Input & driver tubes vs output tubes

GlennDog

A few months ago I picked up tube mono blocks . . . Rogue M180s
I was finding myself resetting the bias every 3-4 days, so I replace the output tubes. It made a huge difference. The bias meters stay almost dead-on over 30 days. And I can honestly say the bass is digging deeper and without a doubt there's a lot more noticeable decay.

So I'm wondering what difference good quality input and driver tubes will make.
I'm looking at these and they seem expensive

https://app.audiogon.com/listings/tubes-telefunken-12ax7-4-very-nice-telefunken-rib-plate-12ax7-tubes-test-like-new-2014-12-06-accessories-48340-pontiac-mi

will new input and driver tubes make a big/noticeable difference like the output tubes did?

Any thoughts are appreciated as I'm kinda new to the tube world

F1nut

Yes, they can make a huge difference.

GlennDog

F1nut wrote: »

Yes, they can make a huge difference.

Thanks! appreciate the input

what do you think about the ad on the gon, is the guy off his rocker regarding his asking price?

Faustin

I am relatively new to tubes as well, but I have been watching tubes on various sites on the web and the prices are crazy. Especially when the same tubes were selling for a buck or two 30 years ago. Seems like Telefunken, Mullard, Bugle Boy etc are crazy priced. One way to go is to look for strong used organ tubes. They were made by the big manufacturers, tested for low noise etc and private labeled for the organ manufacturers. I bought a pair of 12ax7 black plate Raytheon tubes that were made for Baldwin organ for around $40. I am happy with them. The military tubes are another way to go for less money. They were made to handle the abuse of being bounced around and were made for low noise. I am having a hard time paying $50 on up for tubes.

Faustin

Hey Glenndog, take a look at these 12ax7 tubes. Not sure how many you need.

http://www.ebay.com/itm/161537586458?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

voltz

^^^^
those are saying AT&'s not AX7's

All my Amperex & telefunken are have great sound but are very micro-phony sounding to me, touch the side and you hear it. my Jan-sylvanias are boring but quiet... as are the psvane I bought...now my Mulluard i got from tube depot sound great in my MC100b are are affordable

https://www.tubedepot.com/products/mullard-cv4004-12ax7-new-production-preamp-vacuum-tube

think these are the same one Marvin uses in his Mc-100b also.

marvda1

Faustin wrote: »

Hey Glenndog, take a look at these 12ax7 tubes. Not sure how many you need.

http://www.ebay.com/itm/161537586458?_trksid=p2060778.m1438.l2649&ssPageName=STRK:MEBIDX:IT

those are 12at7's.

voltz

that was almost a tie Marvin but your right

Faustin

My mistake. Watching 12ax7 and 12at7 tubes. But the main point remains.

GlennDog

The output tubes are a newer design, about 5 years old or so (I think). I am not sure if the (driver) 12AU7 and the (input) 12AX7 are the kind of tubes that you Roll.

I'll refresh the 2 inputs tubes and 4 drivers. If I go new production i'll be about $25 or so a pop . . . Some vintage NOS is off the charts

Thanks for the replies!

Mike Reeter

I've tried several NOS AX7's in my Rogue Cronus, the Telefunken (ribbed or smooth plate) are one of my favorites.

I've paid around $100-140 for a matched pair, the A'gon add is not that far out of line.

A Black Plate, 3 Mica, D Getter RCA is also very good in the Rogue.

Just about any NOS tube will sound sweeter than any original tubes supplied with the amps.

GlennDog

Thanks guys, I'm seriously leaning toward these . .

http://app.audiogon.com/listings/tubes-sylvania-jhs-military-spec-12au7-blackplate-with-angled-square-getter-circa-1950-s-2014-12-05-accessories-l8g4w6

Your thoughts on SQ quality & fair price$