Beer of the Bass

[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.

One thing that occurred to me is that it's harder to drive and park in cities than it would have been 40 years ago - there are more vehicles on the road and parking is heavily regulated. Also, relatively few people have lock-up type spaces to store their gear. If I could always park a van outside the venue and had a ground-floor space that all the bands gear was stored in, I wouldn't think twice about using stuff that was large and heavy if it did a better job. Keeping my gear in my flat and having to contend with city-centre parking, lighter gear makes a lot more sense for most gigs.

[quote name='surdopickups' timestamp='1463050676' post='3048063'] I recommend magnetic pickups whit very low impedance [/quote] Umm, would that be because you make and sell magnetic pickups with very low impedance?

Regarding the red-plating, a good quick check would be to swap the position of the two EL84s. If the same valve still red-plates, it may well be a valve issue. If the red-plating stays with the same socket, it could be a poor connection on the socket or one of the issues Mikey points out.

[quote name='mcnach' timestamp='1462966957' post='3047335'] I can't remember what I paid for them but I guess it couldn't have been much different from my usuals or I wouldn't have felt inclined to try them when I really don't have a *need*. I suspect they'll last a long time at this level of brightness, 'though... If you want to give the ATK a try, just let me know. [/quote] Actually, that could be quite useful - I'll maybe drop you a message. It's hard to figure out strings from reviews alone!

[quote name='fuzzonaut' timestamp='1462976249' post='3047471'] Nice! I have one of those, in a wooden enclosure. It was my first amp with tubes in it. When I had it serviced a few years ago, I got a power amp input installed (at the back). I'd go with this solution, as it also leaves you with the possiblity to use the full amp as well. After using it as a bass amp, I now use it as a "mixer" amp to run (and mix) different stuff (synths, vocals, drone boxes) through the channels. [/quote] I was thinking about only removing the two input channels on the right, fitting a simple (B15n based) valve preamp in their place and sending it's output straight into the power amp. The two channels on the left would still be there, and the three central controls would still work on those. So it would still keep most of the original functionality of the amp, just with fewer input channels. It could also be put back to the original state quite easily, if it doesn't work out. The more I think about it, I reckon this is the route I'll try.

Hmm, I'd been thinking about trying these. My Sadowsky flatwounds are good in an old-school way, but I'll be doing some stuff this summer with a guitarist who likes to be loud, and a bit more brightness might not go amiss. Shame they cost a larger number of pounds than they do dollars!

I've used an Artec "Giovanni" tele bridge pickup which was nice. It's a bit hotter than a standard tele bridge, but not so hot that it loses the tele sound. They're fairly standard vintage style alnico pickups and seem well made. [url="http://www.eyguitarmusic.com/Artec-Custom-PickupVitage-Tele-Pickup1pcs-of-Bridge-pickup_p_1214.html"]http://www.eyguitarmusic.com/Artec-Custom-PickupVitage-Tele-Pickup1pcs-of-Bridge-pickup_p_1214.html[/url]

[quote name='Twincam' timestamp='1462894051' post='3046746'] So how does it sound with a bass? [/quote] It's very clean and quite neutral sounding, though the bass and treble controls aren't very useful for bass as they're centred fairly high. But since I have this nice valve power stage in a compact package, the temptation to put a classic valve preamp in front of it is hard to resist.

[quote name='luckydog' timestamp='1462886012' post='3046625'] Too few opportunities in this life to go into a music shop and ask "Have you got rubber feet?". Each chance should be taken IMO, and the moment enjoyed LD [/quote] Rubber feet? I barely know 'er!

After leaving it sitting for a few weeks, I've got round to doing some work on this. Since the original style screw-mount filter caps are hard to get and pricey, I've made up an eyelet board to take modern axial caps. I've also replaced the bias capacitors and trimmers on the power amp board (as apparently the trimmers failing is a common fault on these) and a couple of drifted resistors. While it was working OK with the original parts and I might have got away without touching it, I want to make it as dependable as possible. I've put it all back together, though I still need to check it over, set the bias and check voltages before I give it a try. Next I need to decide whether I will leave the preamp side of the amp as stock or modify it. At the moment it's essentially a solid-state mixer amp in front of a valve power stage, so isn't as much fun as it could be as a bass amp. I'd like to make a dedicated bass preamp for it, but I could either take out two of the input channels and build it inside the box, or I could make a standalone preamp and add a power-amp input to the back of the Dynacord. Having it all in one box would be convenient and less work, but a standalone preamp could be a bit more versatile...

