No, I never compared SRPP to the parallel 6sl7.
I tested SRPP just a little.... I didn't like it, but I only listened a short while.
Based on my VERY LIMITED testing and experience, I would say that just using 1/2 the tube was better than SRPP of the GC-CF I just tried.
Gets back to the KISS method!
But.... I ended up with something that sounds GREAT
6sl7 in parallel driven by a 3mA constant current source.
I did some back to back testing of the R loaded tube vs. the ccs
and, in spite if the fact a had to add one SS stuff, I LOVE THE SOUND WITH THE CCS
The normal R loaded 6sl7 had an output of 1V=39V,
with ccs, 1V=51V. And the distortion with the ccs is way lower!
So in my case, just over 1V will drive the 2A3 (-54V bias) with ccs,
compared to about 1.33V without the ccs.
Sheldon.... back the my first post. My problem with the GC-CF config
was that I didn't like the way the amp sounded when I listened to horn type instruments, saxaphone, trumpet ect.
(I really need to write better next time)
If anyone wants the details on the ccs, let me know or see
tubelab.com (10m45 chip)
Thanks to all that replied.
-Scott
I tested SRPP just a little.... I didn't like it, but I only listened a short while.
Based on my VERY LIMITED testing and experience, I would say that just using 1/2 the tube was better than SRPP of the GC-CF I just tried.
Gets back to the KISS method!
But.... I ended up with something that sounds GREAT
6sl7 in parallel driven by a 3mA constant current source.
I did some back to back testing of the R loaded tube vs. the ccs
and, in spite if the fact a had to add one SS stuff, I LOVE THE SOUND WITH THE CCS
The normal R loaded 6sl7 had an output of 1V=39V,
with ccs, 1V=51V. And the distortion with the ccs is way lower!
So in my case, just over 1V will drive the 2A3 (-54V bias) with ccs,
compared to about 1.33V without the ccs.
Sheldon.... back the my first post. My problem with the GC-CF config
was that I didn't like the way the amp sounded when I listened to horn type instruments, saxaphone, trumpet ect.
(I really need to write better next time)
If anyone wants the details on the ccs, let me know or see
tubelab.com (10m45 chip)
Thanks to all that replied.
-Scott
Scott, thanks for the info on the 6SL7. Did you use 2k2 or 1K for the resistors?
re: CCS- that chip was also used by pete millet with great results. i'm going to order a couple from DigiKey.
re: CCS- that chip was also used by pete millet with great results. i'm going to order a couple from DigiKey.
arnoldc said:
Arnold... if your asking what the cathode R is for the parallel / ccs:
Cathode R = 680R which at 30mA = about -2V
The ccs replaces the plate R, My ccs is set up like this:
330V B+ into A
1K Resistor from K to the plate(s)
4.7K Resistor from G to the plates(s)
I have seen some schema´s that have a cap between driver and the grid of the powertube,some doesnt have one.How do I know if it´s
safe to remove it,must be beter if there isn´t a cap,or isn´t it?
safe to remove it,must be beter if there isn´t a cap,or isn´t it?
I dont know how well css works without the cap.
I had the cap on from my normal (non-css) setup, so I just left it in there.
I had the cap on from my normal (non-css) setup, so I just left it in there.
sgerus, I'm so sorry i was not clear. i meant the resistors on the SRPP 🙁 I was wondering what makes some dislike the SRPP. What made you? About the sound.
ryssen, I'll make an assumption that those you saw without a capacitor are what is called "directly coupled" and comes in various flavors such as Loftin-White, Monkey, Free Lunch, etc.
ryssen, I'll make an assumption that those you saw without a capacitor are what is called "directly coupled" and comes in various flavors such as Loftin-White, Monkey, Free Lunch, etc.
Arnoldc,
When I was in srpp, I had 330v B+, two 2.2k, one for the bottom cathode to ground, the other between the top cathode and the bottom plate.
The heater ct was at around 87V
I gave this a very short listing test.... and didn't like it.
Sounded kind of dead.
But, dont rule out srpp based on my very limitted test.
Who knows, maybe it would sound better with 1K resistors?
One thing I will say,FOR ME, the parrallel config sounds better than the
grounded cathode-cathode follower or just using 1/2 the valve!
2 reasons to use the parrallel config over srpp, gc-cf:
1. you don't have to bias up the heater (I know, no big deal, 3 more parts)
2. Just using a single stage... with the output from the pate...
When I was in srpp, I had 330v B+, two 2.2k, one for the bottom cathode to ground, the other between the top cathode and the bottom plate.
The heater ct was at around 87V
I gave this a very short listing test.... and didn't like it.
Sounded kind of dead.
But, dont rule out srpp based on my very limitted test.
Who knows, maybe it would sound better with 1K resistors?
One thing I will say,FOR ME, the parrallel config sounds better than the
grounded cathode-cathode follower or just using 1/2 the valve!
2 reasons to use the parrallel config over srpp, gc-cf:
1. you don't have to bias up the heater (I know, no big deal, 3 more parts)
2. Just using a single stage... with the output from the pate...
I have a 6B4GSE amp with SRPP 6SL7 driver,when I read this trhead I got curious and connected the 6SL7 as ordinary single drivers,and the sound is less detailed less midrange,but the bass is the same.I tried
it with a 6SN7 but now the bass is almost bomy,wish I could have a switch between SRPP and single driver.Anyway I think I´m going back to SRPP.Wish I could try 6H30,6C45 or Ecc99.But that means metallwork
Is there any other octal triod I could try? 🙄
By the way,is there any benefit in driving the 6SL7 harder nearer its max ratings?
it with a 6SN7 but now the bass is almost bomy,wish I could have a switch between SRPP and single driver.Anyway I think I´m going back to SRPP.Wish I could try 6H30,6C45 or Ecc99.But that means metallwork
Is there any other octal triod I could try? 🙄By the way,is there any benefit in driving the 6SL7 harder nearer its max ratings?
I guess it's really a matter of preferences then. I like the 6SL7 SRPP for its detail and slam, I also liked the 6072 SRPP on Gordon Rankin's Bugle 45. But now I tend to use single-triode drivers, such as the 417A/5842 because I like their sound and they are high current drivers (relative to the 6SL7).
ryssen, try the 6SL7 SRPP with 1K resistors. It will give more "balls" to it 😀
ryssen, try the 6SL7 SRPP with 1K resistors. It will give more "balls" to it 😀
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