[gibosi]

These tubes do very different things. The rectifier tube is part of the amp's electrical power supply. Its function is to convert the AC (alternating current) coming out of the wall to DC (direct current) which is used to run the amp. Many amps, such as the Feliks, use solid state rectifiers. The 6AS7 is a double triode amplifier used as an output tube. So again, these are very different tubes with very different functions.

 

[hypnos1]

Still awaiting further updates from the Feliks guys...I'm getting SO impatient!...but I must try to remember that creating a new product is no easy task (as I recall administrator Currawong pointing out in a thread somewhere...).
 
In the meantime, my combination of C3GSs and GEC 6AS7Gs in my modded Little Dot MKIV SE just keeps getting more and more magical...presumably because of further burn-in of the GECs (which were NOS...THANK GOD!...because now all 4 of my "ex-equipment" tubes - 2 of which were the coveted curved-bottom base version!! - are dead

...).
 
Soo...this means that the eagerly-awaited amp in question really is gonna have to go some to blow me away! Mind you, even if it only pips the LD by a margin, with less exotic/expensive tubes, then it will still be a marvel...no worries about pushing things to (or beyond!) the limit; having to use adapters; providing separate heater power supply, etc. etc. And as for when the GECs go in...I'm salivating already, lol!
 
The clock is still ticking...STOP IT, CJ..

...

 

[Lorspeaker]

u ever tried using a tube pre-amp b4 your tube amp? any comments?

 

[i luvmusic 2]

 I tried my MK III as pre amp for the CRACK it's nice but i'am a bit confused on which Volume control i have to use.I usually set the MK III volume all the way up and used the Crack volume to control the level.But some of the tube slight hum from the MK III is amplified. 

 

[Lorspeaker]

   I tried my MK III as pre amp for the CRACK it's nice but i'am a bit confused on which Volume control i have to use.I usually set the MK III volume all the way up and used the Crack volume to control the level.But some of the tube slight hum from the MK III is amplified. 

 
my own "logic" says the same to the above...
am using a CSP2+ as a preamp now, i read somewhere in the decwarethread..
to lower the vol on the preamp until the humm is silenced, then up the vol on the main amp to my listening level. that seems to work.
 
from what i am hearing...having a preamp stretches the soundstage deeper n adds more layerings
into those depth. ( at least with the csp2+ as preamp...not sure if thats the case with other preamps)

 

[gibosi]

When using a pre-amp and an amp with separate volume controls, it is my understanding that it is best to turn the volume all the way up on one of the units, which completely eliminates resistance in the signal path, and then control the level using the other unit. 
 
While not a tube amp, I use an Audio-gd Fun as a DAC/pre-amp in front of the LD. I turn the volume on the LD all the way up and control the level using the Audio-gd. Sounds good to me.

 

[Lorspeaker]

Not familiar with the best working range of tubes...
but i tot it is not good to listen to tubes at both ends of their volume ..
so i normally cut back a notch or two on either amps...just to feel safe.

 

[gibosi]

It is my understanding that when tubes are on, they are always running full tilt. If the volume control is set very low, the signal coming into the amp is attenuated, and therefore, you have a very small signal on the grid. And a very small signal on the grid results in a small signal out of the amp. If the volume control is set to the max, the signal coming into the amp is not attenuated at all, and therefore, you have a larger signal on the grid and a larger signal out of the amp. So the volume control has no effect on the tube itself. It only affects the size of the signal introduced into the tube for amplification.
 
Going back to using a preamp and an amp, both with volume controls, it is best to turn one all the way up to eliminate any resistance in the signal path. And use the other to adjust the level at the headphone jack. I use the analogy of a stereo system with a pre-amp and a power amp. Typically, the power amp has no volume control. Controlling the level is one of the functions of a pre-amp. So I crank the volume of my "power-amp", that is, the LD1+ my headphones are connected to, all the way up and I control the level with the Audio-gd. However, similar to ILM2 with his LDIII, I hear a little ground hum when it is maxed out, so I back it off a tiny bit, to eliminate the hum. My guess is there needs to be a minimal level of resistance in the volume circuit in order for it to operate properly.
 
