Why i love 6550 tubes!

[JKMV12]

The simple reason: they are AWESOME! True story!

I just got a pair of Sovtek 6550's to replace the Sovtek 6L6's that the amp tech put in when he fixed my amp (which it still needs to go back for more work :x ). I used 6550's once before and then i switched to EL34's when they died. When my OT went out a couple months ago they must have took the EL34's with it. That is why i got the 6L6's. Both pairs of tubes were OK. I just replaced the 6L6's b/c i thought they were going microphonic (which i am 90% sure they were b/c the noise isn't as bad as before but it is still pretty noisy. i think it is due to the 1087...it is a noisy devil).

So why are 6550's so great? What i hear is more clarity and more punch/umph/power/energy[enter your preferred 'power' adjective here]. The bass notes are more crisp and defined and the midrange has a nice balance with the high end. As an example i always had the treble high and the mids b/t noon and 3 o'clock when using the 6L6's. For one thing the mids did not seem to be as strong as they do now with the 6550's. I couldn't find the right balance b/t mids and treble (and bass) to get the tone i wanted. The bass was always a little too muddy and the treble kinda dominated too much. Now with the 6550's i reversed positions of the treble and mids and now it sounds perfect (we'll see if that stays the same when i play it tomorrow...nothing is ever prefect).

So to recap:
1) Bass is crisp and defined
2) Plenty of clarity
3) UMPH and POWER
4) A more balanced midrange and treble (imo)
5) Pure AWESOMENESS

Any questions?

 

[rblyn]

Havent tried 6550's in my RM100's yet but that description sounds a lot like the KT88's I use, which seem to be like BIG EL34's...everything sounds better- bigger- clearer. Note definition is great, bass is clear and doesnt get flubby or loose sounding, mids have more PUNCH and the highs are never shrill sounding...just sings! Im thinking when it comes to tubes more glass=more balls!! :twisted:

 

[JKMV12]

Havent tried 6550's in my RM100's yet but that description sounds a lot like the KT88's I use, which seem to be like BIG EL34's...everything sounds better- bigger- clearer. Note definition is great, bass is clear and doesnt get flubby or loose sounding, mids have more PUNCH and the highs are never shrill sounding...just sings! Im thinking when it comes to tubes more glass=more balls!! :twisted:

i am pretty sure KT88's are the "KT" version of the 6550's. Just like KT66 are like 6L6's and KT77's are like EL34's. I've thought about trying KT88's as well and based on what you just said i think i will have to try them as well. Size DOES matter :lol:

Another thing about the 6550's is that the pinch harmonics sing with the same punch and clarity as every other note. When you play a pinch harmonic...it is actually a pinch harmonic 99% of the time. Not a weak little harmonic that wishes it could sound like Dimebag harmonics. No...6550 pinch harmonics are the real deal. :twisted:

I also have to give some credit to the MM OT i had installed a couple months ago (i killed the old one). I heard that a good test of transformer quality is how hot it gets when it is working. This one gets fairly warm but i think that is mostly do to the fact that there is a much hotter power tube and power transformer right next to it. The PT is obviously much hotter than the OT. I'm not sure what it really did to my tone but all i do know is it works great and it sounds great.

 

[Disciple]

I love 6550's, I also prefer 5881's as well. But if I'm using a combo in my rt250 it's either 6550 or 5881 and other is el34's.

 

[eyeball987]

I used 6550's at one point in time. All 4 and mixed with other tubes. I liked them well enough.

Then I went back to all 34's. That is just my sound. I need the crunchy mids.

I am using 6CA7's mixed with 34's as of yesterday and so far am pretty happy.

I still have a set of 6550's, 6L6's, and 34's sitting as back ups but I would use the 6550's last if it came down to it. Too each their own I guess.

I do have a 5751 in the PI for what it's worth. A 12AX7 in the PI seems to add something extra that I prefer to do without when using all 34's.

 

[JeffHenneman]

I like using 6550 tubes also. i currently have a set mixed with a set of EH 6l6. I feel that this combo lets the different preamp characteristics shine thru while keeping the 6l6 sound intact.

 

[BigBrewtus]

So what is everyone biasing their 6550s at?

 

[JeffHenneman]

If memory serves me correct the range is 35mv - 45mv. I usually bias tubes in the middle of the range and then adjust from there. So I have mine at 42mv.

 

[JKMV12]

So what is everyone biasing their 6550s at?

The number on the tube boxes said 47 so that is what i went with. Jeff is right...it should be 35-45mV. Maybe i should change it.

 

[JKMV12]

I used 6550's at one point in time. All 4 and mixed with other tubes. I liked them well enough.

Then I went back to all 34's. That is just my sound. I need the crunchy mids.

I am using 6CA7's mixed with 34's as of yesterday and so far am pretty happy.

I still have a set of 6550's, 6L6's, and 34's sitting as back ups but I would use the 6550's last if it came down to it. Too each their own I guess.

I do have a 5751 in the PI for what it's worth. A 12AX7 in the PI seems to add something extra that I prefer to do without when using all 34's.

ya i always have a 5751 in the PI. It cleans up some of the noise and imo add more clarity. It is basically the same as the 12AX7 with a lower gain factor. I don't think you really need that much more gain by the time you get to the PI. Its main job is to split the signal and invert one. I may go back to 6L6's or EL34's one day...they might fit better with a different module. Experience has told me that 6550's with the 1087 is a good combo. Plus the RM80 originally came with 6550's so maybe there is something to that.

 

[BigBrewtus]

Did anyone have to change their tube clips when using 6550s or any larger tubes?
Also would anyone be willing to trade me a pair of 6550s or KT88s for
a brand new pair of Electro-Harmonix 6CA7s? I bought a quad for my
RM100 but only have RM50s now.

 

[eyeball987]

Did anyone have to change their tube clips when using 6550s or any larger tubes?
Also would anyone be willing to trade me a pair of 6550s or KT88s for
a brand new pair of Electro-Harmonix 6CA7s? I bought a quad for my
RM100 but only have RM50s now.

I had to take out the tube clips when using 6550's.

I have a set of Tung Sol Cryoset 6550's (see link below) that I would trade. Not really a fair even trade but they are like new and I don't use them. Shoot me a PM and we can work out specifics.

http://www.cryoset.com/catalog/product_info.php?cPath=22_26&products_id=285&osCsid=95959caa4a8b377790b630da48277b10

I will post pics in a bit.

 

[eyeball987]