Help me choose a speaker for my Champ...

[mcinku]

Haaa, this took forever but now it's finally done...


at the end I bought P10Q Jensen and I like it.

[Konny]

That´s a nice Champ!

How did you do the writing on the chassis?
I´ve used waterslide decals for mine, worked good but not perfect.

Have you ever measured your bias?
On my Champ the bias is way too high (46mA @ 350V Ua)

Swen

[mcinku]

That´s a nice Champ!

How did you do the writing on the chassis?
I´ve used waterslide decals for mine, worked good but not perfect.

Have you ever measured your bias?
On my Champ the bias is way too high (46mA @ 350V Ua)

Swen

Thanks,
I used some stickers, which I printed out with some P-touch electronic labeler. I hate it, but that all I can do without a proper faceplate. I'm thinking about getting a proper faceplate.

No, I didn't measure the bias.

[Konny]

Okay. If you measure it let me know.

What do you think about the Jensen?
I use a Jensen C8R and I´m not sure If I should keep it...at higher Volumes it sounds strange somehow.

[mcinku]

Okay. If you measure it let me know.

What do you think about the Jensen?
I use a Jensen C8R and I´m not sure If I should keep it...at higher Volumes it sounds strange somehow.

I like it very much. The bass response is not as big as with 12" but the hi end is awesome. Very sparkly without getting harsh.
In fact, if this amp would have 10 more watts I would probably sell my DRRI.

One of my main reasons why I started this Champ project, is to be able to use at least 10" speaker. Anything less than that is no go for me. I'm yet to hear a small speaker that I like.

Overall I'm happy with my choice.

[Jag]

Konny, what's the value of the cathode resistor on your output tube?

How are the waterslide decals holding up? Did you use a clear coat over them to add to the durability?

Nice job Mcinku! I'm with you, an 8" speaker doesn't generally do it for me. A floating baffle helps alot though.

[Konny]

I tryed the 470 ohms on catode as in the fender schematic.
due to higher U+ my 6V6 takes something around 15Watts with this cathoderesistor.
I´ll drop the U+ and then go for 1k I think. Then the 6V6 will have around 8Watts plate dissipation.

The waterslide decals are really really cool. I´ve clear coated them 5-6 times and now they are very durable and in addition not recognizable.

But see yourself . . .






Perhaps I´m gonna do an additional speakerbox for the Champ, 1x12 or even 2x10, we´ll see.

Swen

[Jag]

Thanks for the pics and info Konny.

Actually, the reason I asked about the cathode resistor was because I thought it might be low. Around my neck of the woods (Western Canada) a 1K usually works best in a 6V6 Champ style clone. This is not a rule but just where I sort of start, then I tweak.

[Konny]

Yes, I think 470 is to low, it seems that something around 1k works fine.

I´m still finetuning...I think I´ll lower Ua to 358V and put a 1k on the cathode. This will get me around 8Watts which I believe is good for a Champclone.

I´ll keep you updated.

[mcinku]

You have a nice looking Champ Konny I like it.

The idea about an additional speakerbox is a good one.
I have a Greenback cab and it sounds awesome with my Champ.

[tubeboy]

Nice looking amp, is that a 6v6 or a KT88?

Chris

I tryed the 470 ohms on catode as in the fender schematic.
due to higher U+ my 6V6 takes something around 15Watts with this cathoderesistor.
I´ll drop the U+ and then go for 1k I think. Then the 6V6 will have around 8Watts plate dissipation.

The waterslide decals are really really cool. I´ve clear coated them 5-6 times and now they are very durable and in addition not recognizable.

But see yourself . . .






Perhaps I´m gonna do an additional speakerbox for the Champ, 1x12 or even 2x10, we´ll see.

Swen

[Konny]

Hi Chris,

in this pic there is a KT88.
I´ve installed a switch for cathode resistors so I can go for around 8W with the 6V6 or for 13-15W with 6L6 or KT88 Co.

This option is pretty cool. You can play at home at low volumes and when power is needed you just plug the KT in and have a lot more power.

Swen

[mcinku]

Hi Chris,

in this pic there is a KT88.
I´ve installed a switch for cathode resistors so I can go for around 8W with the 6V6 or for 13-15W with 6L6 or KT88 Co.

This option is pretty cool. You can play at home at low volumes and when power is needed you just plug the KT in and have a lot more power.

Swen

Swen, do you have a gut picture of your Champ. I would like to see how you installed the two cathode resistor thing.
I like the sound of my Champ so much that I wouldn't mind having a few more Watts (to keep up with a drummer).

[mcinku]

OK during this weekend I opened my Champ and installed the additional 6L6 cathode resistor. I used 390ohm 5W resistor, this is all I could find at the moment.
Accordingly to Nik I could use even smaller value resistor for some more power.
At the moment the power boost is not huge but it's noticeable.

It's not pretty but it works. (sorry for a bad phone pic)

[Konny]

Sorry guys, I forgot posting a pic

I did it nearly the same way so that´s fine I think.

Do you switch the 390 in parallel with the 470 or do you switch between those resistors?

I wouldn´t go below something around 250Ohms, remember that your grid needs to be negativ to the cathode. So with lowering the cathoderesistor you also lower the grid-cathode-voltage and perhaps you´ll get "blocking distortion"!? (don´t know if this is the correct english term )

I think you only notice a small difference because the 6V6 is driven quite hot with 470 Ohms on the cathode.
I have 1k at the cathode and my Ua is around 360V......you should have a lot more Ua and also an extremely higher current with your 6V6.

Here´s a pic of my Champ....but remember, it´s not finisghed, I´m still testing and tweaking as you can see at the socket of the 6V6 and the power supply
http://www.bilder-hochladen.net/files/3rax-o-jpg.html

swen