Guitar Questions

[Rick Lee]

IROC, I think you're talking about headroom. But the opposite is also true. A lot of folks like the breakup distortion sound, which, in a lot of tube amps, doesn't sound right until there's some serious volume, the tubes are bright orange and the cabinet speakers are really moving air.

[Les Paul]

Back in the day I put together a volume box for a Fender HRD. 15 dollars in parts and worked great still have the plans for you fender tube amp fans if interested. Turn it up to 10 those tubes starting glowing and rock on.

[Cajundaddy]

Originally Posted by IROC

IIRC, a decibel is defined as the sound level produced by 1 watt of power at 1 meter. Most guitar amp speakers have a "sensitivity" of around 96 to 100 dB, so that means that they produce 96 to 100 decibels of sound per watt of input power.

So...it becomes obvious really quickly that it doesn't take a lot of power input to create a lot of decibel output. Many people are concerned with keeping the guitar sound clean at higher volumes, so that requires a decent amount of wattage. Basically, though, 10 watts can be really, really loud. Also, it takes 10 times the power input to double the volume output, so a 100 watt amp isn't 10 times louder than a 10 watt amp - it's only twice as loud.

Car speakers are generally rated as "power handling capability", which has nothing to do with how loud they are.

All the above is from memory which is probably wrong/urban legends, so feel to correct any errors.

Pretty close actually. Amplifier power's relationship to sound is logarithmic so doubling the power increases the volume 3db. With a 100db/w speaker, 10 watts will give you 110db, 20 watts will give you 113db, 100 watts will give you 120db. For reference, a Rolling Stones concert is usually around 110db.

Car speakers are a bit different. Most have lower sensitivities at around 88db/w, so 10w will deliver 98db, 20w will be 101db, 100w will be 108db, 1000w will be 118db (providing the speaker can actually handle that much current).

Apples and oranges. A guitar amp is a lot louder at any given wattage providing an efficient speaker is used.

[LSA]

Cd beat me to it, yeah it's because sound is on a logarithmic scale. He did a much better job explaining it than I would have though.

I'd really like one of the Jet City heads. Designed by Soldano but not at the Soldano price...

[IROC]

Originally Posted by Cajundaddy

Pretty close actually. Amplifier power's relationship to sound is logarithmic so doubling the power increases the volume 3db. With a 100db/w speaker, 10 watts will give you 110db, 20 watts will give you 113db, 100 watts will give you 120db. For reference, a Rolling Stones concert is usually around 110db.

Thanks for setting me straight. I think I confused decibels with sensitivity. Isn't sensitivity the rated decibel output of the speaker at 1m with an input of 1 watt?

Anybody else tried a Marshall DSL 15? Man, I love that thing...

[IROC]

Originally Posted by LSA

I'd really like one of the Jet City heads. Designed by Soldano but not at the Soldano price...

I thought those were designed by Andy Marshall of THD? I was thinking about a Picovalve there for awhile...

[LSA]

I think the picovalve is but the other jca are based off Soldano's design, I know in an interview he said the jca20 was based off the circuit from the Atomic 16.

[Rick Lee]

I think Jet City is made by Soldano, but in China or Vietnam. I think there's also more than one Jet City company in the music biz, so that confuses it some more. Soldano is made in Seattle and it's about as big and automated as the old Porsche seamstress shop. Serial numbers are hand written and you're just as likely to have Mike Soldano pick up the phone there as someone else. I saw a 200w SLO on eBay a while back, I think for $7k, that was being sold by the Soldano employee, who had built it for himself. He offered a lifetime guarantee, meaning as long as he's alive, he'll fix anything.

[targa911S]

Originally Posted by Cajundaddy

The reality is this is probably all the amp any of us really need. 5 watts of great guitar tone at 106db. If we play Madison Square Garden or Angel Stadium it doesn't matter what amp we bring. They are going to mic it and run it through the house system anyways.

Ding Ding Ding!

[targa911S]

My "go to" bass rig is a 500 watt Ampeg portaflex head and an Ampeg SVT410HLF. My "laptop" unit for small club venues and practice is an Ampeg BA115HP 220 watt combo unit. Both serve me well in most situations. For bigger outdoor stuff my rider says SVT 810 and minimum of 400 watts. Rich hates it when I have that much power. He uses a 40w pignose.

[Cajundaddy]

Originally Posted by IROC

Thanks for setting me straight. I think I confused decibels with sensitivity. Isn't sensitivity the rated decibel output of the speaker at 1m with an input of 1 watt?