My advice for ILM2 is to set the Crack to the maximum, as this is your "power amp", and control the level with your LDIII. If the Crack hums full on, just back it off a hair.
 
Anyway, this is only my opinion. It works for me. But of course, I know just enough about this stuff to get myself in trouble... but not enough to get myself out of trouble....  lol

 

[Lorspeaker]

i am enjoying this...i have a slightly diff self-imagined logic,
i turned the tube preamp to max, wanting to MILK out all the goodness of the tubejuice on the csp2+,
and controlling the full brunt of the tubegoodness at the final tubeamp...
opening up the volumetap on the headfone until my ears cant take in anymore..LOL
 
But logically..i think Gibosi is more correct.  
i will try it out. 

 

[MIKELAP]

  It is my understanding that when tubes are on, they are always running full tilt. If the volume control is set very low, the signal coming into the amp is attenuated, and therefore, you have a very small signal on the grid. And a very small signal on the grid results in a small signal out of the amp. If the volume control is set to the max, the signal coming into the amp is not attenuated at all, and therefore, you have a larger signal on the grid and a larger signal out of the amp. So the volume control has no effect on the tube itself. It only affects the size of the signal introduced into the tube for amplification.
 
Going back to using a preamp and an amp, both with volume controls, it is best to turn one all the way up to eliminate any resistance in the signal path. And use the other to adjust the level at the headphone jack. I use the analogy of a stereo system with a pre-amp and a power amp. Typically, the power amp has no volume control. Controlling the level is one of the functions of a pre-amp. So I crank the volume of my "power-amp", that is, the LD1+ my headphones are connected to, all the way up and I control the level with the Audio-gd. However, similar to ILM2 with his LDIII, I hear a little ground hum when it is maxed out, so I back it off a tiny bit, to eliminate the hum. My guess is there needs to be a minimal level of resistance in the volume circuit in order for it to operate properly.
 
My advice for ILM2 is to set the Crack to the maximum, as this is your "power amp", and control the level with your LDIII. If the Crack hums full on, just back it off a hair.
 
Anyway, this is only my opinion. It works for me. But of course, I know just enough about this stuff to get myself in trouble... but not enough to get myself out of trouble....  lol

With my Conductor's preamp i use my Pionner SX750 and HD800  i usually  set attenuator at 75% on preamp and ajust volume on Pioneer because i get hum at around halfway on Pioneer probably because of age and the high impedance of HP on lower impedance still hums but less,also loud is 9 o'clock on Pioneer

 

[Lorspeaker]

my preamp starts to hummmm at about  70% gain too...

 

[Rossliew]

I tried using the Little Dot Mk 3 OTL amp as pre-amp into the Mjolnir. At first i turned the MJ volume knob to the max output and used the LD's volume knob as control. With my HE500 and HD600, there was a noticeable hum on the left channel when no music was playing. Conversely, if I used the MJ as the volume control, there was no hum at all. But I noticed the sound coming out when using the LD as volume control was fuller bodied with punchier bass and more forward mids. In short, it sounded nicer to these ears but the hum was irritating. So, now I back off on the MJ volume knob to about 12 o'clock and still use the LD as control. Problem solved and it still sounds good!

 

[Lorspeaker]

did u find the soundstage improved? 

 

[Rossliew]

Hmm...i doubt if it did. I would believe adding a pre-amp into an integrated will just make it sound worse since you are adulterating the path which sounds travel (or something to that effect LOL). Oh well, it was just an experiment since the LD was lying around, not getitng any listening time..

 

[Lorspeaker]

The Csp2+ as a preamp...makes my DV336se sounds really huge.


But if I switch them around...they sounded worse off than being alone.