Oxblood

[quote name='lukeward2004' post='5006' date='May 23 2007, 11:24 AM']I have to say, ive never liked Marshall bass amps - Ive tried a few in the past and they have always seemed to lack definition, hardly any Midrange and sounded very honky through my cab. Ive not tried some of the newer stuff, but the older ones I have tried have left me cold in the past. Im open minded though so ill happily try some newer ones if the chance comes up![/quote] I think a lot of it stems from the fact that Marshall have never properly addressed themselves to our end of the market. They just don't seem to take it seriously, compared with all the effort they put into their core guitar market. Not enough thought, not enough R+D effort, not enough interest in what bass players want. It's a real shame.

[quote name='1976fenderhead' post='4467' date='May 22 2007, 04:48 PM']That sounds interesting... so how would I go about wiring it in the cable? What would I solder the capacitor ends to?[/quote] You place it in the positive ('hot') signal line of the guitar cable. Easiest way to do this (assuming the capacitor is physically small enough) is to solder one end of the cap to the tip of the jack plug and the other end of the cap to the signal line of the cable. Doesn't matter which end of the cable you fit it into, or which way round you solder the cap.

[quote name='owen' post='4339' date='May 22 2007, 01:57 PM']Thanks y'all I knew that there was a repair diary floating around, I just could not find it. It looks like Oxblood's VA 350 but with a GP12 pre as well. He is thinking of flogging it but I think I will try and persuade him to get it serviced and use a decent speaker (he has an EV 18" in a W horn thing) and then see how he feels about it. Of course there is the downside that it is stupid heavy.[/quote] Whereabouts are you, owen? I'm in East London. If it were possible, I'd be very interested in having a look inside the beastie, if only to educate myself properly as to the differences between it and the VA350.

[quote name='rodl2005' post='4217' date='May 22 2007, 11:05 AM']I've used all types of amps in my 27 yrs of playing live in pubs & most of whats above I agree with. Cuppla things IMHO valve amps do NOT need anymore servicing than S.S. amps. As long as U put quality tubes in they should last as long as said above- 10 yrs... more depending on use! BUT IMHO U should have ANY regularly used amp serviced every few yrs-depending on use! & IME I've spent equally as much on my s.s. amps as I have on my tube amps over the last 27 yrs! IME( :-) sorry 4 all the IME 's etc... ) usually when a valve amp goes down -it's a tube/s when a s.s. amp goes down..... good guess!! & 4 me has been lotsa $$$$. Also- sure [b]a poorly designed/made valve amp is gonna sound just-almost ;-) - as bad as a poor s.s. amp. Warm & fat sound only happens when the valve amp is nice, speakers are good & bass is good! IME!!!!!!!!!!!!!![/b][/quote] IME too !

[quote name='warwickhunt' post='3006' date='May 20 2007, 06:29 PM']Why do people always assume valve = big fat sound? I've owned a Boogie 220 and a 400+ and you could cut glass with the tone from both of them (regardless of which bass I put in the front end). Yet I've had SS amps that have been silky smooth and buttery![/quote] Good point. While it's broadly true to say that most valve instrument amps tend toward the warm midrangey woofy thing, it's by no means a given. The sound of a valve amp is hugely affected by circuit design factors: which valve types have been chosen for what parts of the circuit, the operating conditions they're being run under (i.e. DC voltage levels, bias point etc), the kind of EQ stage that's being used and so on.

Gosh, that's a surprise. Righty ho then. Whatever Steve's reasons may be for not wanting to do his thing on dis hya forum, I'll respect them.

I suspect that Thumper is currently unable to get to his computer, having accidentally imprisoned himself inside an enormous Bill Fitzmaurice sub-woofer. That'll teach him to use 5 minute construction adhesive!

The VA350 and VA400 are extremely similar, but I understand that there are some interesting differences, the main ones being that apparently the VA400 has an Ultralinear output stage (i.e. the screen grids are run from special taps on the OPT primary) and in order to squeeze out the extra watts, it runs the output valve anodes at a frankly scary 730 Volts. Consequently, the VA400 has a reputation for wearing out power valves very quickly, unless they're rugged enough to take it. Fortunately the Sovtek 6550WE are tough enough, and reasonably priced. Re. the PDF file: anyone working on a VA400 should be aware that the power amp circuit diagram shown in that document is actually the one for the VA350, and contains at least one inaccuracy: in the diagram, the screen resistors are shown as 22 Ohm, when in fact they should be 220 Ohm. To the best of my knowledge, no accurate diagram of the VA400 is known to be publicly available. Not even its designer, Clive button, has one!

[quote name='ped' post='2851' date='May 20 2007, 01:45 PM']There are some wonderfully knowledgeable people out there who can, as Oxblood says, open up a well made valve amp and fix it in seconds for bugger all. [b]It is a lost art.[/b] I know that if anything happens to mine it is nothing that cannot be fixed pretty easily by some people on this forum, most of whom will be only too willing to help for the sheer enjoyment of fiddling around with these really quite wonderful pieces of equipment![/quote] Not yet it ain't! As long as people want to make (and, more importantly, [i]use[/i]) valve gear, there will be wild-eyed solder-heads out in the backwoods with the necessary skills to fettle 'em. Hurrah!

