@ ckwong99
Yes because the Baby Huey amplifier use a special shunt feedback architecture with R13, which in combinaison of the feedback of the UL taps on the output tubes screen grid will be enough to get a stable amplifier without global feedback ! In fact this is an advantage of this amplifier because many Audiophiles didn't like global feedback
However if you build a pentode output version with the screen grid connected to a fixed regulated power supply, you may need to add the global feedback...
Marc
Yes because the Baby Huey amplifier use a special shunt feedback architecture with R13, which in combinaison of the feedback of the UL taps on the output tubes screen grid will be enough to get a stable amplifier without global feedback ! In fact this is an advantage of this amplifier because many Audiophiles didn't like global feedback
However if you build a pentode output version with the screen grid connected to a fixed regulated power supply, you may need to add the global feedback...
Marc
Well I do not know if it is progress or not. But today I placed an order with Mouser. Last week I drilled the top plate of my chassis for the transformers and cut the wood for the base.
As seems to be the way with these things I am waiting for parts from all over the freaking world.
I think I will be able to start the real building in the next few weeks.
I hope this helps
I will likely start a build thread as this one is way to big and diverse
As seems to be the way with these things I am waiting for parts from all over the freaking world.
I think I will be able to start the real building in the next few weeks.
I hope this helps
I will likely start a build thread as this one is way to big and diverse
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Hi
Looking for some recommendations on tube socket for the EL34 type
Looking for good quality stuff that makes good contact, I prefer the style can can be bolted to the chassis.
Are these good ?
6pc New 8pin Belton Style vacuum tube socket PCB mount valve For EL34 6550 KT88 | eBay
Also looking for some good one for the 12Ax7
Thanks
Eric
Looking for some recommendations on tube socket for the EL34 type
Looking for good quality stuff that makes good contact, I prefer the style can can be bolted to the chassis.
Are these good ?
6pc New 8pin Belton Style vacuum tube socket PCB mount valve For EL34 6550 KT88 | eBay
Also looking for some good one for the 12Ax7
Thanks
Eric
e_fortier,
If I were you, what I would do is use ceramic sockets for both the EL34 and the 12AX7, and run wires from the socket to the PCB, this will give you more freedom in terms of mounting. I don't know how this will play into the grid stopper resistor, however, as I normally see that mounted super close to the socket...
Personally, for my baby Huey, I am making many small PCB's for each section of the circuit, to give me greater freedom in mounting to the chassis.
If I were you, what I would do is use ceramic sockets for both the EL34 and the 12AX7, and run wires from the socket to the PCB, this will give you more freedom in terms of mounting. I don't know how this will play into the grid stopper resistor, however, as I normally see that mounted super close to the socket...
Personally, for my baby Huey, I am making many small PCB's for each section of the circuit, to give me greater freedom in mounting to the chassis.
Hi Eric,
Ceramic for the EL34. They tend to cook their base. A 6CA7 sounds better and doesn't tend to cook itself.
The 12AX7A should go into a socket with a shield. I wouldn't use ceramic, the normal sockets do just fine. If you can shock mount them the amp will be less subject to shock noise as you operate switches.
-Chris
Ceramic for the EL34. They tend to cook their base. A 6CA7 sounds better and doesn't tend to cook itself.
The 12AX7A should go into a socket with a shield. I wouldn't use ceramic, the normal sockets do just fine. If you can shock mount them the amp will be less subject to shock noise as you operate switches.
-Chris
Hi Eric,
For the KT88, ceramic makes even more sense.
One thing to keep in mind is the spacing between tubes and other tubes or objects. If I recall correctly, that would be 1/2 the diameter. That means 1 diameter between power tubes at a minimum. Having vents between tubes will also help. The KT88 does produce a lot of heat, so keep that in mind.
-Chris
For the KT88, ceramic makes even more sense.
One thing to keep in mind is the spacing between tubes and other tubes or objects. If I recall correctly, that would be 1/2 the diameter. That means 1 diameter between power tubes at a minimum. Having vents between tubes will also help. The KT88 does produce a lot of heat, so keep that in mind.
-Chris
Put the grid stopper where the tube is, not on the PCB. Solder the resistor on the socket, then connect this to the PCB using a wire. Install a jumper in place of the resistor on the PCB.
Has there been any discussion of fleshing this out to an integrated amplifier with line inputs?
I just got a set of PCBs from the last group buy and considering some ideas.
Any suggestions on a tube linestage that I could integrate as a “one box solution” with this design with minimal hacking?
I just got a set of PCBs from the last group buy and considering some ideas.
Any suggestions on a tube linestage that I could integrate as a “one box solution” with this design with minimal hacking?