New Trainwreck Inspired 2 channel amp

[Aurora]

1M resistors...?? The 1M's ground ref's included for the switches?

[UR12]

1M resistors...?? The 1M's ground ref's included for the switches?

No they are for the VVR. I add a .1uf cap between the tube grid and each vol control so the grids need a DC reference to ground. THis keeps dc grid leak from getting back to vol pot and making it scratchy when running the amp on lower voltages. I added the 1 meg resistors on the original from the tube socket pin to a ground lug mounted with one of the tube socket screws. I moved the resistors to the board where they can go to the normal preamp ground buss.

[UR12]

I finally got a clip of the Pegasus amp and thought I would post it here. Actually it's a whole song. I have been asked for a long time for clips so here ya go. This is the red amp on page 7 of this thread. This song is actually a work in progress and isn't in it's final version yet. I think the lead player is going back in the studio next Sunday to do some work on the lead part of the song and they are still tweeking and adding backup vocals but anyway it is what it is. At least you can hear him put the amp through it's paces. If anyone is interested, the band's name is Ten Carp Lie and my son is the drummer. You can check them out on the web on myspace.


The clip was revised and you can listen to it here

http://users.zoominternet.net/~jdhall/a ... culous.mp3

[MCK]

Dana, It sounds great! Wonderful to hear the amp in the band context too. Great job! And neat drumming by your son too I must say. This clip should make you proud on many fronts. Kudos.

[Structo]

Sounded great Dana!

Love that low end.

[M Fowler]

Dana, that sounded very good.

Complicated amp build, exactly

I have looked at your old posted info many times and said nope not attempting that one.

Mark

[da Geezer]

I've scanned thru all 8 pages & can't find the schematic.....is there one posted somewhere?

TIA, Geezer

[TheGimp]

Schematic is on page 4, 10th post down.

[mlp-mx6]

Arrangement suggestion (unsolicited). Cut the last note/chord, let it end on the iii-IV-iii-IV rather than resolving to the I chord..

Good sound, amp sounds great in the mix.

[ampdoc1]

Oh Yeah!! I like the guitar tone, the song and the band. Sounds as good as the best of the heavy genre on the radio. Sign 'em up!

DEH

[UR12]

MCK

Yea it is great to have my son kind of follow in my footsteps and I really enjoy going out to see these guys play live.

Thanks to everyone else for the comments. It has been a long time coming to finally get the amp into a studio setting and some nice clips.

MLP
I'll pass on the the recommendations and maybe try and post the final version when it's done. They take constructive critism very well and actually included a couple of other suggestions in one other song that they finished up back in Feb before he had this amp. They are hoping to have the CD finished by this spring but we will see how it goes.

[da Geezer]

Schematic is on page 4, 10th post down.

Thanks Gimp!

G

[mick]

Hi Dana, I was wondering if you could please give some more details about the mosfet switching you incorporated in the Pegasus amp, I was told about switching with mosfet's but I haven't been able to find any information about using them, I don't even know which mosfet's are used for this. If there is a thread here maybe someone could point me in the right direction, I've tried searches but found nothing, any help would be most welcome.

Thanks
Mick

[UR12]

Hi Dana, I was wondering if you could please give some more details about the mosfet switching you incorporated in the Pegasus amp, I was told about switching with mosfet's but I haven't been able to find any information about using them, I don't even know which mosfet's are used for this. If there is a thread here maybe someone could point me in the right direction, I've tried searches but found nothing, any help would be most welcome.

Thanks
Mick

Mick

I use a chip part number PS7141-2A . It has two opto isolated Mosfet switches in one 8pin dip. The come in either 400 or 600v and switch up to 150ma IIRC. Mark Huss turned me on to these some time ago. You can check out the datasheet here

http://www1.futureelectronics.com/doc/C ... A-E5-A.pdf

You could also use a descrete mosfet. I think Mojotone has some boards that you can buy to do this or I also sell the boards I use for switching in this particular amp. The only thing you need is a unused 5v tap or a small power tranny to supply 5vdc to my board.

[TheGimp]

Just be careful as they derate rapidly with temp (starting at 25°C). They are excellent for switching B+ to peramp stages, but you wouldn't want to try switching 150mA with them inside a amp chassis. You could parallel the two outputs with equalization resistors to increase the reliability/current capacity though.