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 Post subject: Tube extenders
PostPosted: Wed Sep 12, 2018 6:16 pm 
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Joined: Mon Jan 25, 2016 7:19 am
Posts: 106
Location: Toronto, ON, CA
Hi all. I have a rogue cronus magnom. Rogue has confirmed the amp can handle kt120 and kt 88 no problem. However to do this they want me replace the entire chassis. I've recently learned "tube extendors that are plug and play exist. Cant find a lot on them though. Can anyone make a reccomendation. I don't need an adapter, just something that will raise the socket up about an inch.

Love to hear thoughts. Thanks.


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 Post subject: Re: Tube extenders
PostPosted: Wed Sep 12, 2018 6:35 pm 
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Joined: Thu Nov 25, 2004 6:45 pm
Posts: 190
Location: Dundas, ON, CA
Search for octal socket savers. Should provide about an inch of extension.


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 Post subject: Re: Tube extenders
PostPosted: Wed Sep 12, 2018 6:46 pm 
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Joined: Wed Mar 08, 2006 2:58 pm
Posts: 1192
Location: Ottawa, ON, CA
PcX have them, been meaning to buy a set myself, as I have the same issue with my Rogue Atlas.

http://www.partsconnexion.com/SOCKET-74489.html

-- 12 Sep 2018 21:54 --

Alternatively... I have an extra top-plate given to me by a friend who bought from Rogue the top plate that would accept the larger based tubes. Anyone have a suggestion as to how to 'make' the output tube holes about 2mm larger in diameter????


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 Post subject: Re: Tube extenders
PostPosted: Wed Sep 12, 2018 7:10 pm 
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Joined: Mon Jan 25, 2016 7:19 am
Posts: 106
Location: Toronto, ON, CA
alzmtbr wrote:
PcX have them, been meaning to buy a set myself, as I have the same issue with my Rogue Atlas.

http://www.partsconnexion.com/SOCKET-74489.html

-- 12 Sep 2018 21:54 --

Alternatively... I have an extra top-plate given to me by a friend who bought from Rogue the top plate that would accept the larger based tubes. Anyone have a suggestion as to how to 'make' the output tube holes about 2mm larger in diameter????


Fist, thanks. I'm buying those. Only other way is take it a machine shop and them widened. You could probably do it yourself with a good drill and the right attachment.


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PostPosted: Sat Sep 15, 2018 2:44 pm 
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Joined: Mon Jan 25, 2016 7:19 am
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Location: Toronto, ON, CA
Hey again. So, I received those parts and they are exactly what i needed. I ordered so KT-120s from the US. Does anyone know what the new tubes would bias to?


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 Post subject: Re: Tube extenders
PostPosted: Sat Sep 15, 2018 3:49 pm 
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Joined: Sun Dec 28, 2008 7:49 am
Posts: 1949
Location: Fairport Beach (in Pickering), ON, CA
JasonGR wrote:
Hi all. I have a rogue cronus magnom. Rogue has confirmed the amp can handle kt120 and kt 88 no problem. However to do this they want me replace the entire chassis. I've recently learned "tube extendors that are plug and play exist. Cant find a lot on them though. Can anyone make a reccomendation. I don't need an adapter, just something that will raise the socket up about an inch.

Love to hear thoughts. Thanks.


Glad you've got things sorted out, but just curious why the chassis would need replacing?

_________________
Tom

Collecting vintage tube Pilot (Pilotone) HiFi gear.


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 Post subject: Re: Tube extenders
PostPosted: Sat Sep 15, 2018 3:54 pm 
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Joined: Tue Sep 25, 2012 1:54 pm
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Location: Calgary, AB, CA
100% these:

http://www.tubemonger.com/Tubemonger_Ac ... s_s/78.htm


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 Post subject: Re: Tube extenders
PostPosted: Sat Sep 15, 2018 3:55 pm 
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Joined: Sat Dec 28, 2013 9:17 pm
Posts: 477
Location: Delta, BC, CA
Tom_r wrote:
JasonGR wrote:
Hi all. I have a rogue cronus magnom. Rogue has confirmed the amp can handle kt120 and kt 88 no problem. However to do this they want me replace the entire chassis. I've recently learned "tube extendors that are plug and play exist. Cant find a lot on them though. Can anyone make a reccomendation. I don't need an adapter, just something that will raise the socket up about an inch.

Love to hear thoughts. Thanks.


Glad you've got things sorted out, but just curious why the chassis would need replacing?

I'm going to take a shot in the dark and guess the tube sockets are below the top plate of the chassis, and further guess the kt120s are too wide at the base for the existing hole in the top.
It would be tricky to make the existing hole bigger and do it cleanly.


