Beer of the Bass

Can you tell us much about the preamp, even just which valves it uses and what controls it has? Depending on the circuit it might be necessary to add an extra active stage to the preamp to lower the output impedance. A good tech would be able to do this with a high voltage FET if the power supply and chassis space can't support another valve, similar to the circuits often used to drive effects loops.

[quote name='mcnach' timestamp='1453992004' post='2965084'] ha ha yes... portable is the name of the game... the recent game of musical chairs has only come about by a need to reduce bulk further... I used to have lots of storage space, then I had lots more... and now I have very little, and the situation is unlikely to change until much later in the year, so I am taking the opportunity to find ways to reduce bulk in general. So far so good, it led me to discover the TKS S112 cabs and I love them. They don't have a huge sound or anything but... there's just something about them that I really really like. I have to ask Tommy what speakers he puts in those. [/quote] If you get curious enough you could always pop off the connector plate at the back and stick your phone camera in the hole (with the flash turned on) . I think it's likely to be the Eminence Beta 12, as TKS have said they use Eminence and it's a 250 watt rated ceramic driver, with specs that very closely resemble TKS's published specs when you model it in that size box. But I may be off the mark with that one! [quote name='mcnach' timestamp='1453992004' post='2965084'] How are yours coming along? [/quote] A bit slower than I anticipated at first, the boxes are assembled but I still need to do the baffles, round off the corners and paint them. I'll probably get a bit of a move on next week, as I'd like to use them for a gig in a fortnight. There's a thread in the Build Diaries section. If they do turn out to perform similarly to the S112s, you're welcome to try them stacked up with yours with the series/parallel cable.

I was going to say Ampeg SVT (or the cheeky Bugera clone) but I guess you want something a bit more portable!

I did a bit more; the bracing is now glued in. In hindsight this would have been much easier if I had done it before gluing the backs on - I'll know this next time! It took quite a bit of sketching on paper to make sure that the bracing, ports, speaker and handle bolts don't occupy the same spots, but I managed to fit it all in there. The bracing has easily been the most faff-y part of the build so far, so I could see the appeal of using a heavier plywood and less bracing if you want an easier build. Next up will be fitting the flanges to attach the baffle, and preparing the baffles. I've also picked up my paint, grille cloth and hardware. They will be Tuff Cab Turbo Blue, with this grille cloth; [url="http://www.tube-town.net/ttstore/Tolex-Grillcloth/Grillcloth/Grillcloth-Tube-Town-Silver-Line::6592.html?language=en&MODsid=rlemtoaog15ncl5uki2n8l9hr7"]http://www.tube-town...ncl5uki2n8l9hr7[/url] I went with this supplier because I needed some amp parts from them at the same time, so it was convenient to only have to pay one lot of shipping. In the flesh the silver stripes are quite sparkly, but it the rest it is black rather than the grey of Fender grille cloth. I think it'll look quite classy with the blue finish and chrome corners.

It's a funny one, there are certain posters who get my back up on some subjects, and sometimes make me question why I'm here, yet often those same posters turn out to be quite insightful on other topics. You may or may not know who you are!

Looking good so far! I haven't seen that style of mould construction before - are you working from a particular method or is it something you've come up with? I have accumulated wood and bits for a mandolin build, but not quite got around to getting started on it yet, so I will be going through some of these same processes.

[quote name='EssentialTension' timestamp='1453659871' post='2961509'] Hardly sounds worth worrying about then. [/quote] Indeed. If what we call a dead spot is the effect of neck resonance on the tone and sustain of notes in a certain range on the instrument, I'd say that it's just a part of the sound of the bass guitar as we know it. Just as an example, James Jamerson had a very noticeable dead spot on his bass which you don't even need isolated tracks to hear, and that's one of the archetypal sounds you can make with a Fender bass. Admittedly, his heavy flatwounds and foam mutes make it stick out even more - they can be moved around or lessened somewhat by changing strings, hardware or setup. [quote name='EssentialTension' timestamp='1453659871' post='2961509'] Not as entertaining as 'Well, [i]all [/i]Fenders [i]always[/i] have dead spots'. [/quote] I guess my point is that it doesn't make sense to assess instruments in terms of a binary "does this bass have a dead spot, Yes/No?" approach. It would make more sense to ask "Is the dead spot on this bass in a place that bothers me?". Often they can be minimised to the point where they are not noticed in use, but that doesn't mean that they're not there at all - the neck will still have a resonant frequency which can only be moved around or damped to a limited extent without substantially redesigning the instrument.

