[luvdunhill]

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif Good question. I'm going to piggyback on. Is Gain, Gain? Is a gain of 5 on a B22 the same as a Gain of 5 on a EHHA?

yes... well, as long as you don't cause one to clip I suppose.

 

[johnwmclean]

Quote:

Originally Posted by MrMajestic2 /img/forum/go_quote.gif Those of you guys who are running balanced, what gain are you using?

I’m starting with 5.5 (total 11) balanced for my build, wiatrob was running this value with his balanced build.
I’m going to be socketing C2, C3, R13, R22 and R23 and have also included resistors between 2K and 1.5K for R13 for some experimenting.

 

[les_garten]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif I’m starting with 5.5 (total 11) balanced for my build, wiatrob was running this value with his balanced build. I’m going to be socketing C2, C3, R13, R22 and R23 and have also included resistors between 2K and 1.5K for R13 for some experimenting.

What do you use for a socket?

 

[MrMajestic2]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif I’m starting with 5.5 (total 11) balanced for my build, wiatrob was running this value with his balanced build. I’m going to be socketing C2, C3, R13, R22 and R23 and have also included resistors between 2K and 1.5K for R13 for some experimenting.

Great, sounds like a nice starting point. On another note, I was just about to order the Glassware PSU when I realized the shipping charge is almost the same as the board (ouch). Any chance I could modify a TREAD to work?

 

[sachu]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif I’m starting with 5.5 (total 11) balanced for my build, wiatrob was running this value with his balanced build. I’m going to be socketing C2, C3, R13, R22 and R23 and have also included resistors between 2K and 1.5K for R13 for some experimenting.

Sounds good...Can't wait to see all these new builds take off and get some face melting impressions going.

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif What do you use for a socket?

use this Les..

Quote:

Originally Posted by MrMajestic2 /img/forum/go_quote.gif Great, sounds like a nice starting point. On another note, I was just about to order the Glassware PSU when I realized the shipping charge is almost the same as the board (ouch). Any chance I could modify a TREAD to work?

I would rather suggest emplying a simple LDO voltage regulator (LD1085) for the job. You could build one for under 20$ capable of handing upto 5A in like 10 minutes.

 

[les_garten]

Quote:

Originally Posted by sachu /img/forum/go_quote.gif use this Les..

IC and Component sockets, that name makes sense!

Thanx!

 

[digger945]

Quote:

Originally Posted by les_garten /img/forum/go_quote.gif IC and Component sockets, that name makes sense! Thanx!

These are what I use. I hatch them out one at a time by cutting one edge of the plastic. Then I fill the hole on the pcb with solder, pick up the socket with sharp tweezers and hold it against the pre-soldered hole and heat with an iron on the other side until it slips through. Remove iron and hold straight the socket until it cools and your done.

One note to make, while your shopping for these pin sockets. Look at the data sheet and make sure it is big enough to take the lead of whatever your planning on socketing. Usually for me it's a resistor or small feedback cap.

 

[MrSlim]

I snagged a couple of these: Voltage Regulator Kit, AC/DC in, DC out, Based on LM317 - eBay (item 260479385900 end time Dec-18-09 05:57:25 PST) to make some Gamma2 power supplies, but was also thinking they would do fine as heater supplies for the EHHA, just add a small transformer, or even a Wallwart..

 

[johnwmclean]

SILLY IDEA DELETE

 

[johnwmclean]

Quote:

Originally Posted by sachu /img/forum/go_quote.gif Here you go...Tube B+ delay kit

sachu, what about this one:

Power Supply Delay Finish PCB for DIY Tube Amplifier - eBay (item 310182999079 end time Nov-28-09 18:26:05 PST)

so many options....

 

[sachu]

^^ yep..that would work great.

 

[MrMajestic2]

Quote:

Originally Posted by sachu /img/forum/go_quote.gif I am using this particular Peter Millet circuit for my heater supply that i put together on a perf board. Again, my heater circuit is capable of putting out 5A in regulated DC mode (8A in AC). So I can always scale my amp to balanced if I ever choose to by just adding two more amp boards.

Was looking through the posts and found this. Might actually do a board layout of this myself. Is the L1 common mode really needed and if so, what value?

 

[sachu]

Quote:

Originally Posted by MrMajestic2 /img/forum/go_quote.gif Was looking through the posts and found this. Might actually do a board layout of this myself. Is the L1 common mode really needed and if so, what value?

The inductor is basically for additional filtering. That supply was meant for filament supply for DHT tubes, but it works great for a heater supply as well.

I can sink upto 5A with that circuit and it has worked flawlessly in my EHHA with a pair of 6H30P-DRs.

Would cost you about 15$ to rig it up..if U can, dew eet i say.

 

[MrMajestic2]

Quote:

Originally Posted by sachu /img/forum/go_quote.gif The inductor is basically for additional filtering. That supply was meant for filament supply for DHT tubes, but it works great for a heater supply as well. I can sink upto 5A with that circuit and it has worked flawlessly in my EHHA with a pair of 6H30P-DRs. Would cost you about 15$ to rig it up..if U can, dew eet i say.

I weel dew eet

I will skip the choke, add a meaty heatsink and a 5A LDO.

 

[funch]

I have a quick question.
I just finished my EHHA. I can set the quiescent current to .22V with no
problem, but my bias voltages are around .1V low. I'm using a pair of
JAN Phillips 6922's. Should I be overly concerned with the low bias readings?