davehux Posted August 31, 2012 Share Posted August 31, 2012 Just got an UK made LB30 from Mike_M, and a lovely thing it is too. Following advice on here I bought a couple of Mullard ECC81's to replace the 83's in the preamp and stop it grinding up too soon. Opening up the unit, I see that there are 3 x 83's in there, where I was expecting 2 x 83 and 1 x 82. Looking underneath at the circuit board, it has ECC83 printed at all 3 locations. Can someone enlighten me as to which of the 83's I should swap for the 81's and should I get an 82 to replace the other 83? I like a bit of dirt, but it will be a gigging amp for small pubs, so I don't want it to run out of clean too soon. Cheers Quote Link to comment Share on other sites More sharing options...
voxpop Posted August 31, 2012 Share Posted August 31, 2012 If I remember rightly you need to replace the valves on the left. Quote Link to comment Share on other sites More sharing options...
franzbassist Posted August 31, 2012 Share Posted August 31, 2012 HI there Marc is correct, the two preamp valves are the ones to the left as you look at the amp from the front. I fitted two NOS Mullard ECC81s, giving [size=4]about 60% of the standard ECC83's gain, that cleaned up the sound up perfectly for me.[/size] [size=4]Ashdown recommend an ECC82 as the driver.[/size] [size=4]I have a number of NOS valves that I bought for my LB30 if you fancy buying them off me [/size] [size=4]Cheers[/size] [size=4]Gareth[/size] Quote Link to comment Share on other sites More sharing options...
davehux Posted August 31, 2012 Author Share Posted August 31, 2012 Hi Gareth It was your video and the valve listing on your LB30 sale posting that got me on the path of swapping out the 83's for 81's - thanks I've got a pair of 81's now, but if you have an 82, I'd be very interested in buying it ATB Dave Quote Link to comment Share on other sites More sharing options...
franzbassist Posted August 31, 2012 Share Posted August 31, 2012 Hi Dave I'm glad my video was a help! I have two Mullard 82s from the 80s that you could have, also a nice Brimar and a JAN-GE from the US. Also have two sets of EL84s if you fancy beefing up the power section - a set of vintage Sovteks and a set of vintage Philips. Drop me a PM if you would like any? Cheers Gareth Quote Link to comment Share on other sites More sharing options...
davehux Posted August 31, 2012 Author Share Posted August 31, 2012 PM sent Quote Link to comment Share on other sites More sharing options...
davehux Posted September 5, 2012 Author Share Posted September 5, 2012 And so we now have the results of the Little Bastard Valve Swapout Test 2012 The volume control starts in the 7 o'clock position for no volume. All settings are based on that datum. No1 - ECC83 x 3 - breakup at 9.00 - total distortion at 12.00 No 2 - 2 x ECC81 in preamp. ECC83 as driver - breakup at 12.00 - total distortion at 2.00 No 3 - 2 x ECC81 in preamp. ECC82 as driver - breakup at 2.00 - total distortion at 3.30 Whoever worried that this little pocket rocket couldn't hold it's own in an average pub/club band, really should hear one in action. They are 'king loud, and playing with the valves gives so much more scope to find your own level of graunchiness than an SS amp Quote Link to comment Share on other sites More sharing options...
umph Posted September 6, 2012 Share Posted September 6, 2012 i'd recomend the 81 as the driver valve rather than the 82 as the splitter will have been designed for the 81 Quote Link to comment Share on other sites More sharing options...
davehux Posted September 13, 2012 Author Share Posted September 13, 2012 Finally got to give the little chap a proper workout with the full band at our practice last night, using my Ashdown MAG410 cab. It was up against a guitard who only knows one volume (LOUD!!!), keys, big drums and vox. No problem whatsoever in being heard. Lead plugged into the active socket to drop the gain, volume at 11 o'clock. Lovely valve lushness with almost no overdrive on it at all. Floor rumbling bass, plenty of top to cut through the mix. These really are the dogs donuts. Gigging it tomorrow in a small pub, which will be the same sort of volume as last night - can't wait!!!!! Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 16, 2012 Share Posted October 16, 2012 I have the same amp and it's really lovely. The two preamp inputs offer a pretty wide choice... but I have one bass that is just slightly too loud for the "low" input and too quiet for the "high" one. So I was considering a tube swap to have slightly less gain in the preamp section. From what I read I guess I should only replace the two tubes on the left side, right? Still haven't dismounted the amp so don't know what tubes I'm gonna find in it. Quote Link to comment Share on other sites More sharing options...
dan670844 Posted October 16, 2012 Share Posted October 16, 2012 The phase inverter the third preamp valve to the right should be an ECC82 and should be balanced i.e. both halfs matched, if it not the power valves wont like it! I have found that the best combo to be as is, as adding lower gain ecc83 like mullards, tends to knock off the top end and reduce the efficacy of the tone stack as it it needs quite a bit of juice to drive and and yes they are flipping loud for what they are. Esp with the LB/VS cabs as they are very sensitive. The trick with these is to play around with your vol and tones on your bass! and make up the treble bleed you loose with turning up the treble on the amp. Although I have never used an active bass on mine. Dont bother swapping out the jj power valves they are defo the most powerful EL84's, other brands i tried the output defo dropped. The best bit is the output transformer derived di. Its the rollocks, you will impress everyone with your tone! Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 16, 2012 Share Posted October 16, 2012 All my basses are passive but for example a 4 strings with AlNiCo5 magnets humbucker is OK with the "low" input as it's got a lower output while the 5er (Ceramic humbucker) must be used in the High input or it will sound fuzzy. So I guess I only have to replace only the first tube on the left side (closer to the input)? I'll leave the power section as is for now... would be nice to swap the EL84s with Genelex but as long as they work I won't touch them. Quote Link to comment Share on other sites More sharing options...
