glip22 & leib10, Mo here...

[Ventura]

Gentlemen...

Alright, the TJ arrived today and I've been doing a lot of glass rolling in the preamp sockets. Life has been good. But the truth is? Those KT88s may to go and go SOON!!

Leib, you're running 6550s in a TJ - can these be drop in replacements for the KT88 or was that mod you had done on your TJ in order to compensate for these. To the best of my -medicated due to ankle surgery- knowledge, 6550s and KT88s are the same designation, only one was Brit made and the other US made.

glip, you're all about the Genalex KT77s - and yes - damn FINE glass in my 20thA. DAMN fine!! May even splash for 'em in my Hagen once I get that thing sorted out at the circuit level (another story altogether). So whaddup - you think the KT77s slay in the TJ as well? Now this leads me to believe that a mod would need to be done to compensate the bias as 77s are the same designation as 34s.

Tell me what's up men.

It's good to have a TJ in da hizzy again, but this one needs a little TLC. As for preamps - so far it's LPS in V1, TAD7025 V2 and V3, either an LPS in V4 or 5751 (jury's still out), V5 is inconsequential, and LPS or Ei in the V6 PI slot. These combos have been getting me near to ear. But the power bottles are preventing the final touch.

Peace,
Mo

 

[leib10]

You can drop in the 6550s, but be sure to only used Winged C. They're the only ones that can handle the high plate voltages. I would run them at about 32-33mA just to be safe. Tyler at TC tubes hooked me up with mine, which was one of the most nicely matched quad of tubes I've ever seen. Just mention that the plate voltage is about 525 and you should be good to go! The 6550s are going to give you a bit less bottom end, aggressive mids, and will cut back the glassy highs KT88s are known for. maddnotez on this forum really liked my Twin Jet with 6550s.

The KT77s are different, but you may like them. Bigger bottom end than the 6550s, a bit more EL34 in character with bouncy mids and smoother highs. The Gold Lions are excellent tubes. You WILL have to mod the resistor to get them or any EL34-type tube in there. I really didn't like EL34s in there- too compressed and a honky midrange with a lack of detail and note separation.

 

[Ventura]

Thanks Leib...

Save a resistor change at the onset, the 6550s are going in. And for the record, I'd only buy SED =C= 6550s

If this doesn't cut it, off we got to solder-land. I'm guessing that the bass is still there though - I mean, c'mon - the depth knob on that amp is like the red LAUNCH button at a vuke missile silo.

Correct me if I'm wrong

Peace,
Mojo

 

[leib10]

Oh yeah... it's definitely still there. Just crank the channel bass and depth and it's still got that striking massive yet tight low end.

 

[Ventura]

thetubestore.com has done well by me this last week

Matched quad with high rating to cope with the 530V PV has JUST been ordered.

Thanks for that rather quick, painless and easy-to-assist help

 

[tonedog]

thetubestore.com has done well by me this last week

Matched quad with high rating to cope with the 530V PV has JUST been ordered.

Thanks for that rather quick, painless and easy-to-assist help

I miss my TJ and rev. 2 .

Off topic but I broke my leg and ankle and had two long plates and 18 screws. Installed. This is my sixth week since surgery and man can I relate. Sucks.

Take care,

Steve Snider

 

[leib10]

thetubestore.com has done well by me this last week

Matched quad with high rating to cope with the 530V PV has JUST been ordered.

Thanks for that rather quick, painless and easy-to-assist help

No problem brother, you gotta let us hear some clips!

 

[ttosh]

I did the resistor snip on mine and agree with leib10, it sounded to compressed and honky. I went back to the KT88's and settled on the 6550's for my Twin Jet, sounded just right to me with those tubes. Awesome amp, get those tubes sorted out and crank her up so we can hear you hear in Oklahoma LOL.

 

[RSRD]

Off topic but I broke my leg and ankle and had two long plates and 18 screws. Installed. This is my sixth week since surgery and man can I relate. Sucks.

Take care,

Steve Snider

Get well soon Steve. Sorry to hear about the leg.

 

[Ventura]

I did the resistor snip on mine and agree with leib10, it sounded to compressed and honky. I went back to the KT88's and settled on the 6550's for my Twin Jet, sounded just right to me with those tubes. Awesome amp, get those tubes sorted out and crank her up so we can hear you hear in Oklahoma LOL.

Ya, I'm stoked. Crazy - I've had a lot of amps come and go over the years, but since selling the TJ, there's been something missing. Real nice to have her back in the house. Just needs a little tone/glass tweaking and we'll be thumpin' and pumpin' in no time.

I miss my TJ and rev. 2 .

Off topic but I broke my leg and ankle and had two long plates and 18 screws. Installed. This is my sixth week since surgery and man can I relate. Sucks.
Take care,
Steve Snider

Only amp I've ever "missed" Steve. Now, off topic but what the hell did you do to your leg and ankle? I'm in the same boat as you - 12 or 13 screws and a couple shafts holding my ankle back together. I'm still wandering around like a senile man going "like, WTF!?!?! I was walking... How the?!?!?! What the....!?!?! Seriously, WTF!?!?!?!?". Anyway - first hand front line in the trenches kudos and regards to you, m'man. I feel your pain!

Damn I love TwinJets

 

[tonedog]

Off topic but I broke my leg and ankle and had two long plates and 18 screws. Installed. This is my sixth week since surgery and man can I relate. Sucks.

Take care,

Steve Snider

Get well soon Steve. Sorry to hear about the leg.

Thanks!! I am miserable because all my amps are down in my basement and its brutal to get down there and worse to try and maneuver across the floor as there are pedals and cables everywhere. I bought a Vox battery powered 3 watt amp with built in effects and use the Bogner Red pedal to wank out with tolerable tone on the couch.

 

[tonedog]

I miss my TJ and rev. 2 .

Off topic but I broke my leg and ankle and had two long plates and 18 screws. Installed. This is my sixth week since surgery and man can I relate. Sucks.
Take care,
Steve Snider

Only amp I've ever "missed" Steve. Now, off topic but what the hell did you do to your leg and ankle? I'm in the same boat as you - 12 or 13 screws and a couple shafts holding my ankle back together. I'm still wandering around like a senile man going "like, WTF!?!?! I was walking... How the?!?!?! What the....!?!?! Seriously, WTF!?!?!?!?". Anyway - first hand front line in the trenches kudos and regards to you, m'man. I feel your pain!

Damn I love TwinJets [/quote]

Yes I will have another TJ no doubt. I like the way it roars and sings when cranked up through a regular Bogner 4X12. I prefer the all V30s or a mix of greenbacks and V30s.

My leg story is the freaking pussy of the year weak story but true:
New Years Eve sitting at dinner table after lots of good wine and a fine meal, wife screams from upstairs to "put the dogs away", I get up in my brand new socks I got for Xmas and slipped on the hardwood floor. Broke my leg in four places and my ankle joint cracked in 1/2. Doctor said if I was a horse they would shoot me and if I were diabetic they would amputate because I could not recover from the surgery.

As you know this is a fucking nightmare. I am hoping that the doc will let me start to put weight on it this week but who knows. I just do not want to have all this shit removed and have to go through another surgery.

Hope you recover well and hope that nobody else has to go through what Ventura and I are experiencing.

 

[Ventura]

My leg story is the freaking pussy of the year weak story but true:

As you know this is a fucking nightmare. I am hoping that the doc will let me start to put weight on it this week but who knows. I just do not want to have all this shit removed and have to go through another surgery.

Hope you recover well and hope that nobody else has to go through what Ventura and I are experiencing.

Mine's equally as shitty. Did it walking across a parking lot to get to the grocery store at 9am. Dude - I used to make money huckin' my ass off cliffs with skis on... Going downhill on a bicycle at stupid speeds over stupid terrain. This is Whistler, dude. And I get taken out by asphalt??!?!!? Ya, ridiculous.