Yes. Modern speaker sensitivity is measured as SPL in db @ 1watt, 1 meter. 100db/w is a shorthand sensitivity rating. It assumes 1watt @1m

[Cajundaddy]

Originally Posted by targa911S

My "go to" bass rig is a 500 watt Ampeg portaflex head and an Ampeg SVT410HLF. My "laptop" unit for small club venues and practice is an Ampeg BA115HP 220 watt combo unit. Both serve me well in most situations. For bigger outdoor stuff my rider says SVT 810 and minimum of 400 watts. Rich hates it when I have that much power. He uses a 40w pignose.

Bass is a different animal still. It produces really big fat sound waves that require big fat speakers in big cabinets and lots of power. Our ears also don't perceive bass notes as easily as midrange guitar or voice so they usually need all the juice they can get. I really like that Ampeg 410 cab. Lots of punch and dynamics and pretty efficient.

[nostatic]

Originally Posted by futuresoptions

Did a little searching around last night and found what I think would be a middle ground amp. Not a tube amp and not quite a digital modeling amp. This one is a analog modeling amp. Made in the USA. Color me stupid, but I had never heard of Tech 21 before. Sounds pretty damn good and looks beautiful in a retro kind of way...

I own one of these - only guitar amp I have left in the house. They are much better than modeling imho - they have some "bounce" and you can get some nice sounds out of it. They can often be found dirt cheap on the used market.

[targa911S]

Originally Posted by Cajundaddy

Bass is a different animal still. It produces really big fat sound waves that require big fat speakers in big cabinets and lots of power. Our ears also don't perceive bass notes as easily as midrange guitar or voice so they usually need all the juice they can get. I really like that Ampeg 410 cab. Lots of punch and dynamics and pretty efficient.

Yes I like that cab too. It's like an 810 you left in the dryer too long. NOTHING sounds like 8-10's but I'm 61 and I refuse to drag one around anymore. been there done that for years. But it IS in my rider if somebody else brings it.

[stuartj]

Ditto on the Tech 21 stuff, its great. The only amp i have t home is a little 50w trannie Yamaha, which coupled with a light OD, is absolutely adequate. Its been going strong since 1978. Bets bit of gear Ive ever had.

My bass plyer has just gone from a big-ish rig to a tiny Mark Bass head and cab. It actually sounds pretty good. But as he sends to in-ears and DI to the PA- it doesnt matter....

[Rick V]

I have a Hartke GT100 that uses a one tube pre with an IC slave, sounds the same at any volume. The only thing I found that I am not too thrilled with is the reverb, it doesn't have the depth of say a Fender amp. Hell the reverb in my little 15 watt Fender bullet smokes it.

[campbellcj]

I definitely agree for not overkilling with amps for practice or smallish venues. The VOX AC15 has been working great for me and my son - can practice at home with the master volume way down (like on "1") but still get good tube breakup if you want. Built in reverb and tremolo are sweet too, plus it is not a beast to lug around like the bigger combos or head/cab amps, around 45lbs vs. 70+

[VaSteve]

Originally Posted by Les Paul

40 watts of tube is like 100 watts solid state. Or so it seemed to me.

I bumping this back up. I repaired my SS Princeton Chorus 125W amp for the second time, the pots were dirty and it was cutting out. I bought a little Tube Champ x2 which is rated like 15w. I have taken the champ to band practice many times and it sounds good. I wanted to leave the PC at the other guys house to make the loud in/out easier.

I A/B'ed them today to try and dial the PC in the way I like the other one. Maybe my ears are messed up, or the lack of the rest of the band, but I expected the 125w amp to be a lot louder. I would say that they are "comparable". It's suitable for practice (provided it doesn't flake out again) but I don't think it would measure up for a gig. Even with the bass cranked up, the little amp sounds so much fuller.

So, am I out of my mind or is this a valid or semi valid equation above?

[Cajundaddy]

First, the Princeton Chorus is 25w per ch, not 125w. What you are seeing on the back rating plate is power consumption from the wall, not power output. It is a nice amp for what it does well but I appreciate the sound of a Champ X2 better. I would gig with the Champ but probably not with the PC.

http://support.fender.com/manuals/guitar_amplifiers/Princeton_Chorus_manual.pdf

[targa911S]

I don't get it. Isn't 100 watts 100 watts? I hear it all the time from guys that have the tube classic SVT head that is 300 watts. I have 500 watts in a PF 500 head that is solid state. Are you gonna tell your watts are different than mine?