Bad Cat Mini Cat

Post by **modman** » 13 Feb 2008, 11:30

hey, there is a lot of commotion around this $1500 Japanese (168 000 yen) 5 watter... Do you own one? Would really like to hear some non HC analysis on this one, they are down to outright insults over this one...

Found this 'cutie' - but that's all she is I'm sure
http://www.digimart.net/gk_detail.do?in ... DS00202878

thanks for posting though!

oscarv77 · Post by **oscarv77** » 13 Feb 2008, 21:02

Does anyone know what kind of transformers it uses? I have some spare parts lying around and this looks like a fun little project.

Ronsonic · Post by **Ronsonic** » 14 Feb 2008, 15:16

Output tranny is probably a fairly standard 8K-8R. Pretty much anything off a single 6V6 or EL84 or such.

The power tranny depends on what you have and what sort of rectifier you use. Don't see a reason to hunt for something that works for the bridge if you've got something like a 250-0-250 and a tube recto. The Duncan Power Supply Designer is well worth a download and can show you what you can do with what you've got.

Ron

oscarv77 · Post by **oscarv77** » 14 Feb 2008, 17:25

The reason I asked is because I got a tube turntable amp and adapted it for guitar use (it sits on my bench to test pedals with). I already have the power xformer and the output xformer so I was curious to see if I could adapt/build this amp using that iron.

I'll post pics and xformer numbers tonight.

Ronsonic · Post by **Ronsonic** » 15 Feb 2008, 16:00

Pics and part numbers won't help, but....

If your amp is running a single 6V6, 6AQ5 or EL84 we can presume the OPT is okay for the job and pretty much the same for the power supply. See what B+ voltages you've got and go from there. If you've got anything in the 300-350 VDC range it should be good.

I can't tell you how many projects I built from an old tubed gear that landed in Goodwill.

Ron

oscarv77 · Post by **oscarv77** » 16 Feb 2008, 03:41

Ronsonic wrote:Pics and part numbers won't help, but....

If your amp is running a single 6V6, 6AQ5 or EL84 we can presume the OPT is okay for the job and pretty much the same for the power supply. See what B+ voltages you've got and go from there. If you've got anything in the 300-350 VDC range it should be good.

I can't tell you how many projects I built from an old tubed gear that landed in Goodwill.

Ron

It has 3 tubes (6V6, 6X4, and an unidentified RCA tube). The power xformer has TR-196-606-1-04 and the output xformer: TR-212-606-1-03

I'll power it up and see what kind of voltages I get.

Ronsonic · Post by **Ronsonic** » 18 Feb 2008, 03:59

It sounds pretty close to perfect for the job. The 6X4 is the rectifier and pretty what you'd expect to see powering an amp like this. 6V6 and EL84 are very similar in their power requirements, check your voltages, but even sight unseen I'd hit it.

I have no idea how good that circuit design is, but there's nothing worrying in it and I've never seen or heard a bad EL84 amp.

bajaman · Post by **bajaman** » 18 Feb 2008, 04:26

I've never seen or heard a bad EL84 amp.

100% in agreement Ron

EL84 tubes are THE best sounding tube on the planet

cheers
bajaman

shicky · Post by **shicky** » 15 May 2008, 14:54

This might be a stupid question.
I want to try to build this amp.
is 100R = 100 ohm?
Will 1/2W resistors work fine?
thanks in advance

KHELSTROM · Post by **KHELSTROM** » 15 May 2008, 18:06

shicky wrote:This might be a stupid question.
I want to try to build this amp.
is 100R = 100 ohm?
Will 1/2W resistors work fine?
thanks in advance

Yes 100R is 100 ohm and 1/2 watt resistors will be fine unless noted otherwise in the schematic. I see that the picture of the schematic I posted is cut off so PM me if you would like me to send you a copy.