Using solid-state amplifier as a extension cab.

[homelife88]

A few days ago I had the idea of plugging my Champ 600 into my larger Fender solid-state amp to get a bit more volume out of it. I didn't actually try it out yet, I just kind of wanted to find out if this is a good idea. I've done a little research and talked to a friend of mine about the idea...I'm by no means an expert when it comes to things like this. Could anyone help me out?

 

[tunghaichuan]

Since the Champ 600 doesn't have a line out, the only way you can connect it to the SS amp is to plug the speaker out into your amp.

DON'T DO THIS! Sorry for the caps, but you risk damaging your Champ and the SS amp.

What you have to do is make a line out circuit to add to your amp:

http://www.netads.com/~meo/Guitar/Amps/Kalamazoo/Mods/ezlo.html

But you must keep a speaker plugged in.

You can also use a cabinet simulator box like the Behringer GI100:

http://www.behringer.com/EN/Products/GI100.aspx

This has a line out circuit and also a speaker emulator circuit. But again, you'll need to have a speaker connected.

BTW, don't be shy, stop by the Fret Players forum and introduce yourself, this is a great group of people.

tung

A few days ago I had the idea of plugging my Champ 600 into my larger Fender solid-state amp to get a bit more volume out of it. I didn't actually try it out yet, I just kind of wanted to find out if this is a good idea. I've done a little research and talked to a friend of mine about the idea...I'm by no means an expert when it comes to things like this. Could anyone help me out?

 

[aeolian]

Tung, thank you for your explanation. Lately I been wondering about the difference between line out and speaker out; is it basically load and current and power dissipation?

Is there a way to split my guitar output using some sort of splitter and then plugging into both amps. I know people use more than one amp at the same time, I just don't know how they set it up.

 

[homelife88]

Thanks Tung! I was afraid to try it w/o getting some advice first. It seems like it would be a killer way to get more volume out of my Champ. I will probably add a line out...

 

[tunghaichuan]

Tung, thank you for your explanation. Lately I been wondering about the difference between line out and speaker out; is it basically load and current and power dissipation?

Basically, there are a few types of line out circuits. The most common are the preamp out line out and the post output transformer line out. Preamp line outs take their signal from the end of the preamp. These generally don't sound good on low gain amps due to the fact that most of the distortion comes from the power tube/output tranformer/speaker. But for amps like the Soldano SLO, Boogie Rectifier, or Peavey 5150, where most of the tone is generated by the preamp, this type of circuit can sound very good.

The post OT line out takes the output from the output transformer, and uses a voltage divider, which cuts the output down to preamp levels where the input of another amp can handle it. An OT puts out several watts of power in a Champ-style circuit. This can sound very good because you are using the power tube and transformer to influence the tone. However, the speaker is not in the loop. That's why I suggested the Behringer GI100, it EQ's the signal to give it a 4x12" guitar cab sound. Hughes and Kettner makes the Red Box which is basically the same, but ads a combo EQ setting. However the Red Box is about 4X the price of the Behringer.

Also, the post OT line out still needs to have some kind of load attached to the output transformer, either a speaker, or a dummy load made of resistors to keep the OT happy. The output of the OT wants to see a minimum impedance of about 4-16 ohms depending on how it is wound. The input of a solid state amp can be around 10k-50k ohms. The input of a tube amp is around 500k to 10 meg ohms. These input impedances are way to high for the OT and will result in damage to both amps.

Is there a way to split my guitar output using some sort of splitter and then plugging into both amps. I know people use more than one amp at the same time, I just don't know how they set it up.

This seems to be the best option:

http://www.whirlwindusa.com/selec.html

You can select either amp or both at the same time. If you plug into both amps using a Y cord, you can get ground loop problems.

tung

 

[tunghaichuan]

Thanks Tung! I was afraid to try it w/o getting some advice first. It seems like it would be a killer way to get more volume out of my Champ. I will probably add a line out...

Glad to help out, I didn't want you to damage your equipment.

