[sbelyo]

Pics...

 

[jbloudg20]

Lookin really good! You are making me way too impatient to build mine

 

[sbelyo]

Thanks....

I'll take a picture of the finished guts tomorrow. It got a bit tight in the front with the xlr, 2 power caps, and 4 output caps. But it's all in there. It's got a little hum, but not too bad. I'll ground the heaters with 2 100 Ohm 2 watt resistors and see if that helps.

It's gonna need a cover, the 6AS7G gets hot enough that it may burn my little girl's fingers (she touches everything).

I'd say all tolled my cost was $225 with shipping from 4 different vendors and 1 set of tubes off of ebay. But you could easily trim $40 buy using the open frame style hammonds and getting all the resistors and caps from mouser. But you'll need at the very least a step drill that goes to one inch and a cordless drill.

 

[jbloudg20]

Quote:

Originally Posted by sbelyo Thanks.... I'll take a picture of the finished guts tomorrow. It got a bit tight in the front with the xlr, 2 power caps, and 4 output caps. But it's all in there. It's got a little hum, but not too bad. I'll ground the heaters with 2 100 Ohm 2 watt resistors and see if that helps. It's gonna need a cover, the 6AS7G gets hot enough that it may burn my little girl's fingers (she touches everything). I'd say all tolled my cost was $225 with shipping from 4 different vendors and 1 set of tubes off of ebay. But you could easily trim $40 buy using the open frame style hammonds and getting all the resistors and caps from mouser. But you'll need at the very least a step drill that goes to one inch and a cordless drill.

Wow did you buy a lot of boutique parts? Right now all I need is my power supply caps, chasis, and 2 transformers. Total cost for my balanced amp will be around $150.

I snagged a pair of 6AS7G's off ebay for $10 shipped. Not bad for two RCA's. I bought two new Electro-Harmonix 6SN7's, and I have all of the amplifier section's parts.

Unfortunately, it might be a while before I can actually begin construction.

 

[sbelyo]

Hmm.. Lets see.

Mouser $37.00 plus $7.00 shipping ($12.00 of this was panel mount XLR and switched IEC inlet)

AES $112 plus $10.00 shipping (Chassis, Bottom Plate, Xformers, Choke, Solen caps, Cloth cover wire, sockets, terminal strips)

Handmade Electronics $12.00 $7.00 Shipping (output caps, RCA's)

Home Depot $5.00 (screws, grommets etc)

Ebay $20.00 $8.00 shipping(NOS 6AS7G, and 6DJ8)

That would come to $218.00 Obviously you could trim $60.00 by getting the screws, output caps and grommets from mouser. Then switching to 1/4" input and just regular power cord. Also using the open frame variety of the Xformers and getting used tubes from AES.

I am using a seperate filament xformer because the 269AX doesn't have enough current to heat both tubes. I also collected the parts over time and didn't order all at once. I guess I did go fancy on the caps and transformers, but I was going for a certain look.

 

[sbelyo]

Hum is now gone.. Just put a 100 Ohm 3 watt resistor on heach heater pin to ground

 

[Rescue Toaster]

Quote:

Originally Posted by sbelyo Hum is now gone.. Just put a 100 Ohm 3 watt resistor on heach heater pin to ground

Did you ground the center tap? And still had hum?

 

[philodox]

I'll be watching this project closely. This amp bears a striking resemblance to one that I made which ultimately was a flop... though I think that this design is a bit more 'sane'.

 

[jbloudg20]

Quote:

Originally Posted by philodox I'll be watching this project closely. This amp bears a striking resemblance to one that I made which ultimately was a flop... though I think that this design is a bit more 'sane'.

I'll let you know how mine goes, as I am building mine balanced with a 6SN7 gain stage specifically to power my K340.

 

[philodox]

Sweet. I've got a friend who is building an Aikido [tubecad.com] and my plan is to wait until he is done so that I can have a listen. At that point I will decide between it and the bamaslama... and now this amp.

 

[sbelyo]

Quote:

Originally Posted by Rescue Toaster Did you ground the center tap? And still had hum?

Yeah... It wasn't really bad but it was annoying me.

Actually the heater supply on the 269AX does not have a CT so maybe that's where it was coming from. I used that supply for the 6DJ8.

This amp to me is sounding great. There is plenty of bass with my DT770's and the vocals are amazing. I noticed that the instruments sound more seperated.

 

[jbloudg20]

Quote:

Originally Posted by sbelyo Yeah... It wasn't really bad but it was annoying me. Actually the heater supply on the 269AX does not have a CT so maybe that's where it was coming from. I used that supply for the 6DJ8. This amp to me is sounding great. There is plenty of bass with my DT770's and the vocals are amazing. I noticed that the instruments sound more seperated.

I'll note the resistors to add to my heaters as well.

 

[sbelyo]

Quote:

Originally Posted by philodox Sweet. I've got a friend who is building an Aikido [tubecad.com] and my plan is to wait until he is done so that I can have a listen. At that point I will decide between it and the bamaslama... and now this amp.

This amp shows big promise. It's above anything I've built for around $200.00

I think the simplicity lends to it's nice sound. Once I do some tube rolling I'll try the PSU mods suggested above by Recue Toaster.

 

[sbelyo]

Quote:

Originally Posted by jbloudg20 I'll note the resistors to add to my heaters as well.

I tried the amp without it and there was a little hum. But now it's dead silent. I just took that trick from one of the other PSU designs floating around.

I just didn't feel like rectifying the heater voltage. I figured if all those designs from the 30's - 70's didn't have it I could at least try it.

 

[philodox]

Quote:

Originally Posted by sbelyo I think the simplicity lends to it's nice sound.

Trust me this is not always the case.

I'm glad it worked out for you though.