SP Extreme/Platinum tube guide spreadsheet

[bmclaurin]

New and improved!! (see edit below)

Guys, I now have an Extreme Platinum on order, and I've been combing through the forums over the last few days trying to make sense of the bewildering array of tubes available for this amp. After a while, my head started to spin, so I decided to start capturing the information in an Excel spreadsheet. As the spreadsheet began to come together, I thought I would post it here as it might be beneficial to others that are looking to tube their Extremes or Platinums. This is a rough work in progress at this point, and it probably contains several errors, so please use it at your own risk!

There are lots of really excellent threads out there, like this one and this one and this one that talk about the various tubes and combinations, but I couldn't find anything that really pulls it together like I was looking for, which is why I decided to create this spreadsheet. Please keep in mind that I'm a complete novice when it comes to tubes. I've never owned a tube amp before, so I'm sure that the spreadsheet will have some inconsistencies and errors at this point.

Please also keep in mind that I selfishly only focused on tubes suitable for the Extreme, including the Extreme Platinum. So there are tons of other tubes and combinations out there that might be completely awesome for the PPX3, MPX3, Supra, etc. that aren't suitable for the Extreme. Those tubes were thus excluded from the spreadsheet.

I basically started with the compatible tubes listing sent to me by the good folks at SinglePower and then began adding to it additional information that I found in various posts on this forum, especially Earl's excellent "The Extreme has arrived!" thread, which has become probably the most complete single thread on Extreme-specific tubes out there. Probably the most beneficial part of the spreadsheet are the many links it provides to the various comments made by several different folks about that particular tube or tube combination.

You'll see two tabs in the spreadsheet--one for tubes and one for tube combinations, which should be pretty self explanatory. I'm quite certain that the Tubes tab is not an exhaustive list of everything that's out there, but it does capture most of the more popular tubes that have been mentioned frequently in this forum. The Combinations tab just lists out the various gain/power combinations that have specifically been mentioned from time to time on these forums. There are almost literally an infinite number of possible combinations out there, so this clearly is not an exhaustive listing.

Feel free to do with this whatever you want. If you guys find it useful and want to keep it current, by all means, have at it. In fact, if this catches on and you guys want to reply in this thread with corrections or whatever, then I'd be happy to update and re-post the spreadsheet periodically. On the other hand, if you want to leave it there to laugh at it and throw darts at it, then that works for me too. This spreadsheet is simply how I, as a certified tube novice, have tried to get my head around this pretty confusing (but fun and exciting) concept.

Lastly, let me just say thanks to all the veterans out there that have spent untold, countless hours listening to these things and reporting on your impressions. Your efforts alone have given me the confidence to open up my wallet and dive in to this great hobby of ours.

Barry

EDIT: Updated spreadsheet (v2.01) now captures all of the most popular, recent (as of July 5, 2007) threads discussing Extreme-specific tubes. Also now includes for the first time electronic specifications for most tubes, including heater voltage and current, and plate voltage and current for Class A amp operation, including amplification factor (μ), which is useful for matching tubes to headphones of different impedances.

[Rob N]

Good stuff!

A few things I've noticed

6BX7/6BL7 - used as output tubes in non Extreme SP amps which have octal sockets and suitably large power transformer to cope with extra heater current required.

6SU7GTY - specially selected 6SL7 octal socket so (for most SP amps) no adaptor need,high gain,input tube.

You can add this - 6385 - Bendix Red Bank version of 2C51/396A,500ma heater,rare and expensive

5998 & 6080 do not need an adaptor they plug straight into the output sockets on an Extreme

7062 = E180CC.SQ = "Special Quality" a designation only used by Philips owned companies (incl Mullard)

You can also use the 6085 = E80cc as an input tube (similar to a 12AU7) but in a tall bottle.

Also you can use the 7308 an uprated version of the E88CC/6922

[bmclaurin]

Thanks, Rob. Spreadsheet has been updated accordingly.

Barry

EDIT: I removed the 6BX7/6BL7 from v2.01 of the guide since these are non-Extreme tubes.

[bmclaurin]

OK, not that you guys seem all that interested in this, but I think I have now covered all of the most popular threads that discuss Extreme-specific tubes. The spreadsheet has been updated to include links to all of the key comments contained in those threads.

Barry

[ldj325]

Great job! Thanks for putting this together.

Enjoy the Extreme Platinum, it's a great amp.

[panyncor]

Wow, Barry, what a great resource -- this is really excellent. I wish I'd had something like this months ago. I admire your patience in putting it together, and I'm glad you chose to make it available.

If you plan to keep this up, I would suggest removing "Sylvania" under 6sn7 manufacturers, as there are many, many varieties of 6sn7s that will work in the Extreme. Also, maybe it's just re-branding at work, but I have several examples of tubes that appear to be from manufacturers other than those you list (e.g. Tung-Sol 6080, GE 6as7g, and Sylvania 6as7ga).

These are very minor quibbles -- thanks again for sharing. I'll be referring to this when I make my next round of purchases.

[nelamvr6]

You guys may find this link informative, I know I did.

[bmclaurin]

Originally Posted by nelamvr6

You guys may find this link informative, I know I did.

Awesome...thanks. I had not seen that before. Now I've gotta figure out how to get all that information into my spreadsheet!

Barry

[Tbln]

Keep up the good work Barry!

Invaluable resource for SP Extreme amp owners.

Thanks!

[vberch]

Thank you very much Barry! This is a great resource!!