Literally every bass guitar I have ever spent time playing has had a dead spot to some extent - where one or two notes, usually on the G string between C and Eb, have slightly lesser sustain than the surrounding notes. That has included a couple of neck-through instruments too, one 32" scale and a couple with graphite neck reinforcements, USA and Japanese made instruments and a couple I built myself. If you're lucky, the pitch of the resonance falls in between two notes so that the effect is less strong - these are much easier to live with. If you're unlucky, it falls spot-on one of the notes. Listening carefully to the effected notes, it sounds like the fundamental dies away quickly leaving the harmonics above that ringing. I do think that they can be more noticeable with flatwounds, and neck relief also seems to have an effect. So I find the "Well, [i]my[/i] Fenders never have dead spots" response of some posters entertaining. I don't think I have unusually sensitive ears and nor have I had exceptionally bad basses, so the issue must be that we don't all identify or define "dead spots" in the same way.

I did a little more this afternoon. First I had a look at the joints that I'd glued up last time and went round with a block plane levelling up anything that was not quite flush. I'm quite happy with how neatly the joints have come out and I don't think I'll have any issues with air leaks from them. The screw holes will be filled and levelled later. Then I cut the offcuts into 40mm wide strips for the bracing. I am cadging Phil Starr's bracing approach from the 1x12" design diary, as I thought this would save me the trial and error of trying to work out my own bracing scheme. Cheers for that, Phil!

Similarly, I was asked to turn down my 15 watt 1x10" guitar combo in a 900-capacity rock-oriented venue (Studio 24 in Edinburgh), when I'd had the volume turned up to about 4 on the dial. I'm not sure what they do when people use the house backline 4x12" rig. There's a little basement venue I've played a few times which has a 50 watt 1x12" combo as the house bass amp, and I've been asked to turn that down too! You can get away with surprisingly little amp in situations with full PA, though less so when the PA is vocal-only or monitoring is inadequate.

I don't know, TBH. That's why it would be interesting! I do wonder how big a factor expectation bias is though.

It would be an interesting experiment to glue a couple of housebricks inside a 2u rack case with a bog-standard ICEpower module to see whether bass players coo over the "heft" of the sound!

A little more progress - vane braces glued to back panels: Back panel glued into cabs. Nice healthy glue squeeze-out here! I've used some woodscrews through the outside to hold things together (in lieu of clamps) while gluing - I'll remove these and fill the holes when the glue is dry.

The concept is a good one, since I find Musicman basses aesthetically pleasing and they make lovely necks, but I've never quite got into the whole active thing. So I guess these are aimed at people who feel the same way. It would have been nice if they had a few more nods to the classic stingray/sabre style visually though.

[quote name='Twincam' timestamp='1453394620' post='2959129'] Very very cool. Any pics of its internals? [/quote] I haven't taken any internal pictures of mine, but there are some of the same model here: [url="http://www.radiomuseum.org/r/dynacord_eminent_ii_2_t.html"]http://www.radiomuseum.org/r/dynacord_eminent_ii_2_t.html[/url] It's quite a tight layout in there - servicing it will be interesting...

I've always enjoyed having interesting old valve amps around, but I've been without one recently. I had a smaller Dynacord Bass King T for a little while, so when I spotted this Dynacord Eminent II on eBay, I decided to go for it. It's an unusual design; intended as a PA mixer amp, it has transistor preamps with a valve phase inverter and power stage. Even more unusually, it runs a high plate voltage of around 750 volts in order to achieve an output of 80 watts from a pair of EL34 valves, which would typically be used at around 400 volts in a 50 watt amp. They were made in Germany from the late 60s to the end of the 70s - this one is dated May 1978. It has the benefit of being very compact for a valve amp of this output and having a perspex front panel which is illuminated in green when switched on - I'm a sucker for that sort of kitsch! I was fairly lucky considering that I bought it unseen. It arrived in working condition; there are no issues with hum or noise, it has the correct fuses and the valves are not red-plating or microphonic. The valves are a Telefunken ECC81 and a pair of Hoges EL34, which I gather are re-badged RFT EL34s. I haven't had the chance to check voltages or bias yet, but I will do that. While the amp doesn't seem to require troubleshooting, I still intend to replace the filter capacitors for the HT and bias supplies and replace the bias trimmers with more modern types just to make it a little more reliable. One section of the can capacitors has been disconnected and replaced with a pair of lower voltage rated capacitors in series, though from the appearance of the capacitors this must have been done more than 20 years ago, as the replacements were made in West Germany. I have only had a quick play through it so far, but it sounds good - very clean and clear. The input impedance is low by modern standards so it can sound dull when plugging a passive bass straight in, but a simple buffer such as a Boss tuner on bypass sorts that out. I might add a direct input to the power amp section so that I can build a B15n style preamp in a small box to use with it - this feels less invasive than replacing the preamp section of the Dynacord (which I've heard of other people doing). The cab in the photo is a small DIY 1x10" which I use for quieter settings, though the Dynacord will mostly be used with the pair of 1x12" cabs I am building at the moment.

