Jetta tube info

[heybulldog]

New Jetta owner here. I think this amp was built just for me. How long should we expect the power tubes to last?

[mrcapers]

I'm sure it was just a fluke, but I lost one 7591 with less than 30 hours on the amp. No big deal, I have other Zs to use, but if this is your only amp you should buy a spare pair. They're all but impossible to find locally.
I love this amp! My Z-Plus is getting jealous ;-)

[Jaguarguy (Mike)]

Tubes are a crap-shoot these days. I have spares for everything.

[DRZ]

Dec 31, 2019 10:22:40 GMT -7 Jaguarguy (Mike) said:

Tubes are a crap-shoot these days. I have spares for everything.

And unfortunately getting more expensive for lower quality each year .
I love designing combo amps, it allows me to completely control the overall tone and sound of the design.
But output tubes all have become more and more plagued with varying amounts of rattle, which is made worse in a small combo.
Tube manufactures all refuse to re-tool there dies, these dies have been used beyond there shelf life, precise dimensions are not held in tolerance
hence poor fitment and internal rattle.
Tube amp heads seems to be the logical answer to this issue.
I will be filming an AMA which will explain this problem.

Z

[heybulldog]

Thanks everyone.
When I buy a set of spare 7591s, is there a matching number (idle current) i should ask for? Lower numbers seem to work better for my other cathode-biased amplifier.

[rickyp]

Dec 31, 2019 9:38:55 GMT -7 mrcapers said:

I'm sure it was just a fluke, but I lost one 7591 with less than 30 hours on the amp. No big deal, I have other Zs to use, but if this is your only amp you should buy a spare pair. They're all but impossible to find locally.
I love this amp! My Z-Plus is getting jealous ;-)

I’ve got a Z-Plus...been looking at something to add to my collection with more clean headroom, mainly for gigging purposes.
How would you say the Jetta compares with the Z-Plus as far as clean headroom goes, at gigging volume?

[mrcapers]

Just saw this. The Jetta has much more headroom than the Z-plus. The Jetta can get loud! I gig with the Z-plus on full power with the master at noon, the Jetta's master is around 9:30 for the same volume. Tonally they are different, the Z-plus is like a HiFi amp, the Jetta doesn't have the top end sparkle. The Jetta has much more bass than the Z-plus. Some day I'll try the two together.