Mr. Foxen

If you are using the valve head, then the smart power cabs probably aren't the ideal thing, they trade sensitivity for size, so the cost of being small is they want more power for volume. Only big is true when you have the limits on max power. With the terror bass, probably happy with those cabs.

[quote name='Subthumper' post='1127835' date='Feb 14 2011, 11:53 PM']Hi, interesting you should say about the multiple or cascaded gain stages as I recently serviced a Burman guitar amp with such a pre amp. Its a completely different way of getting your sound as it is possible to affect the tone and not just the gain and drive of the circuit by adjusting the three gain controls. Sounded fantastic and got me thinking it would be fab for a bass pre amp (if maybe with a little less gain and tweeking of the tone stacks). Not sure what the Burman bass amps had in terms of controls so maybe one the Burman owners could fill us in. Sorry to hijack the original thread but had to chip in. Cheers Just[/quote] I plan on using my Burman for bass, but mostly the top end stuff. I think the Burman thing is adding control to various steps of the gain stages, that otherwise would be fixed, it sort of removes the 'signature tone' of an amp and gives loads of flexibility. A mate used a Pro4000 for bass, and it is the same control as my 70w one, first gain and 2 band EQ, then the 3 gains, then a three band EQ, you can patch in after the first gain/eq.

[quote name='Roland Rock' post='1125037' date='Feb 12 2011, 03:30 PM']I'm finding this very interesting and informative. Sorry if it's deviating from the OP, but I have another question: If you have a signal which is getting progressively dirtier after driving the pre and power sections, why is it not possible to cut the volume with the master volume and still achieve the same dirty tone? Is this because it's also necessary to 'open up' the power valves (with master volume) to achieve the power amp drive? Basically I'm unsure as to the relationship between the master volume and the power section.[/quote] The master volume is generally just before the power stage, at the end of the preamp, the power valves clean limit is the 'watts' rating of the amp, and you generally have to be asking more of them than that before they dirty up, so with a SVT that gonna be somewhere over 350w actual output, which is very loud, loud enough until you get a very large venue (large enough for a decent sound man), you amp sound is going to dominate it's sound field. I am tending towards around 100w rated amps for my dirt, and even then it is mostly preamp dirt, got a 70w incoming that should give me the rest.

There isn't only one flavour of dirt. The best drive sounds come from adding dirt at multiple stages a little bit at a time. If you feed an amp a dirty signal, it can either make it the same but louder, or distort it more, making an increasingly dirty signal at each stage. The power amp distorting is another link in the chain, but a necessary step in getting that to drive is hitting it with a lot of signal that it correspondingly produces a lot of signal, and thus, generally, a lot of volume, and with the power stage, you don't have much by way of means to cut that volume.

[quote name='Happy Jack' post='1124988' date='Feb 12 2011, 02:42 PM']Fascinating. So can you only get "that classic overdriven valve sound" by pushing the output valves really hard? That can't be right, surely, or my Orange Terror Bass (valve pre / SS power) wouldn't sound the way it does.[/quote] That is just preamp drive, doesn't have the same compression effect that power amp drive does, and the drive is 'girthier' as well as you can describe it in words, you kind of have to have the bass in hand to appreciate it, because it is compression, and this not immediately audible. Basically to get that distortion you need to be hitting valves with more signal than they can take, rather than just opening them up. Each 12ax7 has two stages inside, so single valve drives either run one into the other so the second distorts, or have some solid state clean boost first. Really thick drive sounds are loads of small gain stages, and the power section drive is another on top

Not Doom.

[quote name='slave' post='1124558' date='Feb 12 2011, 12:46 AM']Yeah - I've seen some of that too. I wonder how much of that is from a tech. point of view (difficulty to work on) similar to a mechanic, or whether it's about overall design? Many people love how an Alfa goes, but I'd never own one....... A tech I met a while ago was pretty prickly about the big Fender tuber, and wasn't a big fan of the SVT either. My guess was because of weight and difficulty to work on? [size=4]But I'd love to know of the ones that are thought to be poorly designed with longevity in mind.[/size] I really don't want an amp that'll last 5-10 years, and then have to have a load of work done to it because a pcb has melted/warped to to heat issues.....[/quote] [url="http://www.chambonino.com/workconst.html"]This site/guy[/url] has breakdowns of tech work in amps, so is a pretty good source for what makes things good or annoying.

Mastering for vinyl is an art in itself. Some people will have a preset thing that does a generic job (compress, make the bass mono), but a proper job involves a lathe thing about the size of a car. I'll ask about the good place I've been recommended before.

Fender Bassman preamp mind. I've tried one but it was horribly let down by the nasty sealed cab in the music shop.

[quote name='simon1964' post='1116414' date='Feb 5 2011, 12:21 PM']That looks stunning! Where did you get the chrome scratchplate?[/quote] [cough][url="http://basschat.co.uk/index.php?showtopic=114335"]See here also.[/url][/cough]

[url="http://greenboy.us/fEARful/headcase.htm"]There is this which is a mid/treble enclosure.[/url] Not really worth pairing with Compact, better off with a dedicated sub. The Big Twin and other midrange driver cabs fill the need, so no point adding to the compact.