Messes with the head - but hang in there... It does get better and in a couple weeks, months or whatever, it'll be history.

Mo

 

[tonedog]

My leg story is the freaking pussy of the year weak story but true:

As you know this is a fucking nightmare. I am hoping that the doc will let me start to put weight on it this week but who knows. I just do not want to have all this shit removed and have to go through another surgery.

Hope you recover well and hope that nobody else has to go through what Ventura and I are experiencing.

Mine's equally as shitty. Did it walking across a parking lot to get to the grocery store at 9am. Dude - I used to make money huckin' my ass off cliffs with skis on... Going downhill on a bicycle at stupid speeds over stupid terrain. This is Whistler, dude. And I get taken out by asphalt??!?!!? Ya, ridiculous.

Messes with the head - but hang in there... It does get better and in a couple weeks, months or whatever, it'll be history.

Mo

Thanks

 

[Ventura]

I did the resistor snip on mine and agree with leib10, it sounded to compressed and honky. I went back to the KT88's and settled on the 6550's for my Twin Jet, sounded just right to me with those tubes. Awesome amp, get those tubes sorted out and crank her up so we can hear you hear in Oklahoma LOL.

Hello Good Friend...
What did you end up biasing the 6550s at..??

Leib's recommendation is well heeded above, at a conservative 33mA or thereabouts. Maybe I'm out to lunch, but I'm thinking:
Plate Dissipation = 35W
60% to 70% output = 21W to 24.5W
PV = roughly 530V (I'll confirm with the Bias-Rite)
(21/530)x1000 = 39.6mA
(24.5/530)x1000 = 46mA

Thoughts?
Peace,
Mo

 

[leib10]

Just bear in mind that IIRC the max screen voltages for 6550s is 425 or 450 watts and the TJ's is well above that. I could be wrong on that though. Bogner recommends that you run KT88s at 38mA. I'd play it safe since the TJ was designed with a more robust tube in mind, at least at first to make sure your tubes can handle it.

 

[Ventura]

Just bear in mind that IIRC the max screen voltages for 6550s is 425 or 450 watts and the TJ's is well above that. I could be wrong on that though. Bogner recommends that you run KT88s at 38mA. I'd play it safe since the TJ was designed with a more robust tube in mind, at least at first to make sure your tubes can handle it.

Point taken! I've been under the presumption that 6550s can handle 600V PV...

Then again, I'm on aggressive pain medication

Thanks

 

[Ventura]

http://www.sedtubes.com/sed_6550c.html

DC Plate Voltage: 680V
Screen Voltage: 400V

We'll see how the biasing goes

 

[steve_k]

http://www.sedtubes.com/sed_6550c.html

DC Plate Voltage: 680V
Screen Voltage: 400V

We'll see how the biasing goes

Tell them to send you a quad with a high PC match, otherwise you may get out of the range of the bias pot. There are piggy backed bias resistors in it, courtesy of Bogner for the tweakers. Just clip the top one off and you are off to 6550 land. I couldn't get on with those 88's at all. SED's all the way for 6550's.

Steve

 

[Ventura]

Thanks Stevie...

Got a high-test quad of SEDs coming in the mail. Should be fine. I know the piggy back resistor you speak of - it's pretty obvious.

Rest of my preamp glass is arriving today - for both the TJ and the XTC (and a couple of Diezels etc).

It's nice to do this kinda thing in post-op recovery mode
Mojo

http://www.sedtubes.com/sed_6550c.html

DC Plate Voltage: 680V
Screen Voltage: 400V

We'll see how the biasing goes

Tell them to send you a quad with a high PC match, otherwise you may get out of the range of the bias pot. There are piggy backed bias resistors in it, courtesy of Bogner for the tweakers. Just clip the top one off and you are off to 6550 land. I couldn't get on with those 88's at all. SED's all the way for 6550's.

Steve