As one who lost all his gear in a burglary many years ago, I'm really sorry to hear about this. You've given me an idea. I'm going to contact the mods and suggest that BC has a dedicated Stolen Gear section.

LFalex, I feel for you. You've been bitten by a bad valve product, and understandably you're very wary about throwing any more money in the direction of things hot and glowing. With any amp, whether valve or SS, obviously it's design and build quality that matters, and you'd expect a reputable - nay, legendary - name like Ampeg to be the bees knees, wouldn't you? But you've been landed with a dog, and you're not alone. Recently, when I was round at Thumper's gaff to hear his cabs, he mentioned having once owned an Ampeg valve pre (probably an SVP-Pro - can't remember exactly) and he was just as disappointed with it. "I looked inside and the build quality was dreadful" was his basic assessment. That's why in my last post I was careful to specify "a [i]well designed/built[/i] valve amp". If it were in my power, I'd go out right now and buy you a nice tasty point-to-point wired, hand-built Bass head or rackmount pre, then sit back and watch your smile get wider and wider. [quote name='Lfalex v1.1' post='2773' date='May 20 2007, 12:01 PM']Uh-oh. Counterpoint time. I've owned ONE fully tube device, an Ampeg SVP-Pro. It can work fine, and when it does, it sounds lovely. It has never made it through a whole gig, no matter how short. It just cuts out, and won't come back. It's been looked at 3 times, and no-one can fix it. YES! Of course it's out of warranty. And it always brings its buddy, captain 50hz hum to the party. It has had a second full set of valves, supposedly "good" ones, yet still it happens. Conversely, my Trace Elliot is now 10 years old, and has suffered nought but a microphonic pre-amp valve (!) and a loose connection that I found and hardwired. My "little" 80w 1x12 practice amp is now over 20 years old and just keeps on delivering excellent tone against a silent background. It's Solid State I'm afraid. I'd love a quiet, modern sounding, all-valve front-end, but I really can't be convinced to part with the money based on my experiences of poor reliability. All of my problems have been pre-amps using 12AX7s (the Ampeg uses an AU7 for its OD circuit), so I daren't ever use anything that uses valves for power amplification![/quote]

+1 to BOD2's advice. Despite popular myth, valve amps are not inherently less reliable than solid state gear. In fact, it can be argued that the opposite is the truer case. A well-designed/built valve amp that is new, or an older one that has been properly maintained, will give years of loyal, worry-free service. While of course you should treat them with care, mechanically valves are pretty rugged (hell, they got us through WWII !), and electrically they'll withstand an astonishing amount of abuse, whereas solid state devices have a lovely habit of falling over STONE DEAD in the blink of an eye as soon as they get a bit too much voltage on the power rails or receive a static shock. Also, by and large, valve amp circuits tend to be a lot simpler than their SS equivalents, and are usually made up of tried-and-trusted architecture with which any good valve technician will be familiar, even if he/she hasn't got access to a circuit diagram. Consequently, should your valve amp develop the odd fault that needs professional attention, it'll be a whole lot easier to diagnose and fix than a box stuffed with a thousand tiny, fragile devices, some of which may be: 1. difficult or impossible to identify without reference to the manufacturer's data 2. one-off chips only available through the manufacturer at a premium price ...or in the case of vintage SS gear, 3. obsolete types for which there is no drop-in modern equivalent! By now, I hope you're beginning to feel that owning a valve amp is a pretty attractive proposition. However, your biggest challenge lies in trying to obtain something worth having, given your limited budget. Sadly, these days, even half-knackered tatty old valve gear in need of a total overhaul will sell for silly prices because it's supposedly "vintage" or "rare". The days of stumbling across a lovely old Vox/Marshall/Sound City head in your local junk shop are long gone! One classic British brand with plenty of character that still occasionally goes for reasonable money is Selmer. Tone? Think Ronnie Lane/Small Faces. Nice! There's usually at least one Selmer amp on eBay at any given time. For instance: [url="http://cgi.ebay.co.uk/Selmer-Super-Zodiac-100-Valve-Head-Circa-1969_W0QQitemZ260119349277QQihZ016QQcategoryZ10171QQssPageNameZWDVWQQrdZ1QQcmdZViewItem"]Selmer Super Zodiac Twin 100[/url] 2 channels, 100 Watts, pre-set tone selector ...AND tremelo!

Hi Subthumper I think it must be me you're thinking of. I was debating the pros and cons of buying a commercial valve pre for my new VA350 rig, adapting an old piece of kit or building something completely from scratch. That looks like a really nice kit-build job to me: proper turret board construction, plenty of scope for experimentation, and no problem having to get a custom-made front panel made up. Thanks for the link! I'm sure I'm not the only one round here who might be interested. [quote name='Subthumper' post='1936' date='May 19 2007, 01:14 AM']I saw someone was asking about valve pre amps on the basstalk site and mentioned the possibility of building their own.How about these? [url="http://www.musikding.de/product_info.php?cPath=103&products_id=1033"]http://www.musikding.de/product_info.php?c...roducts_id=1033[/url] . I've not tried it but a freind did build a couple of their guitar amps and was well impressed.Has anyone tried them? Cheers just[/quote] s