[quote name='geoffbyrne' post='1121585' date='Feb 9 2011, 05:15 PM']Another important point often ignored in threads like this is the importance of a matched Phase Invertor. This tube switches the signal from - to + & back again to go therough the power amp. It uses both sides of the valve. If each side has a different value the sound coming from the amp will sound rough, but if both sides are matched - or pretty damn near - then you'll get a nice smooth tone.[/quote] On the Peavey Windsor heads there is a knob that unbalances the phase inverter for that sort of distortion, so it might be desirable in some circumstances.

Not really worth a new thread, can someone let me know if the drive on these agrees with tweeters?

[url="http://www.newtonestrings.com/"]These guys[/url] made my 0.075 to 0.145 set.

[quote name='Phil-osopher10' post='1120886' date='Feb 9 2011, 01:19 AM']On another note: What is the purpose of mesa boogies 'passive radiator' on it's scout combos? Would I be right in thinking it is a touch gimicky?[/quote] A passive radiator is another means of tuning the cab, like a port, but they can be adjusted a bit more by changing their weight. I'm not sure of what advantage other than that they have, much more complicated than a port. As for cabs influence on 'tone', most of the midrange part is determined by the speaker, and that bit is where your ear pics up most 'tone', but the reflections inside the cabs if it isn't lined properly can carve out chunks. The box and porting (the winISD stuff) is mostly below 200hz, so is more 'bottom end' than 'tone'.

[quote name='bozzie' post='1120168' date='Feb 8 2011, 03:24 PM']id be interested to see how this thread develops, as in the past i've always liked the sound of single 15" speakers, however as I'm on the lookout for a cab, I'm considering other configurations. The favourite so far has been the markbass 4x10, but like I said I'm still looking. The 2x10 and 1X15 sounded good (ashdown abm), but i wasn't so sure about the 2x10 configuration on its own.[/quote] I don't see it going anywhere far, or good. The bit where it is made clear there isn't a link between speaker size and the sound in front of it has been covered already, so there isn't much else to say. Find a cab you like the sound of, add more the same until volume requirements are met.

[quote]Due to wavelength, drivers of different diameters beam (become unpleasantly directional) at various frequencies. Here's a table of various driver sizes and the frequencies where their pistonic movement causes beaming: speaker beaming limit ------- ------------- 18" 903 Hz 15" 1052 Hz 12" 1335 Hz 10" 1658 Hz 8" 2105 Hz 6" 2672 Hz 5" 3316 Hz 2" 6840 Hz 1" 13680 Hz[/quote] That is the only bit directly affected by diameter.

Sansamp isn't really the thing for eq rather than colouring. Vt has a fair bit of control, and plenty of drive for the rock stuff.

So 'This is a guitar' tape instead of 'fragile'.

Like this:

Do a search for the term 'thiele' and you'll find lots of threads about matching speakers to cabinets. Sounds like the cab is tuned too high for them, extending the port might help some, can't recall what sort of ports these have, if it is a tube, use something to telescope it.

[quote name='BigAlonBass' post='1117501' date='Feb 6 2011, 11:42 AM']with the voids filled with shredded cardboard[/quote] Bah, I hate this, shredded card or paper or chips make a terrible mess when unpacking, and unless you really cram them, they settle. If you do cram them, they proper explode out when you release them. Shredded card is heavy too.

Since that other thread was disappointing in regards to actual info on how to pack a bass, share your tips here. I've send a fair few basses now, and done ok for damage. Pack like the courier is planning on damaging it. If they are OK with shipping with the neck off, do it. Shorter, but still weird shaped package. Bubble wrap the neck and body separately, then attach them together, in such a way what hardware isn't going to scratch or gouge, and with the tuners facing 'inwards' as it were, they are a weak point. I tend to masking tape the neck plate and screws in the neck pocket. It also makes it look a bunch less like an easily Cash Convertible musical instrument. Masking tape the innermost packaging rather than parcel tape, no stickiness on the bass (I often masking tape rolled up bubble wrap to key areas, before the wrap around part). Also means easier to open up, less temptation for risky sharp things close to the bass. Take off the strap pegs. A good dropping will hammer these into the body wood, best taken right off. Wrap a bunch of packing and some card around the machine heads, then pack the whole thing over that, they are such a weak point. Cling film is really handy for securing things together, but it isn't protective against much. Cling filming various parts together is great, but they still need some sort of impact protection. Loosen the strings, and put something between them and the body/neck, they can fairly easily get hammered into the frets or other hardware.

Microphonic valve. Tap them with a chopstick when it is on. Is most noticeable if it is one early in the signal path, as there is more gain afterward, so if you have no spares, can do some swapping to lessen the problem.