What kind of AMP and how many watts ?

[JacksonMIA]

Re: What kind of AMP and how many watts ?

I saw this on another forum and thought it might be applicable in this discussion. It's pretty accurate.

I'll give you the obligatory speech about watts VS. volume so that you don't get all caught up in the 100+ watts thing.
The way that watts translate into decibels is in powers of 10. That being the case, if you want to do twice as loud, you need to go 10x higher in wattage. The difference in volume between 100W and 50W is actually only 12% less or so. HALF the volume of 100W is actually 10 watts, and TWICE the volume of 100w is actually 1,000 Watts. And when is the last time you played a 100W amp on a setting higher then 3 on the volume without everyone screaming to turn it down!

Now, after you have digested that, we can move along to the next part.

Speaker efficiency is also key to volume. That curve is also not linear. If you take 2 otherwise identical speakers, one with a sensitivity rating of 103dB, and one with a rating of 100dB, that -3dB drop is the equivalent of sending half the power into the speakers... like moving from a 100W amp to a 50W amp, of about a 12% drop in power.

Now, if you move from the 103dB speaker to a 97dB speaker that is otherwise identical, that -6dB drop is like moving from a 100W amp to a 25W amp. That being the case, a 25W amp played through 103dB speakers is exactly as loud as a 100W amp being played through 97dB speakers.

OK, digest that for a second and then we'll move on.

Last week, I played a 35W amp on full blast (but not clipping) through a Marshall 4x12" cabinet loaded with Celestion Vintage 30's, which have a sensitivity of 100dB. I took out a sound pressure level meter and put it 10 feet away from the speakers. The 35W amp produced a clean power level of 117dB, which is only 3dB quieter than an airplane landing.

With all that in mind, you should decide on whether you really want to go with the added expense, weight, maintenance and extra wiring that a 100w amp requires.

 

[some_dude]

Re: What kind of AMP and how many watts ?

I saw this on another forum and thought it might be applicable in this discussion. It's pretty accurate.

Although I agree with everything he says, I've run out of headroom on a 100w amp into a 4x12 loaded with V30s.

Not everyone is playing blues gigs with little bass and the mids dimed.....if you don't want your bottom end to tub out, you're going to want the headroom.

 

[JacksonMIA]

Re: What kind of AMP and how many watts ?

Although I agree with everything he says, I've run out of headroom on a 100w amp into a 4x12 loaded with V30s.

Not everyone is playing blues gigs with little bass and the mids dimed.....if you don't want your bottom end to tub out, you're going to want the headroom.

Definitely. There are a lot of other factors to consider. Even something that seems so negligible like cabinet design can have a huge influence - especially at high volumes.

I haven't played live enough to share any experiences, though. Those guys are the ones to really listen to.

 

[Lake Placid Blues]

Re: What kind of AMP and how many watts ?

Just to simplfy, he probably needs an all tube, 50 watt amp. It doesn't really matter if the brand name is Fender, Marshall, or Mesa. A 2x12 speaker arrangement is fine, be it a seperate cab, or in a combo.

I have always got by gigging with a 50 watt tube amp. In one band, we had a brutally hard hitting drummer, and a 50 watt Marshall could still handle it, with out mic'ing up. That was one loud rock band. Turned up to about 7, I had plenty of power and was right in the sweet spot, were I could get both good cleans and overdrives. I should point out that I usually ran V30's at the time.

Mic'ing up is a much different experiance, and if a 50 watt doesn't have the head room, then it's probably a mic'ing situation anyway. They usually want you to be limited in loudness, so that your stage volume doesn't bleed into other instrument or vocal mic's. One time they mic'ed me up in a large venue, and the sound man kept telling me to turn it down during the sound check, to the point, that I was on 3 or 4. I was running it in triode mode, or 1/2 power too. Not much chance for power tube tone there at all. I should have been using a champ.

 

[Grungy_AJ]

Re: What kind of AMP and how many watts ?

Just to simplfy, he probably needs an all tube, 50 watt amp. It doesn't really matter if the brand name is Fender, Marshall, or Mesa. A 2x12 speaker arrangement is fine, be it a seperate cab, or in a combo.

I think you are right, everyone is suggesting that i go along with 50watts tube amp, so i guess i am going to look around for that now, but somebody mentioned SilverFace or BlackFace fender, i have been hearing this recommendation by lots of people, i tried looking up reviews for it, but i didn't find much... Anyone knows anything about it ? and really thanks for the advices so far, its been helpful ! Not to mention that whole WATT VS. VOLUME thoery... Right on ! :arms:

 

[Lake Placid Blues]

Re: What kind of AMP and how many watts ?

The early 60's Fender amps had black control panels. This is were the black face designation comes from. There were two basic high power circuts and several amp models that were derivatives of these.

The 80 watt circut (actually 100 imo) used four 6L6 power tubes. The Twin Reverb was a 80 watt 2x12 combo. The Dual Showman was a 80 watt head.

The 50 watt circut used two 6L6 power tubes. The main diffrences were the speaker configurations, and add on features like reverb. Combo models were the Super, Vibroverb, Pro.... and so forth. The Bassman was a 50 watt head. I have used a SF bassman (converted to BF specs) many times. It's a very versatile 50 watt head. It starts to distort at about 5-6 with the volume on your guitar dimed. It's a great output stage distortion too. You can go cleaner by rolling back your guitar volume a little bit, or Fender clean by turning the amp volume down a bit.

After Leo Fender sold the company to CBS they changed the control panal color to silver. These are the SF amps. CBS messed with the circuts, but they can be converted back to BF specs fairly easy. I found a SF bassman head in pawn shop for $90 back in the early 90's. These amps have point to point wiring, and are very well built compared to modern amps, but they don't have high gain channels, and channel switching, and other modern features...

On edit: SF amps are really not easy to find for sale anymore, cheap or expensive..BF amps are expensive if you find a seller...