Totally Tubular: The Tube Thread
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Jbraswell
Well-Known Member
Picking up these GE 6550 tubes to see how they sound in place of the KT120 in the Rogue.
The guy ran them in his Conrad Johnson amp and sold the amp sans tubes.
He was not entirely sure exact vintage. Thought was late 60’s early 70’s as these came out of an early 70’s Ampeg SVT amplifier.. the lettering is mostly worn off but the two that still have numbers appear are KY 88-5 on one and KY 18-5.
His test data:
Tested my TV 7/U tube tester
46,46,48,46 where 44 is good.
For me there is nothing wrong with the KT120 but since I am powering the LF woofers with the Denon amp, I thought I could maybe squeeze some more tubey magic out of the mids and highs. If it's not a more favorable sound, I can probably get my $200 back selling these.
The guy ran them in his Conrad Johnson amp and sold the amp sans tubes.
He was not entirely sure exact vintage. Thought was late 60’s early 70’s as these came out of an early 70’s Ampeg SVT amplifier.. the lettering is mostly worn off but the two that still have numbers appear are KY 88-5 on one and KY 18-5.
His test data:
Tested my TV 7/U tube tester
46,46,48,46 where 44 is good.
For me there is nothing wrong with the KT120 but since I am powering the LF woofers with the Denon amp, I thought I could maybe squeeze some more tubey magic out of the mids and highs. If it's not a more favorable sound, I can probably get my $200 back selling these.
Jbraswell
Well-Known Member
I bought these late '60s GE 6550A tubes and finally got them in today. Man they are sounding pretty good as I play the mono Let It Bleed.
I put the tubes in around 4 hours ago, biased them at 35 mA, and left the amp on for a good 4 hours.
The mids are bringing a bit more sweetness than before. Also cranked the mid attenuator to max on the JBLs after watching a video review from Erin last night. He said it takes a little bottom end out but smooths a drop in the mids in his test. @Mather you might try this on your JBL and see what you think.
Tube shot
I put the tubes in around 4 hours ago, biased them at 35 mA, and left the amp on for a good 4 hours.
The mids are bringing a bit more sweetness than before. Also cranked the mid attenuator to max on the JBLs after watching a video review from Erin last night. He said it takes a little bottom end out but smooths a drop in the mids in his test. @Mather you might try this on your JBL and see what you think.
Tube shot
Mather
Unknown Member
Tubes will do my head in, but damned if I don't LOVE the look of them. And I bet they sound great with the L100s. What's the wattage on that amp?I bought these late '60s GE 6550A tubes and finally got them in today. Man they are sounding pretty good as I play the mono Let It Bleed.
I put the tubes in around 4 hours ago, biased them at 35 mA, and left the amp on for a good 4 hours.
The mids are bringing a bit more sweetness than before. Also cranked the mid attenuator to max on the JBLs after watching a video review from Erin last night. He said it takes a little bottom end out but smooths a drop in the mids in his test. @Mather you might try this on your JBL and see what you think.
Tube shot
View attachment 219747
Jbraswell
Well-Known Member
Tubes are like having a cool car. No logic just chasing the fun and it is addictive.
The Rogue is 60w 4 ohms triode plus the Denon is pushing everything below 450 Hz with 160w 4 ohms.
Mather
Unknown Member
Very nice, the mids is interesting because there is definitely a drop but I already adjusted it with my room correction so I don't think it's necessary in my case but I might try it just for funzies...
Jbraswell
Well-Known Member
It definitely makes everything more linear here. Kind of need to recalibrate my ears after. Mainly with losing some fat bass.
Mather
Unknown Member
Yeah I mean I've got the sub and the speakers are crossed over at like 60 HZ so it shouldn't really affect that much on my end...
Jbraswell
Well-Known Member
mindhead1
Active Member
Wilsenton R8 Update
I just added the Horizon 6SL7 to my R8 and I have to say I’m impressed. I’ve had my R8 for about 3 years and rolled more tubes than I care to admit.
Current tube complement are the Psvane 4 x KT88-T MKII, 2 x CV181-T MKII, 1 x NOS Sylvania 6SN7 and the Horizon 6SL7s.
