Post by alseic on Dec 27, 2014 14:48:33 GMT -5
Hi
Do you know what is the safe mA range for tubes in Splawn Competition KT77 (it came out with JJ KT77 from factory) ?
I've measured both tubes with some meter (it seems to be good, tested it on other amps and compared to tube rating), it seems that one tube has 20ma, the other one has 15mA.
Unfortunately I don't know what's the plate voltage and I don't want to mess with high voltages to check myself.
It seems that bias is set low in that amp - I've got multiple tube sets rated by some shop, rating is similar to measurements using my Landry amp.
In Splawn all meaurements seem to have substraced 11mA.
For example if tube has a rating 36mA, in Landry it has ~34, in Splawn ~25 etc.
So I guess that stock tubes have average 28mA rating (shop "rating"), when I put same tubes with higher rating - 36mA - i get more blue glow (look at the attachements).
As you can see on some angles it's not that visible (also it's not as bright as camera shows on one of the pictures.
I just wonder if it is ok to run tubes with so low mA in this amp.
I really like its sound with these particular tubes and that bias, using same tubes with 8mA more doesn't sound as good to me (it lacks fullness, low mids) (maybe new KT77 sound different, I don't know)
I've asked Splawn via e-mail and facebook, no luck, like in the past, so I'm asking here, maybe somebody will know. I saw some discussions on this board but I wonder if KT77 model was different.
BTW. I tested JJ E34L, EL34, 6CA7, KT77, EHX EL34, Ruby EL34 BHT, Ruby STR - if you are looking for "simpler", metal sound I'd suggest trying KT77 and 6CA7 (it feels more solid, not so vintage).
6ca7 is tighter/rounder/more classic (not much gain), KT77 slays.
Unfortunately KT77 lows are big, but not super tight, highs can be unpleasant, so I used Sovtek WB (tightens low and adds high-mid cut)- Tungsol (nice full mids) - China 12ax7B (tight, mid cut) - probably low gain (there are at least 5 types Shuguang/China tubes, also their sound is not as consistent as in other tubes from my experience...) and it slays.
Attachements:
1st - 36mA KT77 / measured 24, blue glow could be easily seen above logo
2nd - 36mA KT77, different angle
3rd - probably 28ma KT77, measured ~ 18 (20 and 15), no blue glow was visible by eye
Do you know what is the safe mA range for tubes in Splawn Competition KT77 (it came out with JJ KT77 from factory) ?
I've measured both tubes with some meter (it seems to be good, tested it on other amps and compared to tube rating), it seems that one tube has 20ma, the other one has 15mA.
Unfortunately I don't know what's the plate voltage and I don't want to mess with high voltages to check myself.
It seems that bias is set low in that amp - I've got multiple tube sets rated by some shop, rating is similar to measurements using my Landry amp.
In Splawn all meaurements seem to have substraced 11mA.
For example if tube has a rating 36mA, in Landry it has ~34, in Splawn ~25 etc.
So I guess that stock tubes have average 28mA rating (shop "rating"), when I put same tubes with higher rating - 36mA - i get more blue glow (look at the attachements).
As you can see on some angles it's not that visible (also it's not as bright as camera shows on one of the pictures.
I just wonder if it is ok to run tubes with so low mA in this amp.
I really like its sound with these particular tubes and that bias, using same tubes with 8mA more doesn't sound as good to me (it lacks fullness, low mids) (maybe new KT77 sound different, I don't know)
I've asked Splawn via e-mail and facebook, no luck, like in the past, so I'm asking here, maybe somebody will know. I saw some discussions on this board but I wonder if KT77 model was different.
BTW. I tested JJ E34L, EL34, 6CA7, KT77, EHX EL34, Ruby EL34 BHT, Ruby STR - if you are looking for "simpler", metal sound I'd suggest trying KT77 and 6CA7 (it feels more solid, not so vintage).
6ca7 is tighter/rounder/more classic (not much gain), KT77 slays.
Unfortunately KT77 lows are big, but not super tight, highs can be unpleasant, so I used Sovtek WB (tightens low and adds high-mid cut)- Tungsol (nice full mids) - China 12ax7B (tight, mid cut) - probably low gain (there are at least 5 types Shuguang/China tubes, also their sound is not as consistent as in other tubes from my experience...) and it slays.
Attachements:
1st - 36mA KT77 / measured 24, blue glow could be easily seen above logo
2nd - 36mA KT77, different angle
3rd - probably 28ma KT77, measured ~ 18 (20 and 15), no blue glow was visible by eye
Attachments:
