Dad3353 Posted February 18, 2015 Share Posted February 18, 2015 [quote name='Subthumper' timestamp='1424219754' post='2694121']...Should I make one? If so what do folks want to see feature wise? [/quote] A choice between rosewood and maple cabinet, for 'tonewood' reasons..? Quote Link to comment Share on other sites More sharing options...
Pentode Posted February 18, 2015 Share Posted February 18, 2015 Sorry I don't get all this crap about valve heads overhanging the sides of cabs. The solution's quite obvious as I see it.... Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted February 18, 2015 Share Posted February 18, 2015 [quote name='Pentode' timestamp='1424246486' post='2694188'] Sorry I don't get all this crap about valve heads overhanging the sides of cabs. The solution's quite obvious as I see it.... [/quote] Think of your poor confused electrons! Quote Link to comment Share on other sites More sharing options...
Count Bassy Posted February 18, 2015 Share Posted February 18, 2015 [quote name='JPJ' timestamp='1423672793' post='2687795'] Just a daft question, but as we are told that the 'valve sound' comes from the interaction between the valve preamp and the valve power amp, is it not possible to have say a valve pre driving a low wattage valve power amp driving a class D type amp module with a lightweight switch mode power supply? [/quote] I have a feeling that some of the Blackstar guitar amps do this, but could be wrong. Quote Link to comment Share on other sites More sharing options...
fretmeister Posted February 18, 2015 Share Posted February 18, 2015 [quote name='Count Bassy' timestamp='1424281775' post='2694729'] I have a feeling that some of the Blackstar guitar amps do this, but could be wrong. [/quote] Didn't some Warwick bass heads do that - had a little power valve on the board, and then into the proper SS poweramp? Quote Link to comment Share on other sites More sharing options...
Subthumper Posted February 18, 2015 Share Posted February 18, 2015 Yes, that was on the tubepath heads. Ampeg did a similar thing with the SVT3 except it was a valve driving the mosfet power stage and the valve had an adjustable plate voltage to introduce some form of compression/grit/drive type thing. Quote Link to comment Share on other sites More sharing options...
acidbass Posted February 18, 2015 Share Posted February 18, 2015 I think the only route to lightweight valve sound is valve pre/digital power amp! Quote Link to comment Share on other sites More sharing options...
Musky Posted February 18, 2015 Share Posted February 18, 2015 [quote name='acidbass' timestamp='1424287720' post='2694827'] I think the only route to lightweight valve sound is valve pre/digital power amp! [/quote] SMPS like the VB3? That only weighs in at 37lbs for a 300w amp with a lot of features on the front end. Not genuinely lightweight but a featherweight for a valve amp. Quote Link to comment Share on other sites More sharing options...
wateroftyne Posted February 18, 2015 Share Posted February 18, 2015 [quote name='Subthumper' timestamp='1424283807' post='2694756'] Yes, that was on the tubepath heads. Ampeg did a similar thing with the SVT3 except it was a valve driving the mosfet power stage and the valve had an adjustable plate voltage to introduce some form of compression/grit/drive type thing. [/quote] Yup - the Tubepath is like the MESA Walkabout. It's a different approach to virtually all other hybrids. Nothing will get the valve thing going on like a valve power stage, but the WA gets close for something so compact and light. Quote Link to comment Share on other sites More sharing options...
deepbass5 Posted February 18, 2015 Share Posted February 18, 2015 (edited) This would fit the bill, you lift the top off when playing. not cheap though [url="http://www.cmsme.de/epages/62030644.sf/de_DE/?ObjectPath=/Shops/62030644/Products/%22Rheingold%20B100%22"]http://www.cmsme.de/...ngold%20B100%22[/url] Edited February 18, 2015 by deepbass5 Quote Link to comment Share on other sites More sharing options...
