Hi, and Bad Cat amp question

House4755 · Newbie Alert Joined: 23 Oct 2008 Posts: 4 Location: Ohio

Hi all,

I just found this forum while searching for Bad Cat retubing info.

I'm a female, geezer generation guitarist still gigging in the Southwest Ohio area--used to play full time but we're weekend warriors now.

Nice to be here & meet you all, and here's my question. I'm pretty non-technical, so feel free to dumb down your reply Wink

I'm retubing my Bad Cat Cub 2x10 combo, to try to solve a "reverb died" issue (plus it's about due anway). Last time I retubed, I called Eurotubes & used what they suggested, all JJ Electronics tubes--2 EL84s, 1 GZ34, 4 ECC83S standard, and 1 ECC83S balanced for the phase inverter position.

James at Bad Cat suggested I use Ruby 12ax7 (chinese) in place of the EC83s for more chime, and I picked them up, but I'm not sure what the deal is for the "balanced" ECC83 for the phase inverter. I'm wondering if I can just use another 12ax7 for this?

If anyone knows something about this, I'd appreciate it--

Thanks, and nice to meet you!

Jan House

tw001_tw · Posted: Thu Oct 23, 2008 11:09 am Post subject: Re: Hi, and Bad Cat amp question

House4755 · Newbie Alert Joined: 23 Oct 2008 Posts: 4 Location: Ohio

Thanks tw001_tw!

Yes, that does help, and thanks for the lesson on phase inverting, I understand much better now. I'm retubing today, it'll be interesting to see if my reverb recovers.

I also got an email reply from James, and he said the same thing you did, no problem using the 12ax7.

Nice meeting you!

Jan House

tw001_tw · Posted: Sat Oct 25, 2008 6:33 am Post subject:

House4755 · Newbie Alert Joined: 23 Oct 2008 Posts: 4 Location: Ohio

Well, I retubed yesterday.

I got the new Ruby 12ax7ac5 (per James' suggestion, he said that or Groove tubes--I was under the impression Ruby tubes weren't great, but he said he liked the chime of the Chinese ones). I got them from Parts Express, nearly ordered them from that store at Amazon before I realized the store is 20 minutes up the road from me, so I went directly to the store. Paid tax though; the price was okay. I've used Eurotubes before & really like them--very helpful when you call, and good prices. I didn't see Ruby in their catalog, though.

I used JJs in the rectifier (GZ34) & EL84 positions.

I'm very non technical, but I've learned to trust my own ear & not read so much hype on the internet. I found some very good pointers on tube changing on the Eurotube website, and used contact cleaner on the pins of the new tubes for better contact, and pushing the tubes in & out a few times to clean the sockets somewhat.

The amp sounds stronger & more present, good harmonics, and maybe just a tad harsh. It's hard to say without gigging, and this amp really sounds great--kind of swirly--I'm not sure if there's harshness there or it's because it was just sitting flat on a hardwood floor in a room with hard surfaces in my house. I'm going to put it on the stand I normally use & work with it today. I may change out the new Ruby preamp tubes for the older JJ's & see what difference I hear.

Sadly, the reverb issue isn't fixed, I was hoping it was the tubes. Even all the way up, there's just a faint bit of reverb, hiding behind a dry guitar signal, if that makes sense. I'm going to do what I can to troubleshoot it--I've never fooled with a reverb tank & other than trying different cables, I'm not sure how to proceed.

Overall, regarding the tubes, I think I'll be experimenting & seeing what combination I like best. I'll probably learn a lot from this site, so I'll be hanging around Wink

tw001_tw · Posted: Sun Oct 26, 2008 6:11 am Post subject: Re: bad cat cub amp

House4755 · Newbie Alert Joined: 23 Oct 2008 Posts: 4 Location: Ohio

thanks for you interest, tw001_tw!

I may have a voltage meter floating around--I thought I might get into working on amps a couple of years ago, but soon found out I lack that kind of talent Wink

If checking the tank with a meter is a fairly safe thing to do, I'm game for that--I was going to swap the tank from my Hot Rod Deluxe & troubleshoot the Bad Cat tank that way, but found on the internet it might not be that easy. They're both Accutronics (sp?), but different models.

I was going to call Accutronics Monday & find out more about swapping those, or replacing. It might be worth 30 bucks to change a tank vs finding a good amp tech for this amp--with drive time & gas, turn around time, and bench fees, well, you get the idea. Most techs around here have never heard of a Bad Cat -- one guy thought I was looking for a veterinarian. . .

tw001_tw · Posted: Sun Oct 26, 2008 7:17 am Post subject:

The quick and dirty way of testing the reverb pan and
recovery circuit - With the amp on, volume rather low, hit the reverb
tank with your hand - if hit hard enough, you should hear a reverb
crashing sound which is very unpleasant. (Have you ever picked up,and
then set down the amp while its on? same thing ).

Nothing wrong with visually inspecting the reverb tank either.
Inspect solder connections, etc. taking a resistance reading of those little
transformers (part of the transducer) they should read anywhere from
160 to 200 ohms - somewhere in that ball park. This would also be a good
time to double/triple check the cables connecting the amp to the tank.

(ignore those green circles)

Theres a lot of different types of reverb tanks - but if both your amps have
tube driven reverb circuits, they should be close enough to work on
the other amp - one might have a longer decay / 3 springs instead of
2,etc. but just for a 5 minute test - again, if they are both tube driven, a
switch of tanks for testing should be just fine.