dan670844 Posted October 17, 2012 Share Posted October 17, 2012 you could change v1 the 1st preamp tube on the left to a lower gain ecc83/ 57xx etc it will lower the gain through the preamp but I found it tends to darken your sound, it wont sound muddy as the lb has the girth to carry it off. if that your thing try it, it rather like turning both volumes down on a jazz, you get an aston family mann type tone. i would check that you have got a balanced '82 in V3. I have tried loads of el84 in mine real mullards, sovteks, mullard reissue, genelex reissues, even russian mil nos. the jj's work the best with these amps, they perform the same as the russian mil nos, but are cheaper, they have far more power and clean punch than any others. thats not to say that the others arent good, the mullard reissues are nice they give a midrangy growl perfect for rock. But thats the whole point of this amp, changing the tubes changes the tone and character, have fun, i have a shoe box of full of tubes for this amp! its a real journey Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 17, 2012 Share Posted October 17, 2012 Ok, I removed the hood from the little sucker... and found a few strange things. The two preamp tubes at the left side are two 12AX7 while the last one (right side) is a 12AU7. The power tubes are Ruby tubes, just like all the preamp tubes. And I'm sure they're original, the amp has never been dismounted before... I can see it. Quote Link to comment Share on other sites More sharing options...
franzbassist Posted October 17, 2012 Share Posted October 17, 2012 [quote name='Matte_black' timestamp='1350480748' post='1839449'] Ok, I removed the hood from the little sucker... and found a few strange things. The two preamp tubes at the left side are two 12AX7 while the last one (right side) is a 12AU7. [/quote] 12AX7 is the US code for the European code ECC83, likewiswe 12AU7 is an ECC82. Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 17, 2012 Share Posted October 17, 2012 Yes but I thought there was an ECC83 on the left and two ECC82 on right. Quote Link to comment Share on other sites More sharing options...
franzbassist Posted October 17, 2012 Share Posted October 17, 2012 The "official" setup is two ECC83 for the preamp (the two valves next to each other), with a single ECC82 as the driver. Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 17, 2012 Share Posted October 17, 2012 I've found that switching the bass shift on I can almost tame the distorsion. Now I can use the amp without breakup 'til 3:00. But the last part of the pot is always grindy. The unit has Ruby tubes everywhere... strange, I thought I was going to find JJs. Anyway, I've put an old 12AU7 in the place of the Ruby and looks like the distorsion went down a little bit. Or it's a placebo effect. Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 17, 2012 Share Posted October 17, 2012 [quote name='dan670844' timestamp='1350460786' post='1839045'] you could change v1 the 1st preamp tube on the left to a lower gain ecc83/ 57xx etc it will lower the gain through the preamp but I found it tends to darken your sound, it wont sound muddy as the lb has the girth to carry it off. if that your thing try it, it rather like turning both volumes down on a jazz, you get an aston family mann type tone. i would check that you have got a balanced '82 in V3. I have tried loads of el84 in mine real mullards, sovteks, mullard reissue, genelex reissues, even russian mil nos. the jj's work the best with these amps, they perform the same as the russian mil nos, but are cheaper, they have far more power and clean punch than any others. thats not to say that the others arent good, the mullard reissues are nice they give a midrangy growl perfect for rock. But thats the whole point of this amp, changing the tubes changes the tone and character, have fun, i have a shoe box of full of tubes for this amp! its a real journey [/quote] Should I replace ONE of the twin 12AX7s? I always thought I needed to swap the one closer to the output but since I've found 2 AX and 1 AU I thought the twins should have been left "matched". Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted October 17, 2012 Share Posted October 17, 2012 Matching doesn't apply to preamp valves, unless you are selling valves at a premium to audiophiles. Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 17, 2012 Share Posted October 17, 2012 "Matching" isn't what I was thinking of but at least having two of the same type Quote Link to comment Share on other sites More sharing options...
dan670844 Posted October 19, 2012 Share Posted October 19, 2012 The 12ua7/ Ecc82 is the phase inverter and it must be balanced ie the left and the right halfs, you should not use any old Ecc82 Are you sure you have a uk one, the chinese ones have rubys and the uks jj's the rubys are good valves Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 19, 2012 Share Posted October 19, 2012 Mine is made in PRC, in fact Quote Link to comment Share on other sites More sharing options...
dan670844 Posted October 19, 2012 Share Posted October 19, 2012 [quote name='Matte_black' timestamp='1350636934' post='1841452'] Mine is made in PRC, in fact [/quote] Nothing wrong with that I have a UK one and a chinese one and I cant tell the difference really if the same valves are used! Quote Link to comment Share on other sites More sharing options...
Matte_black Posted October 19, 2012 Share Posted October 19, 2012 I think it's a great product but the case is awful. The tolex is cheap, the glue of the tolex is weak etc. - I think I'm gonna make a real wood case for the little beast. It's worth it! Anyway, with my personal bass the head is clean 'til 3:00... from 3 to 5 (last 1/4 of the rotation) it's distorsionland but I guess it's due to the power stage, not the preamp. Shame it's 30w, if it was 50w it would have been giggable with a wider selection of cabs. With 30w you have to use a 4x10" or 2x12" to be on the safe side. Quote Link to comment Share on other sites More sharing options...
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