Vintage HiFi Audio Forum

Audio Discussion => TUBES TUBES TUBES => Topic started by: Meles on March 01, 2015, 02:28:31 PM

Title: 6GK5 Tube Rolling (Melos, Loesch, CJ preamps)
Post by: Meles on March 01, 2015, 02:28:31 PM
The Contenders:
Mullard 6GK5 - a midrange tube sound champ, but it is an unreliable version, of an unreliable tube
Hitachi 6GK5 - everything the Mullard is not, but no mids
Westinghouse Japan 6GK5 - most are simply Hitachis
Japanese 6GK5 - images attached with angled getter. It seems to take a very nice spot in between the Mullard and Hitachi sound
Italian 6GK5 - well had one of these originally in preamp and later preferred Mullard, but a contender
American 6GK5 - I've not found many good ones

The problem with acquiring and trying 6GK5s is they are so cheap. The dealers just want to have one listing and can't be troubled to break them out. I can't find Italian 6GK5s (my buddy across town probably has a pair). Ditto the angled getter Japanese 6GK5.

My own Loesch pre uses these in the phono stage. I know the Melos GK-1 which seems to be popular in the community is chock-full of them.

Please respond with your thoughts and favorites.
Title: Re: 6GK5 Tube Rolling (Melos, Loesch, CJ preamps)
Post by: OldiesButGoodies on March 01, 2015, 03:06:47 PM
I only tried Americans and NOS Mullards on mine,  and the Mullards always seem to sound best.
Title: Re: 6GK5 Tube Rolling (Melos, Loesch, CJ preamps)
Post by: Meles on March 01, 2015, 03:48:05 PM
I only tried Americans and NOS Mullards on mine,  and the Mullards always seem to sound best.
The Mullards definitely have tube magic and the typical US one is a real step back in every way. The Hitachi has a very high end sound that now surpasses the Mullard I think overall if a bit clinical. It just seems to give a very accurate solid state like presentation without any editorializing.

The angled getter unknown Japanse 6GK5 in the photos is really interesting and has sparked my interest in the Melos Gk-1 and +1. It is another strong contender which I think completely bests the Mullard (though I've not done extensive back in forth between the two since its been up against the Hitachi).

All three sound quite good. I am a little surprised I've not seen much mixing and matching of tubes in the various stages for CJ and GK-1 owners.
Title: Re: 6GK5 Tube Rolling (Melos, Loesch, CJ preamps)
Post by: Sir Thrift-a-Lot on March 01, 2015, 05:28:12 PM
I don't have anything that uses this tube, but there is an RCA on ePay for $.99.   I've liked them in other things.
Title: Re: 6GK5 Tube Rolling (Melos, Loesch, CJ preamps)
Post by: Meles on March 02, 2015, 03:31:32 PM
I don't have anything that uses this tube, but there is an RCA on ePay for $.99.   I've liked them in other things.
Anything above $5 is too much for a 6GK5, but that is the problem Sir Thrift-a-lot. If one cares to roll the typical 12ax7 or 6dj8, all the top examples are codified and up for sale on epay and you just missed out on this great deal:
Vintage/NOS Genalex Gold Lion B759/12AX7/ECC83 Matched Pair!
$2,402.17
14 bids
+$5.95 shipping
(I happen to have one of these used and can roll it in the power supply of my current preamp, where I've rolled most of the top 12ax7. As you can see, this tube rolling can get out of hand.)

With a 6GK5, sellers feel put out just making the effort to list one. Typical tube dealers will just have an entry 6GK5, $5. They won't even break them out each brand into seperate entries.

So 6GK5 tube rolling is not known well and i bring my images of the humble slant getter Japanese 6GK5 as a scoop of sorts for the local denizens.