindexter uses some pretty fancy stuff, but being the cheapo that I am I just used regular hookup wire form Radioshack.
The guy who originally designed this amp, Poindexter of Audiotropic , has a wealth of information on his site about the parts he used. His device, called the Musical Machine, is made up of some very nice, but very expensive audiophile-type components (high quality specialty hookup wire, extra fancy solder). These components may well make for great sound, but somehow I just can't bring myself to spend $35 on a capacitor that I can have a reasonable facsimile of for two bucks, and my uneducated ears probably can't tell the difference anyway. So, for that reason, I have built the same circuit as Poindexter, but with cheaper and more available parts.
What You'll Need
The amp consists of two sections, the audio circuit and the power supply. Let's look at the parts in both.
Enclosure
You're going to need something to put your amp in, and there are definitely certain considerations to be taken when picking an enclosure. Transformers and especially the tubes themselves can get very hot, and so need to be in a well ventilated kind of area, preferably jutting out the top of the case. Unfortunately, in my case, I foolishly chose an enclosure purely for its looks, which ended up being a bit of headache. I picked an old wooden cutlery case, which just happened to have rather thick panels, making it painful to mount components that were designed to be mounted on circuit boards or thin metal project boxes. So, unless you want to spend the time making that kind of case work, I'd say go with something more conventional.
Transformers
What to Buy
You'll be making the audio circuit twice over since this is a stereo amp, after all, and so you'll need two output transformers. Poindexter uses very fancy special order transformers that are way out of my price range, so I settled for a Hammond 125D, which, as far as I can tell, works fine.
There are four transformers in the power supply, one for the heating filaments in the tubes (Hammond 166N6), one for the main positive supplies (Hammond 167G120), one for the negative supplies (an Amveco toroid), and a 'choke' transformer (Hammond 158Q). A choke isn't really a transformer but an inductor. Basically, the function of a choke is similar to that of a capacitor in parallel, it resists sudden changes in current, and so acts as a filter.
Where to Buy It
I got these transformers from Angela Instruments which has a ton of old high quality audio components. Another good place is Parts Connexion . The Amveco toroid I ordered from Digi-Key (part no. TE62045-ND).
Tubes
What to Buy
The tetrodes used in the main amplifier section are four Electro-Harmonix 6V6EH tubes, which are pretty easy to find. For the preamp tubes, we have two 5965 tubes which are double triodes, meaning each tube actually contains two triodes. If you look at the guts of the tube you will notice two separate metal sheaths; these are the triodes. Tube sockets are also essential for affixing the tubes to the case.
Where to Buy It
I got the tetrodes from [htttp://www.tubedepot.com Tube Depot] and the double triodes from Antique Electronic Supply . The sockets came from Antique Electronic Supply , eight-legged ones for the 6V6's and miniature nine-legged ones for the 5965's.
Resistors
What to Buy
For the most part I just used regular metal film resistors, although there are a couple of high-quality Kiwame's in there just because I had them. The 60K and 62.5 4W resistors that you see in the schematic, called the plate load resistors are actually each two 2W resistors in parallel, two 120K's for the 60K and a 120 and 130 for the 62.5K. A few nice resistors are pretty cheap and most people insist on using good ones for the plate load, but they aren't necessary everywhere. The 100 ohm resistors connected to the 6V6 screen are rated at a 1/2W and I didn't bother with anything special, just regular old resistors. Same goes for the 100K bias resistors, 1/2W, metal film.
Where to Buy It
You can get metal film resistors at various ratings at any electronic supply store in your neighbourhood, or you can order them online from a variety of suppliers like Digi-Key . For the fancy stuff try Parts Connexion , Angela Instruments , or Percy Audio . Of course, there are lots of other good suppliers, as Google will tell you.
Capacitors
What to Buy
The two 0.33uF capacitors in the circuit are meant cut off any DC coming through and allow only the AC audio signal to pass. While expensive capacitors would be nice here, I'm cheap and so I just used 630V Mylar capacitors (the ones that look like big red rectangles). Actually, the ones in my amp right now are 0.47uF, but that just means I'll get a little more bass. All the capacitors in the power supply are standard components, except for the few that I replaced with some orange drop-style caps that I had.
Where to Buy It
I just bought the 0.47uF filter caps from a local store, but if you want the shmancy ones, you'll have to try places like Angela Instruments . The power supply capacitors were all ordered from Digi-Key .
Diodes
What to Buy
I just used the UF1007 1000V 1A diodes recommended by Poindexter. Nothing expensive is really necessary I think, unless of course you choose to use tube diodes. Tube diodes will cost you extra and require a power supply for their heaters, though.
Where to Buy It
You can get them from Digi-Key or Parts Connexion and probably lots of other places.
Potentiometers, Switches, and Jacks
What to Buy
There are only three potentiometers in the amp, one for volume, and two for adjusting the bias on either channel. The one for volume is a double deck pot. There are two switches, one for the main power supplies and one for the tube heaters. Regular old single-pole double-throw switches are fine here. Since I only have one input in my amp, I don't have a DPDT to change between inputs like Poindexter. You'll also need two sets of speaker winding posts, so you have something to hook the speakers up to, as well as a set of stereo input jacks, and a plug for the power cord.
Where to Buy It
I personally didn't splurge on an expensive volume pot, but lots of people think it's an important part, so if you have the money feel free to splurge. Again, try Parts Connexion , Angela Instruments , or Percy Audio . For switches, posts, and jacks, try Radioshack or any other electronic supply store. The plug/fuse box for the power cord was from Digi-Key , and its part no. is Q201-ND. You will of course need a fuse for this, I think a 1A one, which you can get from any electronics supply store.
Other Stuff
You will need some screws, nuts, and bolts and those sorts of things, which you can get at any hardware store. As for hookup wire, Poindexter uses some pretty fancy stuff, but being the cheapo that I am I just used regular hookup wire form Radioshack.
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thanks!
Don't know about the shipping.. How much did everything cost for the build?