I think the big neck is to be expected if they're going for a pre-war sort of feel. My 1936 Kalamazoo archtop has a neck so big that I had great difficulty finding a capo that worked! I have to use the cheap nylon strap kind as nothing else will fit...

I stuck my head in the Cash Converter/Cash Generator place just down from the Queen's Hall today, and they had a 90s Peavey Mark III head in very clean looking condition for £44.99. I don't need it, but if anyone in Edinburgh is looking for a cheap backup/rehearsal room/house backline sort of amp I thought they might appreciate the heads-up.

A little more progress; they're starting to look box shaped. I'm using ordinary PVA woodworking glue, with screws through the corner batten because I don't have many clamps. I used 20mm square softwood in the corners, largely because it was in the bargain bucket at Wickes and the other sizes were full price. The back is going to be glued in, but I'll keep the baffle removable, with a 20mm wide flange along the inside for it to screw to which will be sealed with gasket tape. I need to take about half a mm off one end of the back panels before I glue them in, as it turns out they're very slightly oversized. I might fit the vane braces to the back panels before gluing them in, as it would save some faffing around in a confined space. The back panels are a very snug fit, so I reckon I can get a decent glue joint without using battens along the back edges. Henry the hoover gazes on in admiration:

My double bass has at least 100 years on it and has had years of running repairs though never a full restoration job. If it gets scratched or chipped I'm barely going to notice and if anything bigger happens insurance should cover the repairs. I like the thought that it's been a useful, working instrument for so long, so I try not to be shy about taking instruments out and using them.

What's the status of Picato strings at the moment? I know that Innovation double bass strings, which were made in the Picato factory, have had availability issues recently because the factory was closing. They have said that Innovation production will continue at a new site, but I don't know what that means for the Picato lines. Perhaps Daf Lewis could clarify, since he has worked with Innovation/Picato.

Bits of plywood! Left to right are my top/bottom, sides and baffle/back pieces. I ought to take some more photos than this, but this morning I did some marking out and cut the corner battens to size. Hopefully tomorrow or Tuesday I'll have them looking like a box, then it will be on to bracing and cutting out the baffles. I'm using Edinburgh Hacklab, a shared workshop space, as I don't have the sort of work space to do this stuff at home.

I reckon you're thinking of the Fearful cabs, which are available as plans for DIY'ers or from approved builders, and do have some design similarities with the earlier ranges of Barefaced cabs. [url="http://greenboy.us/fEARful/"]http://greenboy.us/fEARful/[/url]

[quote name='Manton Customs' timestamp='1452860718' post='2954150'] That's probably a good idea if you buy an unfinished one - and it need not be Fender. A Nitro finish will naturally relic/age much nicer than the Poly on most of the alternatives. 90% of companies that offer a Nitro finish these days are actually Nitro sprayed over a Poly base coat, so they will not age and check in the same way old finishes do. [/quote] I'm not massively knowledgeable about old Fenders, but I'd read that they have been using a thick polyester sealer as a base coat since some time in the 60s at least, so finishing that way might be appropriate for a 60s style instrument.

Yes, there's only about 1dB difference in the size of the midbass bump between the two tunings, which is going to be very subtle if I can hear it at all. There isn't much difference in the steepness of the roll-off below that either. I can fit three 64mm ID ports in a box this size at 50Hz (four ports work out longer than the box depth) and it looks like I'd be likely to exceed the driver Xmax before the port air velocity gets high enough to be problematic. My old cab which I wound up selling (which these are replacing) had similarly low mechanical power handling at 30Hz and was even limited at 40Hz, but in practice this didn't cause me problems with the amps I use and volumes I play at.