Buzz Posted July 21, 2007 Share Posted July 21, 2007 This is just something that's puzzling me slightly, but is it possible to run say something like a Sound City 120 (120w of valve goodnes) as they're lowish wattage, and run it through a poweramp to beef up the output? I'm just really curious if it's possible or if it would destroy the power amp (or amp infact)? *Not that I intend to do it ofc* Quote Link to comment Share on other sites More sharing options...
obbm Posted July 21, 2007 Share Posted July 21, 2007 [quote name='Buzz' post='35355' date='Jul 21 2007, 07:36 PM']This is just something that's puzzling me slightly, but is it possible to run say something like a Sound City 120 (120w of valve goodnes) as they're lowish wattage, and run it through a poweramp to beef up the output? I'm just really curious if it's possible or if it would destroy the power amp (or amp infact)? *Not that I intend to do it ofc*[/quote] A Sound City 120 is both a pre-amp and a power amp. You can't feed a power amp input from another power amp's output. You could however talke the Sound City pre-amp output from the effects send jack and use a separate more powerful solid-state power amp to drive the speakers. It would however be a criminal waste of a Sound City. Just buy an all-valve pre-amp to drive your power amp. Quote Link to comment Share on other sites More sharing options...
Vasquez Rich Posted July 21, 2007 Share Posted July 21, 2007 (edited) [quote name='Buzz' post='35355' date='Jul 21 2007, 07:36 PM']This is just something that's puzzling me slightly, but is it possible to run say something like a Sound City 120 (120w of valve goodnes) as they're lowish wattage, and run it through a poweramp to beef up the output? I'm just really curious if it's possible or if it would destroy the power amp (or amp infact)? *Not that I intend to do it ofc*[/quote] Only if you have a "line out" or some such output from the first amp, that is using it as a pre-amp stage only. Do not attempt to run a "speaker out" line into the input of another amplifier. Amps work in two stages, pre-amp (usually where the tone shaping and general "sound" comes from) and then the power amp, which boosts the signal to drive the speakers. Only by substituting the external power amp for the internal one (by by-passing it physically) can you do what you are suggesting. Most modern amps have a "line out", that is, line level signal output socket from the preamp so that you can input this into another power amp to drive more speakers, that's how you get stacks of Marshall speaker cabs running together when you play Wembley Arena! Richard Sorry for bit of duplication "obbm" posted while I was cogitating! Edited July 21, 2007 by Vasquez Rich Quote Link to comment Share on other sites More sharing options...
Buzz Posted July 21, 2007 Author Share Posted July 21, 2007 Right, I follow. And just for future reference, I'm well aware of what an amp head like the soundcity is (which was just an example), a pre and power amp in one neat package rather than a split combination. I was just wondering if it was possible, which the answer is no, because I concur, no point having both a valve pre and power if you only intend to use the pre as they both contribute to the final sound. Quote Link to comment Share on other sites More sharing options...
therealting Posted July 22, 2007 Share Posted July 22, 2007 You could use a dummy load device such as a THD Hotplate or a Sequis Motherload to act as a "speaker" for the amp, and take a line out from that. This way, you get the full benefits of pre and power tube colouration. Quote Link to comment Share on other sites More sharing options...
bass_ferret Posted July 22, 2007 Share Posted July 22, 2007 [quote name='Buzz' post='35374' date='Jul 21 2007, 09:00 PM']And just for future reference, I'm well aware of what an amp head like the soundcity is (which was just an example), a pre and power amp in one neat package rather than a split combination.[/quote] Why ask such a dumb question then? Quote Link to comment Share on other sites More sharing options...
obbm Posted July 22, 2007 Share Posted July 22, 2007 [quote name='bass_ferret' post='35486' date='Jul 22 2007, 10:47 AM']Why ask such a dumb question then?[/quote] Quote Link to comment Share on other sites More sharing options...
Dood Posted July 22, 2007 Share Posted July 22, 2007 [quote name='bass_ferret' post='35486' date='Jul 22 2007, 10:47 AM']Why ask such a dumb question then?[/quote] Not dumb, I'd hazard a guess. Some people know about preamps and poweramps, but may not realise that the input of an amp simply cant take the level of signal from a power amp output? Quote Link to comment Share on other sites More sharing options...
Buzz Posted July 22, 2007 Author Share Posted July 22, 2007 [quote name='dood' post='35499' date='Jul 22 2007, 11:37 AM']Not dumb, I'd hazard a guess. Some people know about preamps and poweramps, but may not realise that the input of an amp simply cant take the level of signal from a power amp output?[/quote] ^^ That. Nowhere does it say in the all encompassing stickies that it's not possible to feed an amp into another poweramp to get more wattage, nor does it say why, although I'd hazard a guess it's because it's only designed to take the level of input for a guitar or pre-amp, rather than the more powerful signal of after the poweramp. Although it's nice to know when posing a question you get looked down upon because of your lack of knowledge in a subject. Cheers folks. Quote Link to comment Share on other sites More sharing options...
The Funk Posted July 22, 2007 Share Posted July 22, 2007 Yeah, I think an apology's in order here. It's actually a very sensible question. Some valve amp heads have a line-out stage after the power amp section, eg. Matamp Mini-Mat. My Warwick Quadruplet preamp has a preamp stage AND a power amp valve on a dummy load so that you can get the preamp/power amp valve sound going into a solid state power amp. Imagine if the question had been: "What have I done wrong? My vintage valve head blew up during a gig?" Quote Link to comment Share on other sites More sharing options...
NJW Posted July 22, 2007 Share Posted July 22, 2007 [quote name='Buzz' post='35661' date='Jul 22 2007, 07:34 PM']^^ That. Nowhere does it say in the all encompassing stickies that it's not possible to feed an amp into another poweramp to get more wattage, nor does it say why, although I'd hazard a guess it's because it's only designed to take the level of input for a guitar or pre-amp, rather than the more powerful signal of after the poweramp. Although it's nice to know when posing a question you get looked down upon because of your lack of knowledge in a subject. Cheers folks.[/quote] True. A quick way to learn, and not one that I recommend in ANY WAY WHATSOEVER, is to plug a lead into your guitar, and the other end of the lead in your mouth. Play the guitar, you won't feel a thing. Then plug a lead into the speaker output and put the other end of the lead in your mouth. Warning: This may hurt, a lot. DISCLAIMER: DONT EVER PUT POWER AMP OUTPUTS INTO YOUR MOUTH OR ANY OTHER PART OF YOUR BODY. But yeah - a power amps output is a powerful electrical signal. Plugging it into anything but a cab which is designed to turn these signals into sound, is a bad idea and a surefire way to cause damage for the reasons above. Quote Link to comment Share on other sites More sharing options...
bass_ferret Posted July 22, 2007 Share Posted July 22, 2007 Look at the context of my post. I dont mind people posing dumb questions and I quess we need to update the wiki to state the bleeding obvious, it was the response to the answers that I objected to. Quote Link to comment Share on other sites More sharing options...
Buzz Posted July 22, 2007 Author Share Posted July 22, 2007 (edited) [quote name='bass_ferret' post='35738' date='Jul 22 2007, 10:40 PM']Look at the context of my post. I dont mind people posing dumb questions and I quess we need to update the wiki to state the bleeding obvious, it was the response to the answers that I objected to.[/quote] The answers which wern't any of your posts. And the fact people assumed that I didn't know the difference between a pre/power and a head I thought I'd make it noted that I did know the difference. Then again if the way I informed people of my knowledge so I could get a proper answer offended you I apologize. But at least I don't insinuate the poster is an idiot in a thread I havn't posted in before. To everyone else that's helped, thank you muchly. Edited July 22, 2007 by Buzz Quote Link to comment Share on other sites More sharing options...
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