Recorded a couple of clips of different genres. All but the Deep Purple clip are recorded on lead channel.
http://www.youtube.com/watch?v=s0oZdqoElg0
http://www.youtube.com/watch?v=Yr6v9VT5EQ8
http://www.youtube.com/watch?v=dsooRtjMdiU
http://www.youtube.com/watch?v=5dO1W8DJbDE
update. I finally finished the preamp and it's awesome. Still need to finish the figured maple shell but it doesn't stop me from using it :)
More info, schematic and clips here http://diy-fever.com/amps/mesa-mark-iic-pcb/
There's only one clip so far but I plan to add more soon.
I agree it's stupid to leave it exposed, but it's not stupid to have it since the chassis is already drilled because it will make it easier to swap tubes with other brands. I'd get it to someone to replace it with a locking pot that cannot be turned by mistake and make the wiring a bit tidier.
few factors:
* there's a local company that can make any tranny I want
* they cost a half or even third of what brand transformers cost (this one is less than 20$)
* I can't buy brand transformers here, so I have to order them from abroad which makes them even more expensive.
* there's a good...
Tnx!
I still haven't got the board but I got a report of a successful build from somebody else, so I figure it's ok to post.
Here's the board layout http://diy-fever.com/temp/iic+i_full.pdf
And toner transfer mask http://diy-fever.com/temp/iic+i_trace.pdf
Everything is in scale and correct...
Thanks guys! Tomorrow I'll order a PCB prototype for the two channel version. If it sounds as good as this perf board prototype I'll release the layout to public together with the BOM and other info. There are several people waiting for it to start their own builds.
Cheers,
Bane
Could be a bad contact, either solder joint or tube socket, or maybe a bad tube or cap.
Try tapping each tube while the amp is on with a pen or something to see it that changes something. If it's a bad contact around the socket you'll hear the change. Don't confuse it with microphonic tubes...
Recorded a clip today that shows some higher gain settings (80-90%)
http://www.youtube.com/watch?v=AmIzyH_9F-s
There are few mistakes here and there, but who cares :)
Cheers,
Bane
Thanks guys!
I'm working on a PCB which makes it easy for inexperienced builders to make it without much trouble. I'll post build plans and etch transfer when it's ready and tested. It will have both channels, for versatility.
Cheers
A) some mesa amps have the EQ circuit without the sliders, like contour control on the express amps.
B) those transistors cost less than 1$ retailed :) The most expensive part of the EQ are sliders and inductors. By eliminating sliders they cut the cost roughly to half.