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PostPosted: Sat Sep 15, 2018 6:32 pm 
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Joined: Mon Mar 24, 2008 6:55 am
Posts: 392
Location: Toronto, ON, CA
JasonGR wrote:
Hey again. So, I received those parts and they are exactly what i needed. I ordered so KT-120s from the US. Does anyone know what the new tubes would bias to?


Hi Jason.
KT120 bias same as KT88 in the Rogues (I have a Stereo 90).
35ma on the meter. I assume you are using EL34 and are biasing at 30ma on the meter.
Not a big fan of the Tung Sol KT120 although they do produce a little more power. I recommend you try the Gold Lion KT66 next. Now that is a rocking tube in the Rogues! Bias those the same as EL34 (at 30ma).
Have you rolled the 12ax7 input tubes? Those make a BIG difference. You definitely want to go NOS in those spots.
Enjoy the roll!


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 Post subject: Re: Tube extenders
PostPosted: Sat Sep 15, 2018 6:38 pm 
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Joined: Mon Jan 25, 2016 7:19 am
Posts: 106
Location: Toronto, ON, CA
Bingo. Yes, this is the magnum v1 and designed for kt90. So the holes are about 2mm too tight, but otherwise the amp has no problem using the larger tubes.

Just trying to figure out whether the socket saver would cause any problems on their own (haven't read anything bad), and whether I need to bias them any different (don't think so).

Otherwise I'm hyped, heard a lot of good things.

Edit - hey Mendel, sorry missed your post. So see above. I have rolled all of the input tubes, although the JAN tubes it can with were great - better than most.

I have an amperex bugle boy with a treble clef for the preamp tube. It's from like 1960. It flashes, and it sounds amazing. Really notable. I've bought many others to experiment and most were worse in effect than the Phillips that it came with. The center tube is definitely where to roll with results. I did swap out the the 12ax7 with some gold lions. Not sure it did much. Could always revisit :)

Thanks for the bias info. I'm at 35 now, so I guess it will be the same.


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 Post subject: Re: Tube extenders
PostPosted: Wed Sep 19, 2018 4:14 pm 
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Joined: Mon Jan 25, 2016 7:19 am
Posts: 106
Location: Toronto, ON, CA
I just wanted to report back that this worked amazing and thanks again. These tubes are way bigger than I thought, about 1.5 the size of the kt-90. I had to alter a shelf to make them fit. Sound is different, does seem more open and detailed and the charachter is just a tad different. Really happy to have been able to do this without ordering the other top plate from rogue. For anyone swapping the new tubes were way too hot, so make sure to adjust the bias immediately. Cheers.


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 Post subject: Re: Tube extenders
PostPosted: Wed Sep 19, 2018 4:39 pm 
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Joined: Mon Mar 24, 2008 6:55 am
Posts: 392
Location: Toronto, ON, CA
JasonGR wrote:
I just wanted to report back that this worked amazing and thanks again. These tubes are way bigger than I thought, about 1.5 the size of the kt-90. I had to alter a shelf to make them fit. Sound is different, does seem more open and detailed and the charachter is just a tad different. Really happy to have been able to do this without ordering the other top plate from rogue. For anyone swapping the new tubes were way too hot, so make sure to adjust the bias immediately. Cheers.


Glad everything worked out!
Its a good idea to always turn the bias pots down before switching the amp on after an output tube change, then bring the bias up slowly for each tube. Bias to about 3/4 of the total for the new tube, play amp for about 30 minutes, then bring bias up to 100% for the tubes. Check bias again after a day or two to be sure it hasn’t drifted.
Learned this the hard way after losing a KT88 after a tube change when the bias for the previous tubes was too high for the new quad.
Enjoy the roll!


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 Post subject: Re: Tube extenders
PostPosted: Thu Sep 20, 2018 3:48 pm 
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Joined: Mon Jan 25, 2016 7:19 am
Posts: 106
Location: Toronto, ON, CA
MENDEL24 wrote:
JasonGR wrote:
I just wanted to report back that this worked amazing and thanks again. These tubes are way bigger than I thought, about 1.5 the size of the kt-90. I had to alter a shelf to make them fit. Sound is different, does seem more open and detailed and the charachter is just a tad different. Really happy to have been able to do this without ordering the other top plate from rogue. For anyone swapping the new tubes were way too hot, so make sure to adjust the bias immediately. Cheers.


Glad everything worked out!
Its a good idea to always turn the bias pots down before switching the amp on after an output tube change, then bring the bias up slowly for each tube. Bias to about 3/4 of the total for the new tube, play amp for about 30 minutes, then bring bias up to 100% for the tubes. Check bias again after a day or two to be sure it hasn’t drifted.
Learned this the hard way after losing a KT88 after a tube change when the bias for the previous tubes was too high for the new quad.
Enjoy the roll!


Eek. Good to know.....may be too late, lol.i have been rechecking though, seems to be staying put. Really happy with them.


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