What is correct pre-amp tube for Ashdown EVO 300 ??

[DHowardAir]

I have an Ashdown (first generation / UK made) EVO 300 combo amp with 1x10 speaker. It is not the EVO II or MAG, etc. First series made. i think it is about 10 to 12 years old.

Where can I find the correct make & model of pre-amp tube for it? I want to change it but can't take it apart right now as I am using it this week. Thought I would go ahead and order the tube before I pulled the head out of the cab.

I went to the Ashdown site but couldn't find it on there.

Any help greatly appreciated.

[RickenBoogie]

Unless it isn't working, there's really no need to change it out. Most preamp tubes can last for decades. Anyway, if it's just a single preamp tube, it's most likely a 12AX7.

[scowboy]

my abm500 has a 12ax7

[grendle]

Might wanna try a 5751 in there. Much better and hi fi sounding than any 12ax7 imo.

[BruceBass3901]

You could try asking on their Facebook page or emailing Ashdown directly. In my experience, they are always more than happy to help out

[Hathernman]

I replaced the pre-amp tube in my ABM 500 with a Groovetubes 12 AX7- recommended as a mod in a posting some time ago. Worked really well, and, though subtle, seemed to add a bit more tube grind. Dead easy to do - just take out the amp head, unplug the old one, plug in the new!

[GeoffByrne]

Originally Posted by grendle

Might wanna try a 5751 in there. Much better and hi fi sounding than any 12ax7 imo.

+1!

This will give you more headroom at the cost a *slightly* less total maximum volume - depends if your volume knob is dimed all the time!!! Many HiFi buffs will tell you the 5751 is the best tone generator of them all.

If you go that way make sure what you are getting is a genuine 5751 design & not a 12AX7 that failed its Gain-test - there's a few around, just re-labelled poor quality 12AX7s - the plate design is different.

Anyway if you want more grind you could try & get a European-made NOS ECC83. Technically these are the same as 12AX7s, but in practice you'll find the NOS European/British made ones often have a bit more mid-range & that'll add to the grind if that's what you're looking for.

Welcome to the fascinating world of tube-swapping!!!!

G.

[BassmanPaul]

Originally Posted by RickenBoogie

Unless it isn't working, there's really no need to change it out. Most preamp tubes can last for decades. Anyway, if it's just a single preamp tube, it's most likely a 12AX7.

+1. Or 7025, ECC83