Fender Champion 600

[Spudman***]

I just stumbled across this demo and he's using the new Squier Classic Vibe Tele too.

[tot_Ou_tard]

Sweet, sweet, sweet. Thanks Spud!

Someday I'm gonna upgrade the transformer on mine.

[tunghaichuan***]

Someday I'm gonna upgrade the transformer on mine.

I was just in Guitar Center today and happened to look in the back of the cabinet. There is not a lot of room for a new OT. I doubt if a Hammond 125CSE would fit in there. If I had to guess, I would guess that the mounting centers are 2 & 3/8", but you might want to measure for yourself.

One OT that might work is the Fender Champ 12 replacement OT. It is a 10watt unit that has 2 & 3/8" mounting centers, but it is about 1" taller than the stock OT. It also only has an 8ohm secondary, so you'd have to find an 6", 8 ohm replacement. It is also kind of expensive, about $40-$50 IIRC.

Another OT option is this one:

http://store.triodestore.com/tfchxfwi48oh.html

It has a 4 ohm tap and an 8 ohm.

Finally there is this one:

http://www.turretboards.com/valve_ju...placement%20OT

Again, kind of pricey, but it is a Heyboer, so it will sound good. It has 4/8/16 ohm secondaries. It it is billed as a Valve Junior replacement, but with the 6.6k primary, it is more suited for use with a 6V6.

Let me know if I can be of any help when you decide to change out your OT.

tung

[tot_Ou_tard]

tung,

I'd love to hear more about how OT's affect the sound. I have no experience & find it difficult to imagine what they would do.

What exactly does a tap mean? Are these wires that one needs to solder onto a jack? I'd love to have flexibility to use the Champ 600 as a head so 4/8/16 Ohm outputs seems like a great idea. Is it possible to have all three readily available?

[tunghaichuan***]

I'd love to hear more about how OT's affect the sound. I have no experience & find it difficult to imagine what they would do.

Basically all an OT does is convert a high voltage, high impedance, low current signal into a low voltage, low impedance, high current signal that can drive a loud speaker. It is an interface between the high impedance tubes and the low impedance loud speaker. An OT is basically two coils of wire. An AC signal across one of the coils superimposes itself on the second. The primary connects to the tube(s) anode(s). The secondary connects to the speaker.

Generally a specific tube likes to "see" a specific primary impedance, or impedance range. It is a trade off between maximum power out (which most guitar amps go for) and lowest distortion (which most tube hifi goes for). 6V6s in single ended operation, like your Champ 600, work well from 5K to 7.5K.

Single Ended EL84 circuits like about 4K-5K. The original Valve Junior OT was 7.5K and it sounded terrible in that circuit. The new VJ OTs are 5.2K and sound *much* better.

Physical size is also a factor. The Hammond 125ESE, which is about 4 times the size of the stock VJ OT sounds much better than the stock OT. The highs and lows are much smoother. Which brings us to physical construction. The better the materials used in an OT, the better it sounds.

What exactly does a tap mean? Are these wires that one needs to solder onto a jack? I'd love to have flexibility to use the Champ 600 as a head so 4/8/16 Ohm outputs seems like a great idea. Is it possible to have all three readily available?

Taps can be either on the primary or secondary. The primary and secondary are merely long coils of insulated wire. A tap refers to a connection of another wire somewhere along its length. Usually a tap on the primary (tube side of the circuit) is an ultra linear tap, which is mostly used in hifi circuits, but has been used in a few guitar circuits, notably some early 70s Fenders and the Dr Z Route 66.

Taps on the secondary are for interfacing with 4, 8, & 16 ohm speaker loads.

Your Champ has one speaker out jack, no? I'm not sure if there is enough room to add two more jacks or not, you'll have to check. Another option is that you might be able to shoehorn an impedance selector switch into the amp so you can have a selectable impedance out, a la Marshall. My personal preference is to have three separate jacks as there is no switch to fail.

I really need to save up some cash and buy either the Champ 600, or the Gretsch G5222 which is the same amp with different cosmetics.

tung

[tot_Ou_tard]

Your Champ has one speaker out jack, no? I'm not sure if there is enough room to add two more jacks or not, you'll have to check. Another option is that you might be able to shoehorn an impedance selector switch into the amp so you can have a selectable impedance out, a la Marshall. My personal preference is to have three separate jacks as there is no switch to fail.

tung

It's fantastic to have you back tung!

Yes, it has one speaker out jack. Maybe I should wait until I have a cab to change the OT.

Does a beefier OT make the amp louder? I don't really want it to be louder. The volume works very well for me.

[tunghaichuan***]

It's fantastic to have you back tung!

Thanks, good to be back.

Yes, it has one speaker out jack. Maybe I should wait until I have a cab to change the OT.

If the OT you get is much taller than the stock OT, that may be a good plan. It looks like the speaker magnet is fairly close to the top of the OT.

Does a beefier OT make the amp louder? I don't really want it to be louder. The volume works very well for me.

Theoretically, no. The power tube and speaker's sensitivity rating determine how loud the amp is. Having said that, you may get more perceived loudness due to the extended highs and lows of the beefier OT. But again, the speaker can only reproduce sound in its bandwidth. You're not going to get thunderous lows out of a 6" speakers.

BTW, the speaker really is a limiting factor in bass response. I used to run a Silverface Champ into a 4 ohm 4X12" cab and had no problems getting massive amounts of bass out of that little 5W circuit.

I did a quick check on the net and found that the Eminence Alpha 6A is a 6", 8 ohm speaker. It has a sensitivity rating of 93 which is a lot less than the 97-100 of most speakers. It is also rated at 100 watts I wonder if it would fit in that cabinet?

tung