You can make a box to plug into the output of your Champ 600 with the voltage divider line out. You can also put a 10W 4 ohm resistor in the circuit to load down the OT so that you don't have to use the speaker.

tung

 

[Brian Krashpad]

This seems to be the best option:

http://www.whirlwindusa.com/selec.html

You can select either amp or both at the same time. If you plug into both amps using a Y cord, you can get ground loop problems.

tung

Ah, yes, the ol' A/B, or rather ABY pedal. I have Morley's version:

http://www.zzounds.com/item--MLYABY

All my amps are relatively big, so I've never actually really used it.

:thwap:

 

[tunghaichuan]

An even better choice at half the price of the Whirlwind. Thanks for posting that Krash. :AOK:

tung

Ah, yes, the ol' A/B, or rather ABY pedal. I have Morley's version:

http://www.zzounds.com/item--MLYABY

All my amps are relatively big, so I've never actually really used it.

:thwap:

 

[homelife88]

Glad to help out, I didn't want you to damage your equipment.

You can make a box to plug into the output of your Champ 600 with the voltage divider line out. You can also put a 10W 4 ohm resistor in the circuit to load down the OT so that you don't have to use the speaker.

tung

So do you know of a box that I could place between the the Champ speaker output and the SS amp to take the power load down to a safe level? I got on the Radial Engineering website to see what they have, but I'm not entirely sure what I'm looking for or if it even exists. It seems like that would be the easiest fix.

It would also be nice to not have to use the speaker in my Champ.

 

[Ch0jin]

Maybe I've missed something, but wouldn't the first option be to try using the champ to power the SS amps speaker/s? That's got to be the easiest and less risky option to get more volume assuming impedance's match.

Basically I'm saying use the larger SS amp as an extension cab. If that doesn't give you enough sound then I'm thinking bigger amp or get some pedals for that SS amp and just use it instead

 

[just strum]

Good info Tung, you probably saved someone here from damaging some gear.

 

[tunghaichuan]

You could use this box:

https://taweber.powweb.com/weber/micromass.htm

Turn the attenuation all the way up and you don't need a speaker. It has a line out to pad the output of your amp down to a safe level. It also uses a speaker voice coil to simulate a speaker.

However, Ch0jin has a good point, if possible you could hook up the speaker of the SS amp to the Champ 600. The impedance should match, though. The Champ 600 has a 4 ohm speaker in it. What is the impedance of the SS amp's speaker(s)?

tung

So do you know of a box that I could place between the the Champ speaker output and the SS amp to take the power load down to a safe level? I got on the Radial Engineering website to see what they have, but I'm not entirely sure what I'm looking for or if it even exists. It seems like that would be the easiest fix.

It would also be nice to not have to use the speaker in my Champ.

 

[homelife88]

You could use this box:

https://taweber.powweb.com/weber/micromass.htm

Turn the attenuation all the way up and you don't need a speaker. It has a line out to pad the output of your amp down to a safe level. It also uses a speaker voice coil to simulate a speaker.

However, Ch0jin has a good point, if possible you could hook up the speaker of the SS amp to the Champ 600. The impedance should match, though. The Champ 600 has a 4 ohm speaker in it. What is the impedance of the SS amp's speaker(s)?

tung

The SS speaker is rated at 8 ohms. The thing is no matter how big the speaker is on the amp, I'm still only going to have 5 watts coming out of the Champ. Just hooking the speaker up to the Champ will make it louder and give me less speaker breakup, but it won't give me any more headroom. That's what I was looking for out of the setup, being able to control gain w/ the Champ volume and controling overall volume w/ the SS amp. So basically I want to be able to get a nice volume while keeping the Champ clean if possible.

 

[tunghaichuan]

Okay, gotcha. I would look into building a line out box using the link above. It should cost you around $10US including the jacks, the enclosure and the resistors.

If you want to spend a little more, the Weber MiniMass might be the way to go although it is made for cranking up the amp and getting distortion at low volumes.

Since you want more clean headroom, I'd suggest you try a 5751 or 12AY7 preamp tube instead of the 12AX7 in the Champ.

tung

The SS speaker is rated at 8 ohms. The thing is no matter how big the speaker is on the amp, I'm still only going to have 5 watts coming out of the Champ. Just hooking the speaker up to the Champ will make it louder and give me less speaker breakup, but it won't give me any more headroom. That's what I was looking for out of the setup, being able to control gain w/ the Champ volume and controling overall volume w/ the SS amp. So basically I want to be able to get a nice volume while keeping the Champ clean if possible.