Pbassred Posted April 4, 2015 Share Posted April 4, 2015 I confess that I thought a search might turn up several threads, but perhaps I used the wrong terms ... I like my Littlemark tube amp although the tube is completely inaudible. Reading around what "tube sound" is it find that most of it is in the power section so a tube pre isn't going to warm it up as much as singe it. Since the intention of my amp is to use it in various volume settings (including as a DI once) a pure valve amp wouldn't suit. However I also read that much of the classic valve sound actually comes from transformer saturation. So it surprises me that no one markets a "Transformer Saturation" pedal, and no one discusses making one. Quote Link to comment Share on other sites More sharing options...
dannybuoy Posted April 4, 2015 Share Posted April 4, 2015 You should go on Dragon's Den! Quote Link to comment Share on other sites More sharing options...
Muzz Posted April 4, 2015 Share Posted April 4, 2015 I thought the LM Tube was the most pointless of the tubed mini heads - you'd hear much more valve with something like a Streamliner or even a GK Fusion. The 'big transformers' thing appears to produce this mystical thing called 'heft', which is much toted on here - some folk swear by it. some folk don't....YMMV, etc... Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted April 4, 2015 Share Posted April 4, 2015 I suppose it's a bit like understanding why the sensations of a V12 TVR cannot be replicated with a Renault 5, even with a turbo. There are some excellent emulators out there, but beef is beef, I find. Quote Link to comment Share on other sites More sharing options...
Roland Rock Posted April 4, 2015 Share Posted April 4, 2015 [quote name='Dad3353' timestamp='1428182589' post='2738971'] but beef is beef, I find. [/quote] try telling that to Findus and Tesco Quote Link to comment Share on other sites More sharing options...
Dad3353 Posted April 4, 2015 Share Posted April 4, 2015 (edited) [quote name='Roland Rock' timestamp='1428182952' post='2738975'] try telling that to Findus and Tesco [/quote] Edited April 4, 2015 by Dad3353 Quote Link to comment Share on other sites More sharing options...
Pbassred Posted April 4, 2015 Author Share Posted April 4, 2015 Sorry..... how did this turn into a LMT800 slag fest? The TVR analogy is good though. More expensive to run, less reliable, the requirement to warm up/warm down the engine. Not something that you want to take to the office everyday. However you can upgrade the shocks and brakes on a Renault to get something fast and reliable that you don't have to treat like silk. My Markbass LMT800 and barefaced cab has grunt that I haven't found a use for yet. I had to make a special attenuatior to tame it. Meanwhile Back to THIS thread which is applicable to ANY amp. Quote Link to comment Share on other sites More sharing options...
King Tut Posted April 5, 2015 Share Posted April 5, 2015 Would this be why none of the class D stuff I've tried ever seems to have that indefineable goodness I can get from my old Trace AH250£ Quote Link to comment Share on other sites More sharing options...
karlthebassist Posted April 5, 2015 Share Posted April 5, 2015 To say that the sound of a valve amp is in the transformer isnt really the case. My experience/understanding of this comes from hifi equipment, but it's the same principle. In fact, my current hifi amp uses EL34 output tubes (in Ultralinear mode) which are found in many guitar amps. A good output transformer sounds transparent. It should have no effect on the tonality, speed, or character of the sound. The reason that the tone of an amp sounds to be "improved" when the output transformers are replaced with better quality units is that better one is simply more transparent so more of the characteristics that make up that 'tube sound' get through. Interestingly with tube rolling, unless the output valves you are replacing are of low quality or worn out, it's changing the input stage valves that has the biggest effect of changing the character of the amp. Quote Link to comment Share on other sites More sharing options...
Beer of the Bass Posted April 5, 2015 Share Posted April 5, 2015 [quote name='King Tut' timestamp='1428224161' post='2739184'] Would this be why none of the class D stuff I've tried ever seems to have that indefineable goodness I can get from my old Trace AH250£ [/quote] Not really, this is referring to the effect of passing audio through transformers like the output transformer of a valve amp. Transformer-coupled stages are often touted as a feature on studio gear too. The Trace uses a transformer based power supply, but does not have any in the signal path AFAIK. Quote Link to comment Share on other sites More sharing options...
discreet Posted April 5, 2015 Share Posted April 5, 2015 (edited) A 'heft' pedal..? I'd buy that. The Tech-21 VT Bass series is the closest I've used, but there's definitely a niche in that market. Edited April 5, 2015 by discreet Quote Link to comment Share on other sites More sharing options...
Lozz196 Posted April 6, 2015 Share Posted April 6, 2015 Yep, a pedal that just adds valve-heft to the signal, no eq, no level, no gain, just valve-heft to add to the amp that you already like. If only............... Quote Link to comment Share on other sites More sharing options...
tauzero Posted April 6, 2015 Share Posted April 6, 2015 Have you tried reading [url="http://www.award-session.com/pdfs/GEAR_TALK_1.pdf"]http://www.award-session.com/pdfs/GEAR_TALK_1.pdf[/url] ? Quote Link to comment Share on other sites More sharing options...
