#1
I'm going to be building another amp to correspond with my amp building resource thread.

Here's the specs:

Single-ended 6L6 (5w power)
(1) 12ax7
Gain, bass, mid, treble, and volume controls.

I will make the amp a point-to-point/eyelet board hybrid. I might add a switch to toggle between a dirtier and cleaner sound. This will be done by removing the bypass cap on the first triode of the 12ax7.

I will be recording sound clips, and then change a few parts to let you hear the difference small changes make.

I will be using the chassis and cab from my old "Matrix" brand practice amp that I intended to use for a different amp that was too complicated.

All parts are ordered and expeted to arrive by the end of the week. The amp should be finished by next week.

I will try to take many pics, but I'll need to borrow a friend's camera. Any questions will be answered or told to use google.
#2
Cool, I've been getting interested in amp designing and building. I'll probably end up building one of the ax84 kits whenever I manage to save up the money(which is hard when you're unemployed :rolleyes
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#3
I'm looking forward to this.
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#5
are you basing the circuit on anything existing?
and by the 'dirtier and cleaner sound' you're getting from the switch, how dirty/ clean are you talking?

I like how theres alot more amp-based threads lately I remember when there was barely any..
#6
I'm not too sure how dirty. It's not going to be up for metal. Probably plenty for hard rock though.

I'm not really basing off of anything in particular. It will be similar to an old Fender Blackface, but it will be hotter.

Parts came in just under $75. I already had some sockets and transformers.
#7
Dude, rock on!

If you put on one more preamp tube, there's a billion and one different ways you can take it. 1 12AX7 limits you pretty hard to somethign that sounds like a BF or an AX84 project.

...just a thought.
Quote by kcdakrt
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#8
Quote by DLrocket89
Dude, rock on!

If you put on one more preamp tube, there's a billion and one different ways you can take it. 1 12AX7 limits you pretty hard to somethign that sounds like a BF or an AX84 project.

...just a thought.



Definetly something I'll keep in mind, but don't forget, vintage Orange amps used 1 preamp tube. That's one of my favorite tones of all time especially the OR120.
#9
Quote by end_citizen
Definetly something I'll keep in mind, but don't forget, vintage Orange amps used 1 preamp tube. That's one of my favorite tones of all time especially the OR120.



True. *shrugs* I just like the versitility of having another tube to play with.

Are you designing this from scratch?

Another option to look at if you want more distortion "range" would be the LND150 MOSFET from Supertex. It subs almost directly for a 12AX7 and makes a great boost stage up front. Clean gains of over 250x voltage.
Quote by kcdakrt
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#10
Hello, all. I am back from the weekend. All the parts are here. It is a very straight forward build, but I've got some chassis work and homework I need to do before I can actually jump into the build.


Quote by DLrocket89


Are you designing this from scratch?

Another option to look at if you want more distortion "range" would be the LND150 MOSFET from Supertex. It subs almost directly for a 12AX7 and makes a great boost stage up front. Clean gains of over 250x voltage.



In a way I'm designing from scratch. It's going to be very basic for now. I plan on expanding this amp in the future. I might add another tube, but I don't know. If I like the sound I'll probably leave it as it is and just start voicing it.

Also, I've seen you mention that MOSFET boost several times. One day I will probably do something with one, but not for this one. Once I get a job I know the build I'm going to do, and I have several others I'd like to try.

Nothing like planning on where to throw your money
#11
I'm sorry for not taking pics, I was unable to get to a camera during buiding, but this amp is done-ish in its first stage.

I've still got to get rid of an annoying hum. Once that's out of the way I'll start recording and swapping parts.
#12
Everything is working. No more hum, and it all fits

I'll work on some sound clips for this first iteration of the amp. It is extremely LOW gain. I can crank it up and drive it with my Rockfield Mafia in the bridge of my guitar. I get a little bit of break-up. It would make a great jazz amp. I'll voice make it a little hotter by putting smaller value resistors on the cathodes of the preamp tube.

If that doesn't give it enough, I'll raise the value of the plate resistor on the second triode. I'll work on some pics, too.
#13
First iteration amp clips are up. Under "Amp Build v1.0"

First is a dirty sound with everthing cranked. I ran it through a Weber MASS attenuator to control the volume. I may have lost a little top end that way.

Then is the clean sound.

Both are using the mahogany telecaster I built. Both are using the bridge pickup which is very high output. It is a Rockfield Mafia.

The speaker is a Weber 8" AlNiCo Signature model. The mic is a Sennheiser e609. Software was Ableton Live 7.0. Converted from .wav to .mp3 with Switch Sound File Converter.
#14
nice

sound like something I'd really look for in a clean amp..
maybe with a bit more breakup, though, even for clean sounds. what were your settings on the second half of the clip?
#17
Originally I thought it had plenty of bass (especially for the small speaker). After changing some components for more gain, I'm with you.

I'm going to increase the value of a coupling cap and see if that helps.
#18
Second clips are up under "Amp build v2.0"

Changes made to circuit:

Lowered values of both cathode resistors from 1.5k to 1k.
Raised values of both plate resistors from 100k to 220k.

Recording setup is the same as above.

Next I will move the tonestack from between the two gain stages to after both gain stages. Also, I will increase the value of the coupling cap for more bass.
#19
Third clips are up "Amp build v3.0"

Changes made to circuit:
Moved tonestack after the second triode instead of between 1st and 2nd.

Tonestack stayd at this:
Bass 75%
Mid 60%
Treble 60%

First is the gain all the way up, volume on 2.
Then gain at 75%, volume on 2.
Last gain at 25%, volume on 5.


One last thing to do:
Change the coupling cap to increase bass response.