[jazpresso]

right now i've one sovtek 12ax7lps, one jj 12ax7, one rca 12ax7 (from england) one pair of jj el84; can anybody teach me how to make a best mix for them work together? and i also see a philips 12ax7 in one shop, the shopkeeper said that philips sounds 90%similar to tfk 12ax7, does anybody know it?

 

[Gallaine]

Here is a recent thread discussing tubes and the MG Head:

http://www4.head-fi.org/forums/showt...d+tube+rolling

Try doing a search as this subject has been discussed many many times.

From your post you only have one pair of EL84's. So, install those and then just listen to each of the 12AX7's and find out which one you like best.

 

[braillediver]

The Telefunken 12AX7 isn’t regarded as a great tube in the MG Head.

Sylvania JHS 5751 3 mica Black Plate, then the GE 5751 3 Mica Black Plate are excellent tubes. For the 12AX7’s an Amperex Bugle Boy sounds really good. Some of the 12AU7’s would be a good try also.

Famous guitar amp tubes don’t make for great headphone amplifier tubes.

I’ve recently grown partial to the RCA 12BH7A. It’s different from the12AX7 in appearance in that it looks like it’s on steroids. It’s almost physically as large as the EL84’s.

Watch out for the Sylvania 5751 Gold Brands. I’ve had 3 and they’ve all been very noisy. With a terrible back ground hum , unusable really.


Mitch

 

[YoNni22]

I did a review a while back on serveral tubes. Here is the link
http://www4.head-fi.org/forums/showt...threadid=13469

YoNni

 

[merc]

I just got my MG Head OTL (last version), plus my source, JJ EL84 and various 5751 tubes (thanks NICK!!!), so I can't say too much for now. But, after only one night of 5751 rolling, I think I know which ones I like best and why.

I'll try and post my opinions on the latest MG Head OTL, not the Mk 2, and the tubes that I like best, as soon as I can...

In the meantime, I've experienced no humm at all, and have had the hardest time just determining if I like feedback on or off, while using only the OTL output? Probably, I'm gonna find that the feedback circuit is only heard while using the transformer output... ?

Stay Tuned!

 

[jazpresso]

yesterday i went into a tube shop, and ask for the tube of 12ax7, the shopkeeper had his work, he was repairing a tube amp. and when i asked him to look for a tube, he introduuce me some 12ax7, and also i asked him how about 5751. he didn't recommend me to buy 5751 becasue 5751 the volume gain less than the 12ax7. so i make my mind to choose the 12ax7, finally i have two choice, one is philips 12ax7 (tfk clone), and the other one is sovtek 12ax7. the price of philips is higher than the sovtek.
so i bought the sovtek and leave the philips next time, and the shopkeeper said the sound of philips much better than the sovtek. is he right? can anybody tell me?

when i came back to home, i plugged my jj 12ax7 out and plugged the sovtek 12ax7 in my mg head otl. and warm up the machine about 2 hrs. i picked up my k501, i feel the sound of sovtek as not good as my jj 12ax7. i think it need some time to run-in?

 

[dd3mon]

Don't let a shopkeeper turn you off to a 5751, I'd bet he's had no experience with an MG Head - that's where the real magic happens! The lower gain is hardly noticable (maybe 1/8 of a turn or less on the volume knob difference) - but on the whole 5751's sound much better in the MG Head than most of the 12AX7 tubes I've tried. I'm currently using a NOS 1980's GE Grey Plate tube (bought from triode - very cheap) with Chinese stock power tubes (better than the JJ el84's in this combination IMO) and it sounds wonderful to my ears (you can look at my impressions of all the tubes I've got here)

-dd3mon

 

[Sovkiller]

Here are two complete reviews of the most common ones...

http://www.nickdangerous.com/misc/mghead/index.htm

http://www.nickdangerous.com/misc/mg...estubelore.htm

 

[Gallaine]

I would have to agree, don't let the shopkeeper talk you out of the 5751 tubes. I've auditioned the Mullard CV4004, Telefunken ECC83s, and GE lps 12AX7s and the Tung Sol and Raytheon w/Windmill Getter 5751s. I preferred the Raytheon 5751 over all them.

 

[SumB]

I mirror everyone's opinion on the TFK 12AX7. It's a dull and uninspiring tube in the MG-Head.

 

[Sovkiller]

If you read Joe commnets, all the 12AX7, even the better ones like this telefunken, are considered with the same uninspiring sound, the 5751 has lower gain but is a lot better overall tube in this cases, read the review here. IMO, one of the better qualities of the telefunken is the durability (but not the sound itself):

http://www.nickdangerous.com/misc/m...oestubelore.htm

I have one Raytheon windmill that is a treasure, I keep it just in case for my next tube amp, but if the gilmore result in waht I was looking for, I will sell it, the sound is simply incredible, you can contact mitch he always have something good for sale, I got from him a GE5751WA black plates triple mica, that sounds extremelly similar to the Rayhteon if not better, I have to sell it with my old MGHead, but I would like to keep it also....

 

[merc]

Well, after a few nights of rolling, I prefer the Sylv JHS and the ITT 7025 best, each for different reasons. Next up, I like the Raytheon windmill getter and the GE 3 mica blackplate. The tung sol is also very nice but it is fatttttt(not phat), and can be overly so with most music for my tastes.

I am using the JJ EL84 tubes for all my 5751 rolling....

Tomorrow, I will be switching to a tubed source... and so my preferences may altogether change after that... probably the ITT might be my fav in that setup...?

 

[Nick Dangerous]

Heh... and I thought the ITT was going to be a throwaway after picking it up from eBay for $3.

 

[merc]

Quote:

Heh... and I thought the ITT was going to be a throwaway after picking it up from eBay for $3.

Dangit Nick! And, then you sold it to me for for something like $50... (jk).

BTW, well worth every penny...

 

[Kevin P]

So Merc is in the MG Head saddle again!

I have the Raytheon windmill getter 5751 in the center slot in my Head. Even crappy sounding CDs are listenable on this rig, and well-recorded CDs really sing! Maybe someday I'll try rolling other tubes like the often-talked-about Sylvanias, when I have money again.