Had a few requests for this...

 

In terms of a drilling template for the Megatron. I don't have CAD or anything, but this is the jpeg I did out for the drilling of my chassis. I'm not sure if it's useful to the rest of you but it's the closest I have. For the rest who have already built one, if you have something much more accurate, please share it.  

 

 

Thanks!

Finally finished casing the power supply. Next is the amp itself. I am still not sure how I am going to do it. Wood or metal.

 

Edited September 20, 201411 yr by eggil

Very nice PSU indeed. I like the external heat sink approach. Is that yellow thing a Neutrik powerCON?

Very nice Enrique.

Nicely done. It looks beautiful!

Very nice!

green amphenol military connectors. Definitely the right way to go.

 

very nice.

Yes, it is a powerCon, per Birgir's suggestion. External heatsink idea courtesy of Victor Chew and RiStar.
Thank you guys.

Edited September 20, 201411 yr by eggil

Your work looks great. I particularly  like the way you've handled the heatsinks and the chassis in general.

 

My only criticism is that you can still work on the wire dress a bit.  My projects always look like a mess at first pass. It usually takes me three revisions before I'm satisfied, and even then, there's always things you would change if you did the project a second time.  It helps to wait a few days before each revision.  Putting the project aside for a while clears your mind and gives you a fresh perspective.

Thanks Frank. You are right, wiring is still quite messy.

Edited September 21, 201411 yr by eggil

Have you checked temperatures in your PSU after prolonged use?

About 60 degrees Celsius

the sink or the devices?

60 degrees Celsius on the sink part where devices are attached to. The heatsinks themselves about 42 degrees at the fins.

hi guys. i have followed this thread for long and almost finished my megatron. But something bad happened. I have to pay for my dental payment and never have time to finish it. I have to sell my half-finshed megatron includes tubes. I posted the classified here: http://www.head-fi.org/t/738271/for-sale-el34-12au7-12ax7-and-transformers

updated the board layout for c1815/mpsw06

http://gilmore.chem.northwestern.edu/boards/megatron.zip

I have a few PCB sets available for this amp, US $75 plus shipping.  The boards were made by PCBnet in the US, 0.093" thick with 4 Oz copper.  The set is three PCBs (Megatron amp board, KGSSHV PSU board and one Stax jack PCB).  To be clear, this is not the latest Megatron that Kevin posted on Oct 22nd.  These were made two weeks before. 

the update on the board was for the mpsw06 transistors because the 2sc1815 are hard to get now.

otherwise no difference

Is it possible to use the e80cc in place of the 12au7? 

probably should work. double the filament current, so account for that.

Hello everyone

I read it several times and this trhead but there is some information that I did not understand (for my poor english).

EL34 pentode or triode configuration are?

There is autobias circuit for the el34?

What is the role of C1, C2, C6 anc C8?

Thanks at all and thank to kevin for his work!

triode mode

 

no autobias, if the tubes are reasonably well matched and the power supplys are correct

the most offset I have seen is about 5 volts

 

c1/c2 couple from the differential input stage to the second gain stage.

c6 and c8 do the same thing to drive the outputs

Thanks kevin,

I saw the board psu. there would be a real advantage to duplicate the part of +/- 450V?

The 6V volt filament is in AC?

There is many version of universal psu that have 300V out?

there is a version of the psu that has the output to 300V? the universal psu has a 'input to 75V AC and then you go to add to -450V, getting a -510V. you can not modifacare that to have the 300V output?

Sorry for the newbie queston!