Muzz Posted April 6, 2015 Share Posted April 6, 2015 Slag fest? Hahahahaaaa... You said yourself "[color=#282828][font=helvetica, arial, sans-serif] [/font][/color][color=#282828][font=helvetica, arial, sans-serif]although the tube is completely inaudible", I was agreeing with you. [/font][/color] Quote Link to comment Share on other sites More sharing options...
discreet Posted April 6, 2015 Share Posted April 6, 2015 (edited) Hybrid amps with a single 12AX7 in the pre circuit are largely ineffective, in my opinion. You do get some warmth, but I think it's mainly there so the manufacturer can say it's a 'valve amp'. There should be a label on the front stating 'valve is for marketing purposes only'. I had a VT Bass for a while and that does a fair valve grit impersonation, but has no valve in it... you still don't get much heft, though. I believe the reason for the perception of 'heft' in valve power amp transformers is due to 'sag'. As I understand it, 'sag' refers to the reduction of the power supply voltage in response to large transient signals which lends an important dynamic 'feel' to the amp that is not found in solid state amps... I could be wrong of course, as I'm no techie. But I do know the most 'heft' I've ever experienced in 40 years of playing bass has been from all-valve amps. Edited April 6, 2015 by discreet Quote Link to comment Share on other sites More sharing options...
obbm Posted April 6, 2015 Share Posted April 6, 2015 [quote name='discreet' timestamp='1428355816' post='2740593'] I believe the reason for the perception of 'heft' in valve power amp transformers is due to 'sag'. As I understand it, 'sag' refers to the reduction of the power supply voltage in response to large transient signals which lends an important dynamic 'feel' to the amp that is not found in solid state amps... I could be wrong of course, as I'm no techie. But I do know the most 'heft' I've ever experienced in 40 years of playing bass has been from all-valve amps. [/quote] Early all-valve guitar amps used valve rectifiers, such as EZ80, EZ81 and GZ34. These were very good at 'heft'. This has got me thinking that one way forward might be a simple 3-watt amp with valve rectifier driving a DI transformer. Quote Link to comment Share on other sites More sharing options...
discreet Posted April 6, 2015 Share Posted April 6, 2015 [quote name='obbm' timestamp='1428357018' post='2740604'] Early all-valve guitar amps used valve rectifiers, such as EZ80, EZ81 and GZ34. These were very good at 'heft'. This has got me thinking that one way forward might be a simple 3-watt amp with valve rectifier driving a DI transformer. [/quote] Dave, do it! If you can come up with a 'valve heft' pedal it'll be worth a fortune! Quote Link to comment Share on other sites More sharing options...
tauzero Posted April 6, 2015 Share Posted April 6, 2015 [quote name='discreet' timestamp='1428355816' post='2740593'] I believe the reason for the perception of 'heft' in valve power amp transformers is due to 'sag'. As I understand it, 'sag' refers to the reduction of the power supply voltage in response to large transient signals which lends an important dynamic 'feel' to the amp that is not found in solid state amps... I could be wrong of course, as I'm no techie. But I do know the most 'heft' I've ever experienced in 40 years of playing bass has been from all-valve amps. [/quote] That's one of the things mentioned in the Stewart Ward article I linked to above. Basically, the power supplies were crap and that made the amp sound good. Next up, a variable-voltage SMPS which emulates valve-rectified power supplies... Quote Link to comment Share on other sites More sharing options...
discreet Posted April 6, 2015 Share Posted April 6, 2015 [quote name='tauzero' timestamp='1428357699' post='2740612'] That's one of the things mentioned in the Stewart Ward article I linked to above. Basically, the power supplies were crap and that made the amp sound good. [/quote] Ah, naturally I didn't read that. But I hope this means a heft pedal is possible. Quote Link to comment Share on other sites More sharing options...
cheddatom Posted April 7, 2015 Share Posted April 7, 2015 [quote name='discreet' timestamp='1428355816' post='2740593'] ...As I understand it, 'sag' refers to the reduction of the power supply voltage in response to large transient signals which lends an important dynamic 'feel' to the amp that is not found in solid state amps... [/quote] What is the actual effect? What happens when you give the hefty amp a large transient signal (I guess you mean lots of fast attack?). Surely this can be replicated with a compressor? Quote Link to comment Share on other sites More sharing options...
discreet Posted April 7, 2015 Share Posted April 7, 2015 (edited) [quote name='cheddatom' timestamp='1428399387' post='2740830'] What is the actual effect? What happens when you give the hefty amp a large transient signal (I guess you mean lots of fast attack?). Surely this can be replicated with a compressor? [/quote] I've used many different compressors over the years and they don't provide 'heft'. I'm not tech in any way, but I suspect it's something to do with power supply voltages? Edited April 7, 2015 by discreet Quote Link to comment Share on other sites More sharing options...
