Buffing a Rogue Stereo 90

[stringdriventhing]

Mornin' All - I'm a "virgin" here at Audio Nervosa, so please treat me gently. I'm up to my bloody eyeballs in a major system overhaul - from stem to stern. I snagged a two-year old, one owner, Rogue Stereo 90 off of Audiogon and it should be arriving on Monday of this coming week. I'd be interested in knowing if there are any members who have had any experience with the "Super Magnum" upgrades for this amp, and whether they represent a decent "value" in what they offer sonically. I'll be looking to upgrade whatever I'm able to afford as time goes along. I've already contacted Rachel at Grant Fidelity and had some discussion about the Shuguang Treasure KT-88's as well as smaller signal tubes and will likely pull the trigger on this upgrade first - it'll be a bit of a shame to hide such gorgeous looking tubes "under the hood" of the Rogue. Any suggestions on mods that actually get results will be greatly appreciated, and probably implemented. Thanks for lettin' me hang - String

[richidoo]

Hey String, welcome to our little corner of the web.

Rogue Stereo 90:

http://www.rogueaudio.com/Products_90.htm

There are other 6SN7 variants now that keep up with the Treasures. The Treasure CV181 has lower max plate voltage rating than 6sn7, so check with rogue that it is OK. I think the rating is 300V, which is higher than most tube amps use on signal tubes.

I would recommend JPS Superconductor 3 speaker cables to maximize your bass response and tonal clarity with any tube amp because they are sensitive to load impedance. Speaker cables raise the impedance and the bass clarity suffers.

Where do you live?
Rich

[stringdriventhing]

Rich - thanks for welcoming me to the fold. I'm not purposely being secretive, I just haven't scoped out all the variables available in setting up my profile - so I'll say it loud, I'll say it proud, I'm living in the San Francisco Eastbay area. Alameda is a little island community separated from Oakland and my Warriors/A's by an estuary. A very cool, smallish town.

Thanks for your suggestions regarding tubes. As it stands I've exchanged emails with Mark Obrien and after sending him the specs for the the Treasure CV-181Z he seems to think they should be fine in the Stereo 90. If you or anyone else has tried and true alternatives I'll wanna hear all about it. I'm home recovering from a couple of major surgeries and until I get myself back to earning, I've GOT to make my moves count with what is a miserly budget. I'm standing pat with some Grover Huffman speaker cables until I can afford to move on dialing in the cabling but I'm really grateful for the cabling tip. I've never owned such high efficiency speakers and I'm gonna have to be careful of the learning curve. - String

[richidoo]

I've lived on a few islands. Sometimes nice, sometimes not so nice. Glad you're on a nice one...

Some 6SN7 Variants to consider:
Synergy HiFi/Create Audio
Black Treasure CV-181
Electro Harmonix ain't bad if you're on a budget, most local music shops carry it, or partsexpress.

6sn7 Opinions:
http://www.audiocircle.com/index.php?topic=79732.msg
http://www.enjoythemusic.com/magazine/equipment/0304/6sn7.htm
http://www.dehavillandhifi.com/6sn7_vt.htm

Let us know what tubes it comes with, they might be keepers, or at least fine to start while you get used to the amp. The previous owner's experience is valuable, so if it doesn't come with upgrade tubes, ask him what tubes he liked in it - sellers sometimes don't include their best tubes in a sale. If they are they power original tubes they may be past their prime. A set of EH power tubes is cheap and handy to have as backup. Good idea to have some spare tubes and fuses on hand and learn to bias the amp yourself.

[stringdriventhing]

Rich - I fully expect the amp to arrive on Monday chock full of EH tubes. The seller claims he has just recently re-tubed with KT-90's and I'm pretty sure that EH is the main and maybe only outfit currently producing that tube. I was a guitar player in a previous life and was never particularly impressed with the EH stuff I sampled in my rig. But that was THEN, and there certainly seems to be a greater wealth of options these days. I'm hoping the Shuguang KT-88's will prove to be the real deal when I'm able to go for them. It'd be a relief to have a constant and reliable source of tubes without having to rely on NOS sources. -String   

[richidoo]

I'm hoping the Shuguang KT-88's will prove to be the real deal when I'm able to go for them. It'd be a relief to have a constant and reliable source of tubes without having to rely on NOS sources. -String   

I feel the same way. I wouldn't buy a tube amp that couldn't take Shuguang premium tubes, treasure or pssvane.  But their popularity has inspired competitors to make high end tubes. Everyone who has sampled the Treasures has reported a positive experience.

