[Tomo]

Hey,

I wish I can show you the inside, Twofishy. It is different. I wired every parts point to point with a solding posts. No fancy pants circuit boards. Quite different experience from simply placing components on a ready build circuit board.

You know you can build a buffer with tubes? With the increasing availability of Russian tubes, there are very good low mu tubes perfect for such applications. I never tried out because I am lazy ... ok ok. I have to working nights and days on my PHD thesis!

Yep, I am gonna be Dr. Tomo!

Tomo

 

[twofishy]

I've seen tubes used as cathode followers, like so :

and also :

not sure if I wanna mess with such high voltages...

 

[rickcr42]

neither of those will drive a low impedance headphone without either adding a step down transformer which will give you negative gain or by adding a solid state device making the tube redundant since the solid state device can be used without the tube.

second is the parallel triodes thing.You need matched triodes in the same package-that is each section of the dual triode needs to be matched to the other-or the results will not be that good and why most prefer to go with either a hybrid VT/SS or Pentode/triode Mu Stage if you are determined to add a tube though my personal belief is it is far better to use the tubes in an actual line level preamp then leave the impedance conversion and drive to a true buffer that when not needed is just taken out with the flip of a switch leaving as little in the signal path as is needed to perform the job at hand

1-Gain stage to buffer
2-gain stage to power amp
3-stright buffer when gain is not needed and usually it isn't if your source is a CD player or sound card

 

[twofishy]

What about trying to use cathode followers, like this one :

(source: http://www.tubecad.com/october99/page4.html )

 

[twofishy]

Quote:

Originally Posted by Tomo /img/forum/go_quote.gif I wish I can show you the inside, Twofishy. It is different. I wired every parts point to point with a solding posts. No fancy pants circuit boards. Quite different experience from simply placing components on a ready build circuit board.

Is it this one?

 

[Tomo]

Yep,

That's my new amp. Pretty clean. The most expensive component is that golden resistors bolted to the chasis. They are very high quality high power iron clad resistors. I think I paid like 2000Yen (20 bucks) for a pair. It's quite funny if you consider the fact that mosfets costed me like less than a dollar for each.

Tomo

 

[twofishy]

Quote:

Originally Posted by Tomo /img/forum/go_quote.gif The most expensive component is that golden resistors bolted to the chasis. They are very high quality high power iron clad resistors. I think I paid like 2000Yen (20 bucks) for a pair. It's quite funny if you consider the fact that mosfets costed me like less than a dollar for each.

This reminds me of that "Pimp my Ride" show, where they replace old/crappy car parts with new and expensive stuff

 

[Tomo]

Sorry for really really late reply, twofishy.

You make me remember my happy day with Pimp-My-Ride TV shows. I LOVE THOSE. ...

I wish there are TV shows like ... PIMP-MY-AMP show. (I know there is a PIMP-MY-CAR-STEREO shows/events ... 160dB or something!!)

Tomo

 

[Freq Band]

(old thread revival)
"Buffer by itself"....
 
LH0033  buffer (can)
 
 
I have tried  using these by themselves, audio straight through, with no feedback loop. (or, no opamp in the loop).
The datasheet ideas aren't working for me.
I'm missing some basics in my understanding.
(I'm using very good PS bypassing, right next to the LH0033)
 
Problem:
Outside audio signal going straight through the LH0033 (in and out terminals) gives me extremely high offset, as if there is a design problem...(it's in the "volts" range).
Does this device require any sort of feedback loop " ??
 
Designs that DO work for me, are using an opamp, with the LH0033 buffer inside the feedback loop. That works perfectly !
I'm not understanding something basic here.
 
How can the LH0033 used in a design like "Aunt Corey's" preamp