PowerAmp Pics

[Twisteramps]

Got most of my exterior parts in, so I drilled some holes and slapped this together. It's NOT wired at all... still waiting on more G10 to come in so I can cut it for the turret board, then install the turrets, mount internal components, etc.


Controls are power, standby, preamp volume, power amp volume,and power soak/post transformer volume, so you can get power tube saturation easily.

One thing I did on this was build in a tweedish preamp, so Fritz can plug into the front of the amp and he has a small Class A amp for recording with a power soak and a pre/post volume.

If he plugs into the back of the rack, it bypasses the preamp and works as a power amp only. This bypasses the preamp and the first gain stages. Power amp runs a single 6V6 and should put out around 3 watts. Believe it or not, that is loud enough through a good cabinet to require the power soak circuit... Fritz wanted something to get a good saturated tube tone at lower volumes. Here it is.

I love this stuff. [img]images/icons/smile.gif[/img]

Pete

[Genebaby]

Re: PowerAmp Pics

Nice again Pete, that would be a very handy little piece of kit.

Vic

[Infernal Death]

Re: PowerAmp Pics

Yes once again as always very nice work !
Just wondering how do you plan on doing the labeling ?
The easiest way i discovered is using those rubber letter (don't know if that's the right word). You buy them as sheets and use a pen to get them sticking on the surface you want. After that you need to spray clear coat over it to prevent the letters coming off from the panel (which can happen quite easy if there is no protection layer over them).
I use this method for all my diy project like this one:





Flo

[metafaza]

Re: PowerAmp Pics

Both of you guys do amazing things. May I ask about the cost of such a small amp? I'm looking for something like this myself and considering building one.

[Twisteramps]

Re: PowerAmp Pics

Well, it depends. If you're looking for one or two amps only, then you're going to spend a lot more money than it would cost to just buy them. I've been studying tube electronics for a few years, and have more than the cost of an amp in tools alone:

drill press for turret boards
hole saws for tube socket holes
a unibit for smaller holes
set of drill bits
soldering iron/desoldering tool
wire cutters/strippers
a GOOD digital multimeter
hand tools like screwdrivers, pliers
dremel for cutting and sanding on chassis
table saw

Then you have the cost of the parts. Depending on the quality of parts you use, you could spend a few hundred bucks and up, depending on the amp.

Then you have the reference materials... I have about $300 in books.

Then you add the time it takes to learn all this stuff.

Then you have what your time is worth... [img]images/icons/smile.gif[/img]

Your cheapest route would probably be to buy a kit with a predrilled chassis - you can get one for $200 and some change and up. That usually buys a really simple fender champ amp in a metal box, with no enclosure. You'd still need some tools and knowledge to build it, however.

If the entire goal is to have a cheap amp, buy a silverface fender champ for $150-$200. Or get a Peavey VTM 60 for $200-$300 if you want a higher gain single channel head.

Pete

[fritzreiser]

Re: PowerAmp Pics

Originally posted by Twisteramps:
Then you have the reference materials... I have about $300 in books.

<font size="2" face="Verdana, Helvetica, sans-serif">Hey Pete,

What is a good resource book to learn how tube amps work?

[Twisteramps]

Re: PowerAmp Pics

Originally posted by fritzreiser:
</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Twisteramps:
Then you have the reference materials... I have about $300 in books.

<font size="2" face="Verdana, Helvetica, sans-serif">Hey Pete,

What is a good resource book to learn how tube amps work? </font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">The Torres book (can't remember the name of it) - it's pretty good, but some of the stuff in it is really simplified. If you could only get one book, it would be the most complete/written for a guitarist type book.

There isn't a single good book. All of them have good and bad points. Some of the more interesting ones I have:

Aspen Pittman's Tube Amp Book. I have an older version - a lot of it is a huge Groove Tube ad (Aspen owns GT). Interesting articles and stuff... a good read.

The two Gerald Weber books. These have some general overviews, and are really slanted towards Fender circuits. Good stuff, but a lot of "Gerald Weber is the coolest guy in the world" type stuff.

I have several of Kevin O'Connor's books (the London Power guy). They are full of information, but written at a fairly high technical level. These are good to check out after you've digested some of the books above. He spends 90 pages in one of the books just talking about channel switching. Then another 50 or so pages about fx loops, etc. His amps are insanely pricey too... His 50 to 0 watt 'studio' power amp is $2800 or so.

And they aren't guitar amp related, but I have some old electronics textbooks from the 50s and early 60s that are KILLER for the basics. They also have some pretty different approaches to tube electronics than most of the guitar amp stuff - most of what you see in guitar amps is derived from Fender or Marshall. It's interesting to see different ways of doing things.

Pete

[BigDaddyD]

Re: PowerAmp Pics

nice

[Twisteramps]

Re: PowerAmp Pics

Thanks guys. Flo - I'm going to be screen printing my faceplates in house on the amps and power amps. To keep costs down and the entire thing a one man show, I pretty much do everything but build the transformers. : )

Pete

[metafaza]

Re: PowerAmp Pics

All I want is a low wattage amp so my better half wouldn't kick me out of the house. I got stubborn in the sense that I want it to be all tube. I found one here in Poland it's a 5W combo, two preamp tubes, tube rectifier and one power tube. Just under $200. I think it's a good price compared to what I'd have to pay for it in the US. The problem is I'm a bit tight on money right now, so I guess it has to wait. I will definetly learn some things about tube amps, at least enough to service my little amp in the future.