janlf
Full Member
Moment's Notice
Posts: 173
|
Post by janlf on May 9, 2008 22:11:30 GMT -7
Hi!
I have a fairly new Maz 18jr 1X12" reverb combo and thought about swapping some preamp tubes around just to see what more amazing sounds one can get out of this great sounding amp that I love. Can I put "any" of the 9 pin dual triode tubes in there or would something like a 5751 or EF86 do some damage. I basically thinking about V1. Any thoughts or suggestions?
Sincerly, JanLF
|
|
|
Post by benttop (Steve) on May 10, 2008 7:39:40 GMT -7
EF86 is not compatible, but you can put any of the 12A family in there (12AX7, 12AT7, 12AU7, etc.). Some of those aren't good candidates but the 5751 is a real popular substitute in V1 for guys who want a bit more clean headroom.
I wouldn't do any subbing on the reverb tubes though...
|
|
janlf
Full Member
Moment's Notice
Posts: 173
|
Post by janlf on May 10, 2008 12:35:24 GMT -7
Hi, Benttop.
Thanks for the reply. Stupid of me - of course the EF86 is a pentode, not a triode. Anyway, what's the main difference between a AY7 and the 5751 if there's a simple and/or easy way of describing it. Is the gain ca. 37 vs. 70 and are their any other sides to this to be concerned about. And could you please elaborate a little about the non-subbing of reverb driver/recovery tubes?
Greetings from Norway, JanLF
|
|
|
Post by benttop (Steve) on May 11, 2008 10:36:03 GMT -7
Well I'm no expert - not much of a tube substitution experimenter here I guess. But you're right that there are going to be gain differences. In addition, some of the 12A series were designed for duties other than audio gain, so while they may actually work, they may not sound all that great. Let your ears be your guide. You'll probably find a lot more guys who have experience doing this over in the tubes section. I rarely read there because I'm pretty pleased with how my Z amps all sound with the factory tubes in place.
As to the reverb driver and recovery, these tubes have been selected specifically and their circuits designed specifically to drive the reverb transducer and be driven by the reverb recovery transducer. You might get some improvement of tone by swapping to NOS tubes of the same designation, but if you try to put lower gain tubes in there, or higher gain for that matter, it is doubtful you'll have an acceptable result. Here again, I've not done any such experimenting, so YMMV, but I doubt you have nearly the latitude here as you have in the normal signal path.
|
|
|
Post by mikekca on May 22, 2008 6:24:29 GMT -7
|
|
|
Post by benttop (Steve) on May 22, 2008 7:06:54 GMT -7
Thanks for that! Think I'll keep that link bookmarked.
|
|
|
Post by funknbluezer on Jul 3, 2008 12:39:06 GMT -7
I have several questions regarding swapping out tubes. Please forgive my total ignorance on this subject. I have a Stang Ray 1x12 combo. Will I harm the amp in any way shape or form by swapping out the rectifier tube? I have heard that a 5Y3 or 5Y4 would soften the amp up a bit. Also, I would like to put a 12AT7, 12AU7A or a 12AY7 to get an earlier breakup. I have heard that the 12AY7 requires a plate load resistor for at least one watt, whatever that means. What I'm trying to do is move the sound of the Stang Ray to a bluezier type amp for small venues. Like I said, Im no expert on this tube swap thing.
|
|
janlf
Full Member
Moment's Notice
Posts: 173
|
Post by janlf on Jul 10, 2008 7:30:43 GMT -7
Hi!
I'm unsure about the rectifier swap, but the 3 tubes you are mentioning will break up later than a 12AX7. Otherwise than that they are all "technical" swappable. You could also use a 5751 for less gain.
JanLF
|
|