Can you change your amps output transformer to make it lower wattage?

[Cory_Dylan]

For playing in the bedroom, I need a really low wattage amp. (I mean really low)

I was just looking into pro juniors just for the hell of it, (not buying one), and I saw one on ebay that said the output transformer has been upgraded to an 18 watt one.

And I was thinking, would I be able to do that to my classic 30 and make it less wattage? I'd like to be able to crank it.

Just a thought.

 

[That90'sGuy]

Re: Can you change your amps output transformer to make it lower wattage?

I'd check the specifications of the transformer very carefully. You could, in theory, get a step down transformer that takes in the same amount of line voltage, and puts out less voltage, but the rest of the circuit would probably have to be tweaked accordingly. The tubes would have to be completely rebiased as well and since they wouldn't be pushed as hard, I would imagine it wouldn't sound as good. That's my best guess (given my limited knowledge of transformers).

 

[Cory_Dylan]

Re: Can you change your amps output transformer to make it lower wattage?

Hmm, well I guess it won't work then.

What I was hoping to do was be able to get cranked tube tone without it having to be as loud.

Anyway to do this without a power attenuator?

 

[skyydogg01]

Re: Can you change your amps output transformer to make it lower wattage?

go here:

http://namm.harmony-central.com/WNAMM05/Content/Groove_Tubes/PR/Power-Reducer.html

ok, i just realized you had an 18 watt amp so this product will do you no good.

 

[Jag513]

Re: Can you change your amps output transformer to make it lower wattage?

^He doesn't have an 18 watt amp; he saw one on eBay. He has a 30 watt amp.

The reason it won't work though is that the C30 already runs EL84's!

the_Chris is right. You'd have to tweak the rest of the amp to run a lower wattage tranny.

A power attenuator would be a great solution. You'd lose some tone, but not that much.

 

[Quencho092]

Re: Can you change your amps output transformer to make it lower wattage?

how does upping to a higher output tranny affect the circuit?

 

[Jag513]

Re: Can you change your amps output transformer to make it lower wattage?

Well upping to a higher wattage tranny wouldn't, as long as it could take the same voltage. But going to a lower wattage tranny would require modifications to not bust the tranny. You could lower it to a certain point and just get breakup earlier (the output transformer actually is a part of power amp breakup), but beyond a certain point it'd just blow the tranny. I'd assume that if the thread starter wanted to get power amp breakup at lower volumes, less than 10 watts would be good (any more watts and it'd be just a little bit quieter). You'd need to modify the circuit and bias the tubes to a very small plate dissapation to achieve that.

However, Corey, since there are 4 EL84's, you could just remove the outer pair and run at half wattage. It'd only provide a 3dB difference though, and it would create a slight impedance mismatch.

 

[Mkf411]

Re: Can you change your amps output transformer to make it lower wattage?

Depending on your situation, even most 5 watt amps cranked in an apartment will be noticed by your neighbors. I am of the opinion that cranked tube amp tone at low volumes isn't possible. I'd love to be proven wrong. But according to amptone.com, a 10th of a watt would be enough power for home use. So for a 30 watt amp, an attenuator will get you the closest, but part of cranked amp tone is pushing the speaker and that won't be happening with lots of attenuation. I'm thinking a good pedal would be alternative. If I didn't have a good overdrive, I'd ask around for the best pedal for my amp and try some out. Smaller less effecient speakers will also help reduce overall volume according to amptone.com

Pedals are a cheaper solution and if you find the right one for your style and amp, you'll probably be happy.

 

[Lewguitar]

Re: Can you change your amps output transformer to make it lower wattage?

Just get a Mass from Weber VST...it'll let your amp do exactly what you want. Lew

 

[Cory_Dylan]

Re: Can you change your amps output transformer to make it lower wattage?

Thanks guys, I appreciate it.

Damn, being quiet is really a pain in the ass... I guess I'm just going to have to learn to be loud... maybe a part of this has to do with my room being 9' X 10', so I have to be about 5 feet away from the amp minimum. I'll figure something out.

I'll do some reading on that amptone.com.

 

[suislidE03]

Re: Can you change your amps output transformer to make it lower wattage?

Wow i just went to the weber site and looked at the mass, its only $140 for a 50Watter. Thats not bad.. plus by reading the overview it sounds alot more convincing and effecient. Anyone have one and care to share their opinion?

 

[Cory_Dylan]

Re: Can you change your amps output transformer to make it lower wattage?

Funny, the clips for the MASS are by Stevo...

Thanks, I'm gonna get one of these. The only reason I didn't want an attenuator was becuase i thought they were really expensive.

What do I need? 15 watts into 16 ohms?

 

[suislidE03]

Re: Can you change your amps output transformer to make it lower wattage?

yea i think i will really consider getting a 50 watt for my laney, cause its just too damn loud. Would be nice if the thing came with an extra speaker cable.. (why not?)

 

[Mkf411]

Re: Can you change your amps output transformer to make it lower wattage?

Funny, the clips for the MASS are by Stevo...

Thanks, I'm gonna get one of these. The only reason I didn't want an attenuator was becuase i thought they were really expensive.

What do I need? 15 watts into 16 ohms?

I'm pretty sure you need one that matches or exceeds the watts on your amp and matches the ohms of your speaker. Webers models that I've seen recently on their site have 4,8,16 ohm switch. I would call them and discuss the amp you have and your situation and see which model they suggest. Good luck

 

[bert123]

Re: Can you change your amps output transformer to make it lower wattage?

I've investigated using attenuators on my Classic 30. The 'speaker out' does NOT disconnect the internal speaker thus I would have needed to put the attenuator in the cabinet between the output transformer and the speaker.