[tmazz]

I'm living in the San Francisco Eastbay area. Alameda is a little island community separated from Oakland and my Warriors/A's by an estuary. A very cool, smallish town.

Welcome aboard String. 

Did your area take any damage from the remnants of the Japanese earthquake this week?

[Bunky]

Hey String,The Black Treasure CV181-Z is the best 6SN7 variant i have tried including several very expensive vintage tubes this includes both running them in the preamplifier and as input and driver tubes of a power amplifier. the only Black Treasure power tubes i have tried are the KT66-Z and i prefer the Genelex reissue KT66 over the treasure KT66-Z. alot of times i prefer a Winged C 6550 over a KT-88 in amps that use either tube but my all time favorite tube in these kinds of amps were the type II Ei KT90's. just ask Jim McShane how good these power tubes could sound  if money is tight and you want to try the Treasure KT88-Z or CV181-Z i know where you can get a matched pair of CV181-Z for $124.00 shipped and a matched Quad of KT88-Z can be had for $254.00 shipped  i dont buy tubes from the North American distributor of Black Treasures because i percieve them as treating these tubes as a rare and hard to obtain commodity and then pricing them accordingly. they are not rare or hard to obtain and the fact is that the largest tube manufacturer on the planet is manufacturing them every day in China.GOT TUBES? HELL YEAH!    i love a free market economy they are free to charge whatever the market will bear and i am free to buy the same tubes for much less elsewhere.

[richidoo]

Here's one... http://stores.ebay.com/atopauthenticauction

I feel fortunate to have the benefit of several serious tube experts on this forum. Thanks Bunky!
Rich

[musicfile]

Hi Bunky
Do you know where I can source some 6ca7 black treasures for my Dodd amps cheaper then what Grant Fidelity is selling them for

[Bunky]

I have been buying tubes and fuses from Hanshare Electronics using a free escrow service where they dont pay the vendor until you get the item and are satisfied with it. i am not kidding when i say that i will burn in the tubes, listen to them and then tell  www.aliexpress.com to go ahead and pay the seller    they also sell really nice Synergy Create Audio ceramic fuses with gold on one end and rhodium on the other. i will ask Ricky Xia to match me the best Quad or pair of tubes from his stock and he is more than happy to oblige my requests. i have had zero issues regarding sonics or reliability with anything that i have bought from Ricky Xia 

[Bunky]

Hi Bunky
Do you know where I can source some 6550 black treasures for my Dodd amps

as far as i know that animal does not exist. they do have the KT88-Z that should work,Gary Dodd is in the hospital and is very sick so i dont think we should bother him just now. what is the stock power tube type in the Monos ? EDIT you changed up on me ace   Hanshare carries the 6CA7 let me check the price for quads and i will pm you because we are starting to muck up Strings thing  

[musicfile]

Hi Bunky
Do you know where I can source some 6550 black treasures for my Dodd amps

as far as i know that animal does not exist. they do have the KT88-Z that should work,Gary Dodd is in the hospital and is very sick so i dont think we should bother him just now. what is the stock power tube type in the Monos ?

sorry looking for 6ca7
I heard about Gary ..here's wishing for a speedy recovery ..I understand he's stable at the moment
Were praying for you Gary

[richidoo]

Thanks Bunky.

[stringdriventhing]

Thanks for the greeting tmaz, good to make your acquaintance. Bunky, I'm glad to have your reassurance regarding non-Grant sources for Treasures. As pleasant as Rachel has been in my email exchanges with her, and as convincing as her argument can seem to be in regards to comparative levels of QA, the prices at GF take my breathe away. I'm gonna take a gander at Hanshare and I've already been to goodcomponent.com and found the pricing there much more attractive, especially considering I'm attempting to replace an entire system. The Stereo 90 is due to be delivered tomorrow, fingers crossed! - String