Subthumper Posted February 19, 2015 Share Posted February 19, 2015 Some fantastic German techie words in there. Nearly ordered one by mistake when I thought I was on the translation icon. Not cheap though. Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted February 20, 2015 Share Posted February 20, 2015 [quote name='JapanAxe' timestamp='1423690367' post='2688067'] [size=5]I wondered about basing something on the Carvin Legacy 100W guitar head ([color=#000000][font=Arial, Helvetica, sans-serif]17" wide x [/font][/color][color=#000000][font=Arial, Helvetica, sans-serif]9" deep x [/font][/color][color=#000000][font=Arial, Helvetica, sans-serif]8.5" high, [/font][/color][color=#000000][font=Arial, Helvetica, sans-serif]Weight: 29 lb) [/font][/color]but that would be way beyond my DIY skills:[/size] [/quote] Funnily enough, I spoke with Carvin about this very amp about a year ago, in particular could they use their wonderful BX series pre-amp with the lightweight valve power stage from this. The problem with using that particualr head in terms of bass is that to do the lower frequencies justice, the transformer needs to be much bigger (and heavier) - I'm no techie so this is the best explanation I can give. Basically it'll break up like a dried out cake long before it gives you any weight - so if you want that big valvey bounce you need a big (powerful) transformer. If you want a dirty trebly/middy sound it would probably cope. Nevertheless they said that they were looking into it, but I haven't heard any more - potentially this would be somehting along similar lines to the Mesa Prodigy I guess. But I think a truly lightweight solution would be as suggested, tiny 5w power stage being fed into a much larger class D power amp. Not sure it'll have the weight of sound though, just the compressy valve break-up. Quote Link to comment Share on other sites More sharing options...
UglyDog Posted February 20, 2015 Share Posted February 20, 2015 (edited) [wildlyofftopicforasecond] [quote name='JapanAxe' timestamp='1423953308' post='2690934'] However I can confirm that all my CDs are in alphabetical order by artist. There are exceptions though, e.g. Tin Machine is filed under David Bowie. [/quote] Is that 'David Bowie' or 'Bowie, David'..? Mine are alphabetical by surname or main band name, e.g. Weller, Paul or Jam, The. I do not get out much. [/wildlyofftopicforasecond] Edited February 20, 2015 by UglyDog Quote Link to comment Share on other sites More sharing options...
Musky Posted February 20, 2015 Share Posted February 20, 2015 Just thinking out loud here, but if a mains transformer can be replaced with a SMPS is there any reason the OT of a valve amp can't be replaced with some similarly new fangled electronic wizardry? Quote Link to comment Share on other sites More sharing options...
Subthumper Posted February 20, 2015 Share Posted February 20, 2015 (edited) No or not that I know of. It takes a lot of energy to reproduce bass frequencies and too small a transformer will result in saturation, which is where the iron core has absorbed as much electromagnetic energy as it can and then starts to distort and lose frequency response. Sometimes this is good thing on guitar amps as is forms part that amps distinct tone. In the early days guitar amps deliberately had small output transformers to limit the low end to preserve the frail speakers. I recently worked on a a couple of peavey 5150/6505 60 watt combos. One was an American one the other was a Chinese one. The output transformer of the Chinese one is about half the size and difference in sound is huge. The U.S. one sounds big and articulate and the Chinese one is rather thin and strangled sounding. Hence this is why all the best sounding valve bass have huge heavy transformers. There is some news on lightweight valves though. Korg have just announced their NUTUBE which is a miniature pre amp valve. Check it out. Edited February 20, 2015 by Subthumper Quote Link to comment Share on other sites More sharing options...
JapanAxe Posted February 20, 2015 Share Posted February 20, 2015 [quote name='UglyDog' timestamp='1424436428' post='2696270'] [wildlyofftopicforasecond] Is that 'David Bowie' or 'Bowie, David'..? Mine are alphabetical by surname or main band name, e.g. Weller, Paul or Jam, The. I do not get out much. [/wildlyofftopicforasecond] [/quote] [b]Bowie[/b] comes under B, after [b]Boomtown Rats[/b] but before [b]Garth Brooks[/b]. I would have thought that was obvious (except to iTunes). Quote Link to comment Share on other sites More sharing options...
tauzero Posted February 22, 2015 Share Posted February 22, 2015 [quote name='JapanAxe' timestamp='1423906838' post='2690185'] This will be the same Stewart Ward that builds and sells transistor-powered Session Amps? He's done pretty well with them, but clearly he does have a vested interest! BTW I am not knocking Session Amps - I used to own one of the guitar combos, and it was very good for a solid state amp. [/quote] After that mention of him, I went googling and found this [url="http://www.award-session.com/pdfs/GEAR_TALK_1.pdf"]http://www.award-session.com/pdfs/GEAR_TALK_1.pdf[/url] which is very interesting and only has a few Session commercials in it. Quote Link to comment Share on other sites More sharing options...
