Beer of the Bass

After building myself a guitar amp several years ago (which was based on the Fender Princeton Reverb) and tinkering with a couple of other amps in between, I've found that putting together valve amps is something I really enjoy. I wanted to get a couple more builds under my belt to see if I can up the standard of my work, but parts can be costly, so when a friend asked if I would build an amp for him (in an informal sort of way) it seemed like a good idea. After quite a bit of discussion, we settled on the idea of a 50 watt amp based on the old Marshall plexi but with added reverb, and it's going to be in a 1x12" combo cabinet. The reverb is based on the "1-tube reverb" circuit found on the Hoffman amps forum, which is less full-on surfy than the classic Fender reverb but reputedly works well in this style of amp. There will be a couple of small tweaks from the standard 50-watt plexi circuit, which I'll detail as I go along. My parts choice is an attempt to find the middle ground of decent quality, dependable stuff without either going too cheap and compromising quality or falling for the whole boutique snake-oil thing. Once I'd got most of the parts together, I started assembling the board which the smaller parts are mounted on. Marshall would have used turrets for the wiring, but I'm used to working with eyelets so I used those, mounted on FR4 fibreglass material. There are still a couple of resistors missing here which I managed to leave off my initial parts order. While waiting for some more parts to arrive, I got my chassis prepared with the necessary holes. I'm not much of a metalworker, so I bought a ready-made blank chassis rather than folding my own as some builders do. I did pick up a couple of old chassis punches on eBay which do a much better job of the 3/4" and 1" holes for the valves than drilling would. The hole for the IEC mains connector is always a bit tricky without specialised tools. I drilled out the corners, chomped out most of the material with a hand nibbler and then filed it out to the correct size. This left a few scuff marks around the hole, but thankfully those are on the back panel. Next up came fitting the valve sockets and doing the heater wiring between them. The layout of this affects how quietly the amp runs, so I've tried to be careful about keeping them twisted together and routed correctly. I have deviated a little from old style Marshall construction here - I've avoided looping wires around the preamp sockets as I've read that this can induce hum. Here's the chassis with the transformers mounted on top. I've used Dagnall transformers from Modulus Amplification as they were a reasonably priced option but are good enough for Marshall to use in their expensive handwired reissues. The reverb transformer is the exception to this - it's an unbranded generic one. From left to right are the reverb transformer, power supply choke, output transformer and power transformer. With all of that iron, it weighs a bit! At the moment I'm in the process of doing the off-board wiring underneath the chassis, so there will be more to follow...

[quote name='wateroftyne' timestamp='1465371120' post='3067545'] That's the thing - when I think of 'heft'. I'm not thinking about bass. It's a solid, low-mid backbone. It's all so confusing :-) [/quote] I wonder if this interpretation of the H-word might be that subtle form of distortion that valve amps do well, as do certain speakers? I mean the sort that adds some extra harmonics to the sound (so adding low mids on top of your lows) but stops well short of sounding gritty or dirty and would still be thought of as a clean sound in any musical context.

[quote name='luckydog' timestamp='1465389349' post='3067745'] It's sad, Buddy sure had some personal problems. That approach is just plain wrong, but maybe the band knew he had problems and put up with it ? Otherwise, fair chance half the band wouldn't have bothered with the second set, or Buddy would have regularly needed surgery to remove a drumstick from his a*se between sets Displaced anger, maybe he wasn't happy with himself for some reason (not necessarily real or to do with drumming ?), dunno amateur psychology 1/2 hour? Sad stuff really...... [/quote] Dave Panichi (the bearded trombonist he's ranting at towards the end of the recordings) said that Rich was guaranteed to kick off after seeing his wife, any time his dope ran out or when there were guests on the bus to show off in front of. So yes, it does point at the rants being triggered by issues other than the performance. And Panichi wasn't actually sacked after this altercation - he says that Rich rarely followed through on any of his threats. I wonder if Panichi even shaved in the end? Although Rich was one hell of a drummer, he does come across as rather a pathetic figure off stage (again, IMO).

I'd walk if an employer tried to talk to me like that, and I have done so before (not in a musical context - it was an Italian restaurant where the proprietor tried to copy Gordon Ramsay's management style, minus his culinary flair). Perhaps there are a few people who get by in that kind of environment, but many will get out at the earliest opportunity. Contrast this with how Duke Ellington managed his band. Charles Mingus wrote this after being fired; “The charming way he says it, you feel like he’s paying you a compliment. Feeling honored, you shake hands and resign.” IMO Ellington was the better bandleader.

There are a couple of string shops in Edinburgh which tend to have some basses, Stringers on York Place and Gordon Stevenson up in Bruntsfield. But neither keeps a huge stock, so you'd probably want to phone first. It's hard to try out basses in Scotland! What sort of thing are you looking for, and what's your budget? If you're doing mostly rockabilly, a decent old German or Eastern European plywood bass might be a good option, and they do show up used now and again.

Ah, I went to see Bill for a small repair last year and he showed me the plans for a new bass he was starting. One of his would be way out of my range too, but I'll definitely give him a call the next time I need repairs or setup.

I hope you've not made the trip to Glasgow just to visit the Violin Shop. I don't think they open on Sundays.

Were these in Varsity Music? If so, run a mile! Nashville is a label they put on the most basic Chinese instruments they seem to buy a container load of every few years, and the double basses I've seen in there have been awful, genuinely worse than anything else I've seen on the market. They had one in their window with no soundpost for a couple of years, with the top slowly collapsing! If I was looking for a good value bass at the moment, I'd either keep hunting for a used instrument or order something from Thomann or Gedo and keep some cash back to have decent setup work done locally. Alternatively, it might be worth ringing the Violin Shop in Glasgow - it's a while since I've been in, but they've often had some not too expensive used instruments and I think they also carry the Stentor basses which are probably one of the better cheap new basses stocked in the UK.

[quote name='LukeFRC' timestamp='1465044875' post='3064912'] I do wonder if BareAssFace Inc. from Pennsylvania or Dortmund's BareGesicht GmbH would get the same kind of response on here..... [/quote] I think I've said this on a Barefaced thread before, but I reckon some of the attitude towards Barefaced on this forum is because anyone who has been here for a while remembers Alex posting about his DIY projects before there was a company at all, and people have trouble adjusting to them being a professional outfit now. It's like the old Scots "Kent his faither" putdown. Small companies who had their growing pains elsewhere and arrived on Basschat fully formed don't get nearly the same treatment.

On John Entwhistle and bass tone, does anyone else feel he lost his way a little once he got to the point where he could genuinely have any rig he could think of? I mean, Live at Leeds is fantastic, a real benchmark of rock bass for me, but later on when the Alembics and Buzzards, effects and huge multi-way rigs came in I enjoy his tone far less, though the playing is still great.

[quote name='EBS_freak' timestamp='1464716573' post='3061796'] Why he need so many cabs? I thought these Barefaced cabs were loud? [/quote] I guess he's running some sort of wet/dry or clean/dirty multiple signal path setup?

I was looking at the Celestion website trying to choose a guitar speaker when I noticed that they have a couple of new bass drivers, the Pulse10, 12 and 15. Since I finished my cab build a while ago, I haven't had more than a cursory glance at the specs and they don't seem to be a huge departure from what's out there already, but it's interesting that they're coming out with new models. Here's the 12: [url="http://celestion.com/product/157/pulse12/"]http://celestion.com/product/157/pulse12/[/url]

If it's been damaged that easily with a water-based cleaner, it might be french polish, which gets cloudy white-ish marks when water damaged.

If it's one of the old models (pre-JCM800), it has two parallel input channels which are voiced differently - one brighter and one bassier, each of which has a high and a low sensitivity input. Many players like to link the two with a patch cable and then blend them with the volume I and II controls. Most models can run 4, 8 or 16 ohms with a selector on the back panel.

I've recently changed out the filter caps on my Dynacord head, but one of them had failed years ago and been sloppily replaced with two marginally rated caps positioned right where the hot air rises from the power valves, with the wiring to them running across lots of the audio wiring. So it felt quite reasonable to sort that and refresh the ones in the bias supply too while I was at it. I had a bit of a learning experience with one particular amp I had several years ago. It came to me with a loud hum - first I changed the main filter caps to no avail, as it turned out to be the one in the bias supply. Then I ended up chasing a crackling noise in the power amp. I had replaced most of the resistors in the power amp and replaced and re-wired the output valve sockets before I figured out that the noise was from one of the power valves, which I had just assumed must be OK as they were new. So, I had a quiet, working amp at the end of it but it occurred to me that I had replaced many more parts than might have been necessary, and someone with a bit more experience would have been more methodical and addressed those specific issues right away.

I wouldn't cut up the combo cab, but if you were to build a head sleeve for the amp chassis and stash the combo cab away somewhere then it seems like a reasonable plan.

[quote name='Happy Jack' timestamp='1463583685' post='3052555'] Apart from putting the wrong pickup in the wrong position, of course. [/quote] I think it was made for a bridge with much narrower string spacing, and if the right bridge was fitted the strings would align with the pickup just fine. It's kind of an eccentric design, but (with the exception of Fender) what wasn't in the mid 60s?

I'm going to guess that the bridge is not original, as the strings are badly mis-aligned and it looks like a well built instrument otherwise. With that chrome cover it's hard to see if anything has been changed underneath. The tuners look cheap by modern standards, but I'd guess that the choice of hardware available to small builders at the time was nothing like what is available today. I've no idea about the collector value of this sort of thing, but it does seem that Allen was a well known luthier who made instruments for some significant players.

[quote name='Twincam' timestamp='1463573833' post='3052431'] The thing is old caps can work ok but for how long? And people think there serviced amp is going to be good for another 20 odd years which it won't be. The other thing people don't seem to test for is a caps esr rating which is from my understanding a better way of evaluating a cap. [/quote] I guess there's also the question of how much bench time is really justified for an amp of a given value, bearing in mind that anyone who isn't into DIY pays by the hour to have their amps worked on. Perhaps on premium-valued vintage gear it would be worthwhile to test every part, but I've always had the kind of B-list valve amps that would be hard to shift even for a couple of hundred quid (although I note there are some people on a mission to slowly push up the prices). Many of those are good, solid amps, but a few hours of time from an experienced tech would be getting close to the market value of the amp. Taking a pragmatic approach to that sort of lower valued gear, it may make more sense to assess the functionality of the whole unit and deal with any problems as they occur.

Regarding things like replacing electrolytic capacitors on old amps, I found it interesting reading through John Chambers' website. He's an amp tech with decades of experience and the site is a mine of information for anyone interested in these things. I noticed that he does not routinely replace capacitors in old amps unless they have visibly deteriorated or the amp isn't working correctly. This seems quite different to the prevaling wisdom nowadays, but it's evident that he knows his stuff. I do tend to go through any older amp of my own and replace them, but I realise this is like the guys who strip down old Morris Minors in their garage - tinkering as an end in itself.

It might help to go down a gauge, as changing from rounds to flats of the same gauge usually requires at least a truss rod tweak.

[quote name='mcnach' timestamp='1463358696' post='3050767'] If they're similar to the S112, I'd say light [/quote] They're a bit heavier than the S112s as the boxes are about 10% larger and birch rather than poplar. But still nothing like the 30kg Peavey 1x15" I used for a couple of years. I guess using a mixture of lightweight and old-school gear would still be a yes to using lightweight gear, so I've voted accordingly. At the moment there doesn't seem to be a big difference in age distribution between the two groups, which is interesting.

Hmm, how do we decide if we're a yes or a no here? I have a micro head and lightweight 1x10" for the situations where that works, but at least some of my next few gigs will be with a valve head and a couple of ceramic 12"s. I'm not sure which box to tick!

I've now got it reassembled and fully working with the new filter caps and a fresh pair of JJ E34L valves. Here's a gut shot before the valves went in - it's tightly packed in there! After checking the voltages and setting the bias, I had a play with one of my DIY 1x12 cabs. It's a nice sounding little rig, though I haven't had a chance to turn it up yet. I'm pleased at how quiet it is in terms of hiss and hum - I've had modern micro heads with more hiss than this! I definitely need a more bass guitar voiced preamp though, as I like to boost the highs a bit to bring some articulation out of my flatwound strings. The treble controls on this work so high up that I can barely hear a difference when playing with a tweeterless cab. It looks good with these cabs too - I think it will be fun trying it with the pair of them next time I jam...

It's definitely a bit of a niche interest, and then there are further niches within the genre. I mean, I would cheerfully join a band that was influenced by some of the eccentric 70s UK prog bands, but some of the music that gets called prog now sounds almost like a metal sub-genre and I don't really enjoy that stuff.