HI FI AMPS and TUBES

[PoleSpeaker]

Happy Monday from Atlanta, everyone! Do we have any Home Stereo enthusiasts here?! I am guessing that is a big yes! I have a couple of questions:

1. Tube rolling, and assuming the other components in the power amp build allow for it, how much real change will I see between different power tubes i.e. EL34, KT120, and others?

2. I have learned and even more and drastic difference will be found between "small-tubes" or the line-stage portion...


My Product: a new Rogue Atlas Magnum III


Your advice, insights are appreciated. Thank you!

Kind regards,
Lance

[TwilightOdyssey]

If the amp and valves are new, the amp should ship and sound exactly as the manufacturer intended. You should consult the manual/manufacturer before swapping valve types. If you are looking to ALTER the sound of the amp, I would suggest calling Rogue and asking what they recommend. Hi fi is a different world than pro audio. Rogue makes good products, I’ve known Mark for years and used to run an audio boutique in NYC. I’ve owned a ton of valve gear (and high end gear in general) over the years though now my system is a simple Audio Research/Krell/Sonus Faber setup.

[beaubrummels]

To tube roll, you need to confirm the tube type, pin assignments and voltage specs are compatible with your amp.

The Rogue you have is 100 watts per channel using 2 KT120s, which I am guessing are in Class A/B, possibly running in triode/ultralinear for audiophile use - meaning they are not running near their rated limits in order to produce a clear accurate sound wave.. The only tube near to the KT120 specs I'm seeing is the KT88, but it's lower power rated, meaning it's likely all it would do is darken and distort the sound, if not cause other problems, e.g. slowly burn out the power trainsformer or some other components.

I guess the question is why do you want to change the tubes? Is there something wrong with the sound as came from the factory? Or just curiousity?

I 100% agree with TO's recommendation - it should sound the best it can already from the factory, and I would call Rogue before considering any modifications. If it doesn't sound right to you, I'd first look at something else in the signal chain (turntable, needle/cartridge, preamps, cables, speakers), or perhaps a different power amp is what you need.

[PoleSpeaker]

Hey, guys, really appreciate your sound advice (pun not intended). I do not even have the Rogue Amp yet; it was just ordered.

I did contact Rogue (Mark & Nick were very helpful) and they said tube rolling the "smaller tubes" (12au7 & 12ax7) made more sense and could
reveal a difference in tone compared to stock, but to wait for a couple of months before trying this, if at all.

So I am good for now. Thanks, guys!

[ehdwuld]

Welcome to the forum

Usually the first post doesn't include product placement

I thought you were a spammer

[AlexR]

Hi Fi has the tubes operating well within the linear portion of the curve. I would expect that you are going to see very little difference in tone, as it is my understanding that the 'guitar amp tonal difference' comes from the construction of the tube forming a limitation once pushed beyond design spec.

In Hi Fi too, you are looking for complete accuracy of input to output....merely louder. And if the maker has put in a specific set of tubes from new that likely will do the best (assuming a high quality maker) for that goal.
If you are finding you have an eq issue in the room, then speakers or maybe a quality eq processor is better for tuning the amp to the area the amp is in.

[PoleSpeaker]

Hello, EHD and Alex - actually the manufacture pointed out their specific build is very well balanced - as I mentioned above, of course i will try their design for months before (if ever)
I try tube-rolling.

This said, there is a lot of difference in Tone between different preamp-section tubes, and depending upon the rest of ones hifi set up (there is so many variables) will notice more or
less these specific characteristics. We shall see. Appreciate your input! Thank you.