deepbass5 Posted February 22, 2015 Share Posted February 22, 2015 Just one comment on Subthumpers comment. I did read once that the old style transformers ( big square ones) with a core made up of thin steel laminates E's T's and I's etc. If i have lost you regarding E-T- I then you need to take one apart to know what i mean, These apparently are better at supplying the oomph that the circuit needs ( slew rate etc ) than the more efficient modern toroidal transformers. Modern toroidal transformers are designed to reduce eddy current losses. So I guess are better when in an application where a consistent step down voltage is required delivering a steady current. What this article was saying that an instrument amp needs a transformer sitting there that can meet those huge surges of power on demand which is more critical for bass amps than guitar. It may be bunkum but possible that all those eddy current losses orbiting your bass amp transformer, pulling in spanners and lose screws and washers may actually act like a mob of loitering bovver boys that follow the current flow into your amp and are on hand to give your valves a kicking. I blame Back emf ? well it has something to do with it. Will some electrical engineer please step in and tell me this is rubbish. Quote Link to comment Share on other sites More sharing options...
HazBeen Posted February 27, 2015 Share Posted February 27, 2015 This NUTUBE stuff is intriguing. http://www.korg.com/us/news/2015/012212/ Wonder how long A it will take to make an amp with it, B how long it will take before bass amps are available to test. This would solve all issues (weight) with fulltube amps, IF they indeed sound like tube amps. [quote name='Subthumper' timestamp='1424472662' post='2696832'] No or not that I know of. It takes a lot of energy to reproduce bass frequencies and too small a transformer will result in saturation, which is where the iron core has absorbed as much electromagnetic energy as it can and then starts to distort and lose frequency response. Sometimes this is good thing on guitar amps as is forms part that amps distinct tone. In the early days guitar amps deliberately had small output transformers to limit the low end to preserve the frail speakers. I recently worked on a a couple of peavey 5150/6505 60 watt combos. One was an American one the other was a Chinese one. The output transformer of the Chinese one is about half the size and difference in sound is huge. The U.S. one sounds big and articulate and the Chinese one is rather thin and strangled sounding. Hence this is why all the best sounding valve bass have huge heavy transformers. There is some news on lightweight valves though. Korg have just announced their NUTUBE which is a miniature pre amp valve. Check it out. [/quote] Quote Link to comment Share on other sites More sharing options...
Ancient Mariner Posted February 27, 2015 Share Posted February 27, 2015 I don't have time to read through all the posts, but can make a few comments: Much of the tone from a valve power amp comes from interaction between the speakers (impedance load) and the amp, so running DI will not produce the same behaviour as running through speakers. The heat produced is power dissipation, and the heat from the valve heaters is just a small component of that. Those who have seen valve grids glow will know what I mean! Transformer design will affect tone - TANSTAAFL. You want tiny transformers, then that will change the tone and particularly, the desirable behaviour of the amp. Session solid state amps - I tried a couple for guitar use, albeit a long time ago, and was very very underwhelmed. Some SS amps are reputed to be good, and I own a Tech 21 Trademark 60 which was a serious amp (sounds like a very well made Marshall MG30) but they simply don't behave the same as a half decent valve amp. I have only been able to get good tones from a SS amp using compression and heavy EQ externally. Quote Link to comment Share on other sites More sharing options...
bigjohn Posted February 28, 2015 Share Posted February 28, 2015 (edited) [quote name='HazBeen' timestamp='1425025316' post='2702966'] This NUTUBE stuff is intriguing. [url="http://www.korg.com/us/news/2015/012212/"]http://www.korg.com/...ws/2015/012212/[/url] Wonder how long A it will take to make an amp with it, B how long it will take before bass amps are available to test. This would solve all issues (weight) with fulltube amps, IF they indeed sound like tube amps. [/quote] Surely they're just replacements for pre-amp valves, not power-amp valves? My current rig is the closest I've got to sounding like a valve power stage without one. It's not the same, but it's quite convincing sometimes. It takes me two valve pre-amps and a poweramp that doesn't clip easily and deals well with a hot signal, then eqing / attenuating gain so you can give the poweramp just the right sort of saturation and overdrive and let it power it up. I can get quite good Bassman, B15 and SVT sounds from it. Not bad considering it weighs about 15kg. I use an Alembic FX-1 with an Ampeg SVP-Pro through the effects loop. Edited February 28, 2015 by bigjohn Quote Link to comment Share on other sites More sharing options...
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