essexbasscat Posted June 24, 2012 Author Share Posted June 24, 2012 [quote name='stingrayPete1977' timestamp='1340544526' post='1705855'] Oh and BTW you might not even need a valve, trust me I have done this on my old evo many times even though I looked after it, It always improved things [/quote] Is there a valve you'd recommend ? Quote Link to comment Share on other sites More sharing options...
RandomBass Posted June 24, 2012 Share Posted June 24, 2012 (edited) As for balancing the output across the strings using the VU meter, the percieved loudness across the frequency spectrum requires much less energy (and hence output voltage) as you move up the frequency range. Lower frequencies like our beloved bass ones require much more energy to be heard at the same level. This means more voltage, and the VU meter needle responds to the varying voltage. So the low frequencies will always cause more needle swing than higher ones. If you had the same amount of needle swing across all 4 strings, the D and G would actually sound much louder than the E and A, which would be very unbalanced. Alex 'Barefaced' Claber* covered this in one of his excellent BGM columns a while back, showing the amount of power required to reproduce various frequencies at a specific loudness - the variation is huge, and explains why we need lots of watts to compete with guitarists and their low output amps. Im convinced we are moving forward with your original 'quiet' issue. Cheers Geoff * Alex, if you are following this - apologies, but I just couldn't resist Edited June 24, 2012 by RandomBass Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted June 24, 2012 Share Posted June 24, 2012 [quote name='essexbasscat' timestamp='1340548068' post='1705949'] Is there a valve you'd recommend ? [/quote] Im trying to think what make it was but it sounded much smoother after, it was one of the gold plated pin ones....I will have a look as the old box was about somewhere but its been 3 or 4 years since I went all Genz. Quote Link to comment Share on other sites More sharing options...
stingrayPete1977 Posted June 24, 2012 Share Posted June 24, 2012 Here you go pretty sure it was one of these [url="http://tubedepot.com/jj-ecc83g.html"]http://tubedepot.com/jj-ecc83g.html[/url] Failing that I think this is the standard one, you can get these with the gold pins too I think. [url="http://thetubestore.com/ehx12ax7.html"]http://thetubestore.com/ehx12ax7.html[/url] Quote Link to comment Share on other sites More sharing options...
essexbasscat Posted June 24, 2012 Author Share Posted June 24, 2012 RB- thanks for the answer about the meter and voltage/ frequency related issues. I'll stick with the Db meter and ears for balancing strings ! BTBL - appreciate the sentiments, it's there to be used. I'm just a bit cautious I guess, as I've ran amps hard in the past to keep up with drummers etc, only to find that they break down sooner rather than later. These days I much prefer to have extra power on tap above the demands of the situation, more flexibilty and greater reliability etc. Pete - thanks for taking the time to dig up those links, I'll report back. gjones- thanks for the EQ tip. Quote Link to comment Share on other sites More sharing options...
RandomBass Posted June 24, 2012 Share Posted June 24, 2012 Use the VU meter just like you would an amp with a single peak LED. Once the needle gets into the red zone, that's when a traditional peak LED will be lighting up. Peaking now and again is fine. And the beauty of the ABM is that even when it does head into the red heavily, the overload is handled very nicely and doesn't go into horrible transistory distortion - especially if you are using the valve side of the input stage. Its a nice place to be. I've seen several comments on here and TB about insufficient volume from Ashdown amps (MAG and ABM). Invariably the answer is getting that input meter needle moving to give the strongest signal feeding the power amp stage. In my experience these amps are quite heavily over engineered and will take a lot of abuse, so never worry about driving them hard or properly. Cheers Geoff Quote Link to comment Share on other sites More sharing options...
essexbasscat Posted June 24, 2012 Author Share Posted June 24, 2012 OK, firstly, a huge THANK YOU to everyone here that's been kind enough to join me on the good ship Desperate Weighing the whole thing up, I guess I was pushing the head quite hard last night and it barely kept up. Today's discussions have made me realise I'm not really comfortable with doing that TBH, the amp must be quite well engineered to have put up with what it did already. The way forward at the moment seems to be a service of the pots, sliders and valve and see where that goes for now. It also wouldn't do any harm to beef up the pickups on my passive basses. It also wouldn't hurt to have a peek at the cab market and see what's around at 4ohms that isn't the size of a large dog kennel and is light enough to leave my shoulders joints intact. I I'll report back once there's progress. Again, thank you to everyone that's been here today, it's really appreciated. Hopefully I'll get the chance to thank a few of you personally at a bass bash Quote Link to comment Share on other sites More sharing options...
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