Prior to the Horizon 6SL7 I had Tung-Sols and rebased NOS Sylvania 6SL7s. These tubes are good, very dynamic compared to the stock tubes, but ultimately a little to hot in the treble for my liking so I always defaulted back to the stock 6SL7 for a less fatiguing listen. After reading the positive reviews of the Horizon tubes I decided to give them a go before selling the R8 and moving on.
The Horizon tubes are delivering a smooth and non-fatiguing top end with good dynamics and holographic soundstage. I think I’m good for a while and will not be selling the R8 anytime soon. When the time come to upgrade other tubes I'm definitely going to give the Horizon line a shot.
I just added the Horizon 6SL7 to my R8 and I have to say I’m impressed. I’ve had my R8 for about 3 years and rolled more tubes than I care to admit.
Current tube complement are the Psvane 4 x KT88-T MKII, 2 x CV181-T MKII, 1 x NOS Sylvania 6SN7 and the Horizon 6SL7s.
Prior to the Horizon 6SL7 I had Tung-Sols and rebased NOS Sylvania 6SL7s. These tubes are good, very dynamic compared to the stock tubes, but ultimately a little to hot in the treble for my liking so I always defaulted back to the stock 6SL7 for a less fatiguing listen. After reading the positive reviews of the Horizon tubes I decided to give them a go before selling the R8 and moving on.
The Horizon tubes are delivering a smooth and non-fatiguing top end with good dynamics and holographic soundstage. I think I’m good for a while and will not be selling the R8 anytime soon. When the time come to upgrade other tubes I'm definitely going to give the Horizon line a shot.
Jbraswell
Well-Known Member
Tube shots are needed for this type of post.
mindhead1
Active Member
Slimwhit33
Well-Known Member
What was this about by the way? Did I miss an update elsewhere?
Joe Mac
Well-Known Member
It’s not arrived yet. I bought a mono switch, a fancy SUT and the MM version this ear phono preamp. The mono switch and SUT arrived but these were on at least a month back order. Ordered it on 21/11 so hopefully it should be ready to dispatch early in the new year.
Slimwhit33
Well-Known Member
Looks forward to hearing your thoughts on that new chain! I’ve yet to dip my toes in the MC cart and SUT waters.It’s not arrived yet. I bought a mono switch, a fancy SUT and the MM version this ear phono preamp. The mono switch and SUT arrived but these were on at least a month back order. Ordered it on 21/11 so hopefully it should be ready to dispatch early in the new year.
Joe Mac
Well-Known Member
I’m really looking forward to hearing it, that stereophile review convinced me to get the MM one of this and pair it with a SUT. The Bobs one was just a bit steep once it had been shipped across the pond and import charges added. Got a great deal on a custom made SUT with Lundahl transformers from a company in Britain. Got some nice NOS 5751 tubes to run in it too.
Slimwhit33
Well-Known Member
That sounds awesome. Hope it arrives soon!
Slimwhit33
Well-Known Member
I’m “patiently” awaiting the arrival of the new toys today. Thinking I’ll only switch out the two middle 12au7’s with the Brimars initially and run everything else stock, then switch in the KT120’s once I move up to the open loft room. Best laid plans….
Slimwhit33
Well-Known Member
Big Betsy has arrived. Clearly I couldn’t help myself and threw in the KT120’s and all the Brimars. YOLO.
The KT120’s are enormous, but the cage does fit.
Had a scare initially when I got a bad tube indicator on start up. It was the front middle right position. Re-seated it to no effect. Then switched two of the 120’s and the same indicator came on. Shit.
I walked away and took a shower because the thought of shipping this thing back to Colorado made me break out in a sweat.
Came back and decided to throw an EL34 into just that one spot… no bad tube indicator. Hmmm. Replaced the EL34 with the KT120, no bad tube indicator. Gonna have to keep an eye on this, but for now she’s up and running.
Def prefer Ultra Linear over Triode so far.
Good stuff.
The KT120’s are enormous, but the cage does fit.
Had a scare initially when I got a bad tube indicator on start up. It was the front middle right position. Re-seated it to no effect. Then switched two of the 120’s and the same indicator came on. Shit.
I walked away and took a shower because the thought of shipping this thing back to Colorado made me break out in a sweat.
Came back and decided to throw an EL34 into just that one spot… no bad tube indicator. Hmmm. Replaced the EL34 with the KT120, no bad tube indicator. Gonna have to keep an eye on this, but for now she’s up and running.
Def prefer Ultra Linear over Triode so far.
Good stuff.
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