MC2301 amplifiers - Tube rolling 12AT7's

[crwilli]

You know you’re probably right Tom, I think the Siemens may work well in the MC275VI. They have a great midrange but did seem rolled off on top when I had them driving my Strads.

I would have to really listen to what the stage did though.

[W9TR]

My MC 275V is in a system that is already pretty laid-back so I’m rolling tubes to get a more forward presentation. SED Winged =C= KT-88’s,
Siemens ECC 801S, and GL 12AX7A’s are doing the trick now.

[audioquest4life]

Originally Posted by W9TR

My MC 275V is in a system that is already pretty laid-back so I’m rolling tubes to get a more forward presentation. SED Winged =C= KT-88’s,
Siemens ECC 801S, and GL 12AX7A’s are doing the trick now.

Where did you get the SED winged C’s? Are they the same as the Svetlana Winged C? I used the Svetlana Winged C and I thought they were the best KT88 at the time. Not sure how they compare to GLKT88’s, but they were very good sounding to me.

[W9TR]

I have a stash of SED Winged =C= KT-88’s in my tube collection. They are no longer available as new production.

SED winged =C= tubes were made by SED in St. Petersburg. The current Svetlana Winged =C= tubes are made by the Reflektor plant in Saratov, home of Sovtek, Mullard Reissue, Tung-Sol reissue, Electro-Harmonix etc.

I understand they are a different construction and different sounding tube. But I have never tried the new Svetlana Winged =C= tubes so have no personal experience with them.

In my MC 275V the SED KT-88’s have a more forward and detailed presentation compared to the reissue GL’s. Maybe a little tighter bass.

[rob725]

When I got the 901's, I told myself I would resist tube rolling, but this thread is weakening my resolve. The 901's use the same tubes as the 2301's with the addition of 1 12AX7A, which I assume is also a candidate for rolling.

Since the tubes are only handling 400 hz. and above, which tubes might be especially good for midrange/treble even if they may leave something to be desired on the low-end? I lean more toward a silky midrange than high-end sparkle.

[crwilli]

Originally Posted by rob725

When I got the 901's, I told myself I would resist tube rolling, but this thread is weakening my resolve. The 901's use the same tubes as the 2301's with the addition of 1 12AX7A, which I assume is also a candidate for rolling.

Since the tubes are only handling 400 hz. and above, which tubes might be especially good for midrange/treble even if they may leave something to be desired on the low-end? I lean more toward a silky midrange than high-end sparkle.

It’s likely a full set of matched Genalex Goldlion KT88s will add some air to the 901s but at a cost.

Of course, rolling in the smaller tubes (12AT7) is much cheaper and based on my experience, does have an audible impact. For these, my experience also suggests the GoldLions if you lean towards silky. In my recent journey, the GLs just add more goodness to the sound than I get with the OEM tubes. The Siemens EC801s were more forward than the GLs and add ‘more’ air than the OEM tubes. I preferred the GLs when all was said and done as they had the best balance.

[rob725]

Originally Posted by crwilli

It’s likely a full set of matched Genalex Goldlion KT88s will add some air to the 901s but at a cost.

Of course, rolling in the smaller tubes (12AT7) is much cheaper and based on my experience, does have an audible impact. For these, my experience also suggests the GoldLions if you lean towards silky. In my recent journey, the GLs just add more goodness to the sound than I get with the OEM tubes. The Siemens EC801s were more forward than the GLs and add ‘more’ air than the OEM tubes. I preferred the GLs when all was said and done as they had the best balance.

I've read elsewhere as well that less is gained from rolling the Kt88s than from the signal tubes. I like the sound of more goodness! I see you have the c1100; did you roll any of those tubes?

[crwilli]

Originally Posted by rob725

I've read elsewhere as well that less is gained from rolling the Kt88s than from the signal tubes. I like the sound of more goodness! I see you have the c1100; did you roll any of those tubes?

Yes. All Genalex Goldlions now except for the phono stages which I don’t use.

[W9TR]

I rolled GL’s into my C 1100 and kept them in for about 50 hours. I heard a very slight difference that I wasn’t sure was really better. So I rolled the OEM tubes back in and saved the GL’s for when the OEM tubes finally die.

[crwilli]

Originally Posted by W9TR

I rolled GL’s into my C 1100 and kept them in for about 50 hours. I heard a very slight difference that I wasn’t sure was really better. So I rolled the OEM tubes back in and saved the GL’s for when the OEM tubes finally die.

Can’t say I could hear a great difference as it is not a quick change. It took me almost an hour to complete and by then, I didn’t trust my ears. I probably wrote there was more air.

Anyhow, I bought my unit used so for me it was more a matter of establishing a known ‘Time 0’ with tubes.