In this application I would just check the voltage on the caps, and not touch anything until it has dropped to single figures. I have not heard of any working valve amp technician doing anything different, so I'd say this is over complicating things.

Checking voltage between the cap positive and ground is fine IMO, since it's a voltage difference that causes current to flow anyway. I'll often discharge the caps by using a simple clip lead to connect the plate of the first preamp valve (pin 1 on an ECC83) to ground. The caps then discharge through the plate resistor (usually in the 100k ohm range), and the lead can be left in place when working. Obviously, it's still important the check that they've discharged, and in some amps they won't discharge using this method unless the standby switch is closed.

Oops, I've missed the voting! Was going to go for Subsonic Simpleton, XGSX and Camden Rob.

[quote name='Dad3353' timestamp='1462710616' post='3045044'] Go easy, though, folks, these are my pals, although I've not seen 'em for several decades, now. We're dealing with archaeology, here. My favourite style, for instance, is Norse; just wait until it comes back into fashion. I'll be right up there at the pinnacle of 'in-ness'..! [/quote] The colour version doesn't disappoint! In truth, I wouldn't mind a pair of those as stagewear myself, though the matching full-band set is very much an idea of its time!

Never mind the beards, those are some spectacular trousers. Shame it's a black and white photo!

It's nice to see some reviews, but his old-school/new breed distinction seems a bit arbitrary IMO. I'd consider the Chromes and Ernie Balls to be modern sounding flatwounds, which don't thump like LaBellas even after a couple of years of use. I'm using Sadowsky flatwounds at the moment (which are a LaBella variant), which are more old-school than the reviews I'd read had led me to believe. On my bass, they just instantly sound like it's 1968 or thereabouts. It's a cool sound which I do enjoy, but I'm currently trying to decide whether I need to go a step or two brighter and clearer sounding for one of the projects I have planned...

[quote name='Blartfactor10' timestamp='1462613657' post='3044339'] A guy I know in Gateshed makes these pickups, they sound as good as a KnK, but for about the third of the price. I have one on one of my uprights but you will need a pre amp. (A Boss Graphic EQ would do the trick) http://www.ebay.co.uk/itm/J-tone-Big-double-Bass-Pick-up-/201498506263?hash=item2eea3f3417:m:mMv8R28HOczqgXmXPBsADZw [/quote] I also have one of these, and like it better than the Revoolution Solo 2 I had. I think the jack mount that comes with it is a bit ugly, but otherwise it's a good option.

[quote name='herbass' timestamp='1462522805' post='3043678'] Maybe we should get together here in Scotland too! [/quote] Hmm, maybe not a bad idea.

Would two ports of different lengths really have two discrete tuning frequencies, or just a single tuning frequency? I'm more or less thinking out loud here, but my cabs have 3 identical ports. With all three open they're at 50hz, and with one blocked the tuning drops closer to 40 Hz. That makes me think that the tuning frequency is a property of the whole cab/port system and not of the individual ports. If that's the case, wouldn't dissimilar ports still give you a single resonance but just make it harder to model?

If you're attached to the idea of winging it without looking into things too deeply, you could just measure the internal volume of your box, then use this calculator to figure out what length ports would give you what tuning. The open holes you have at the moment will behave like a port with the length the thickness of the wood. [url="http://www.linearteam.dk/default.aspx?pageid=ventcalculator"]http://www.linearteam.dk/default.aspx?pageid=ventcalculator[/url] Most bass cabs are tuned anywhere from 40Hz to 55Hz, so if you shoot for somewhere in that range it'll be an improvement on what you've got at the moment even if it's not completely optimal.

Without knowing what the volume of the cab is, it's impossible to say what tuning frequency you've ended up with, but at a guess, two 4" ports 18mm long would come out much higher than any tuning used in a bass cab. I had a quick play around in WinISD, and it comes out as anywhere from 80Hz upwards depending on the box volume. Such a high tuning is likely to give you a large bump in the midbass (the boominess you're hearing), but will also massively decrease the power handling below the tuning frequency, risking blowing your driver. The port tuning could be lowered by putting tubes in the holes, so it might be worth doing some research to figure out what would work with your box and driver.