cheddatom Posted April 7, 2015 Share Posted April 7, 2015 If the voltage sags when an extra loud transient is played, then I guess that would make this part relatively quieter, which would be easy to replicate with a compressor Maybe there's some research on this but i'm struggling to find it. What I'm after is some sort of quantifiable evidence of the effect a big valve amp has on the input signal. From everything I'd read previously, I'd assumed it was a fairly subtle and fast compression Quote Link to comment Share on other sites More sharing options...
tauzero Posted April 7, 2015 Share Posted April 7, 2015 To quote from the article that I've linked to above, and mentioned the link to above, so no-one has to go to the trouble of clicking on the link above: [i][b]Do valve amplifiers really produce a compressed ‘spongy’ sound?[/b] Yes they can do, but not all valve amplifiers do. So it is incorrect to assume that because an amp has valves in it, that it will automatically exhibit this characteristic. The reason some amps compress is due to the power supply and the rectifiers which convert the incoming AC mains (line) voltages into the DC which the electronics in the amp needs to function. Some valve amplifiers have valve rectifiers, but most have solid state rectifier diodes. The valve amps that incorporate the latter DO NOT compress the signal. So that rules out about 95% of the popular valve amps on the market. If you particularly like the effect that this kind of compression brings, then you should ask your amp dealer if the amp you are trying has valve rectification. Amps that compress in this way seem to be very loud when you initially play a clean loud sustained chord and then it soon sinks down into a mushy semi-distorted tone. Under these conditions, the rectifier valve is unable to deliver sufficient current (known as current limiting) to the power amp, so the voltage across the output valves severely drops to a level where the power is reduced and distortion creeps into the tone. When you stop playing, the power supply returns to its former levels, until you play another loud chord and the same effect repeats. The power supply needs just a fraction of a second to ‘re-charge’, so you don’t really notice anything happening. Usually, it’s only low powered amps that have valve rectification. Larger 50-100 watt amps have solid state diodes. This has been the case since about 1963, when higher powered amps first started to come onto the market and valve rectifiers were unable to be economically used, in what were then, just cheap guitar amps. Everything was down to the cost. But really it was an improvement, because everyone wanted loud un-distorted power back then. Remember, these amps were designed long before distortion was a desirable guitar sound. Classic amps like the Fender Twin Reverb, known for it’s loud ‘n’ clean performance, owe their reputations largely to the fact that they have solid state rectification and two very efficient speakers with large magnets. The classic Marshall 50 and 100 watt ‘Super Lead’ amps also are equipped with solid state rectification. It was really only the low powered amps up to the 30 watt ‘Bluesbreaker’ types that had valve rectifiers. VOX AC30s employ (and still do) valve rectifiers, as did the Selmer ‘Treble ‘n’ Bass 50’, Zodiac 30 Twin and Thunderbird 50 combo amps - using the famous GZ34 on an octal base, but 50 watts is right on the limits of its current capabilities at 250mA. Some say that this is exclusive to valve amps, but again, that’s not strictly true. Tranny amps behave pretty much in the same way as a valve amp with solid state diodes. However, it is possible to build a solid state power supply for an amp which has intentional, and even adjustable, current limiting. So it would be quite possible to surpass the effects caused by a valve rectifier! Just how useful this would be is another question... but it is easily possible. It’s worth saying though, that I have never seen a tranny amp made this way. That’s probably due to the fact that it would make it much more expensive and... tranny amps are expected to be cheap. If player’s prejudices were reversed at some time... then I’m sure a brilliant tranny amp could be designed that would be a top selling product! A classic in time even?[/i] Quote Link to comment Share on other sites More sharing options...
51m0n Posted April 7, 2015 Share Posted April 7, 2015 The problem with this 'heft' is that no one really knows what the hell anyones talking about. I've never rally experienced anything in a valve amp that I thought was better than a really great solid state amp. Equally warmth means something different to pretty much everyone too. Define heft properly, in a measurable way, and it can be reproduced (and almost certainly recreated with different tools, i.e compression or modelling) until then its just astrology for bassists Has anyone tried a Kemper modelling with bass? Its purported to be the absolute pinnacle of modelling amps, used by an awful lot of top studios rather than mic up a bunch of hoary old guitar amps that require mega bucks in maintenance and who knows what. Supposedly 'feels' right according to pretty much everyone who has used one. I'd be really interested to know if the tube officianados here find that it suffices for them.... Quote Link to comment Share on other sites More sharing options...
discreet Posted April 7, 2015 Share Posted April 7, 2015 Well that's the problem. It's very hard to describe 'heft'. I only experience it with valve amps. I also call it the 'all-valve bounce'. Quote Link to comment Share on other sites More sharing options...
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