Mikey R

This explains the differences rather well: http://www.youtube.com/watch?v=5LMp0qw0FYw

Ok, its only the front page of their site thats knackered at the moment, the product pages still work (google is youre friend) [url="http://ashdownmusic.com/products/1/Bass-Amplification/1/Valve/10/CTM100/"]http://ashdownmusic....alve/10/CTM100/[/url] Yep, two KT88s rather than four EL34s. Really want to try one!

So has anyone been able to compare the Little Bastard to the bigger CTM amps? Do they have a similar pre-amp? Im pretty certain most of the growl of this awesome little amp comes from the EL84s, so using KT88s would reallly clean the amp up and really change its character. Im surprised they didnt offer an EL34 amp to cash in on the extra grittiness we've come to expect from those valves. EDIT: Just went to look at the http://www.ashdownengineering.com website, and I got this: Whats up?

hey, everyones saying these are super clean and transparent. does the valve really do anything in these amps?

[quote name='RandomBass' timestamp='1379274243' post='2210757'] I find the exact same with the bass shift switch. Nice, ain't it? [/quote] The character of the amp changes massively as you push the power amp, i find you need to play with the tone controls as you change the master. I really is an excelent amp for hard rock and metal, im not sure how it would cope with something smoother.

[quote name='RandomBass' timestamp='1377104449' post='2183436'] I'd guess that pairing would sound very much like the LB30 drophead combo. I do know that my LB30 and BF Compact sound very sweet together. Question for you - do you find the LB30 Mid-shift and Bright switches do very little (if anything) tonally? I get a big change from the Bass-shift switch - much more midrange in the up position. Basically nothing from the Mid-shift, and a very slightly perceptable change with the Bright switch. Would be interested to hear your findings. Cheers Geoff [/quote] Ive got the exact same setup, I find the bright switch makes a huge difference, i guess its for less hifi cabs as it sounds pants with the bf. The mid switch does make a small difference, but not much. I only just started liking the bass switch, with it off i get a Steve Harris kind of tone, switched in and cranked up it becomes huge!

I agree with the above - in terms of cost, no way. You will also need to invest in a whole load of tools, you might make a few mistakes and have to do a bit of rework with fresh materials, etc. However, I think the BOM cost of the bass in my avatar was around £80 all in, with pickups, bridge and tuners from ebay. Im not telling how much I spent on tools whilst building it

Ive had a bit of a noodle around on it this morning - plugged straight in to my Ashdown LB throught the Barefaced Compact. I was initially struck by how rounded the Fender is, the tone is very mellow. Its also surprisingly easy to play with medium action. Notes sound with plenty of control, which is always something I look out for. Some Fender type instruments can feel a little 'sloppy', like there is a slight delay between playing the note and the string starting to sound, this bass has none of that. I did a few A/B comparisons next to my blue P type bass, which is a very agressive, snappy instrument. The blue bass is very fast to play, with plenty of tonal variation depending on how you pluck each string, but that makes it a wholly unforgiving experience - you mess up a note, you'll know about it. The Fender, on the other hand, gives a much more balanced playing experience. Ive optimised the setup of the blue bass to play best around the 5th to 7th fret, as thats where I tend to find myself playing the most. There are a few buzzes above and below that position, nothing that really comes through the amp but you can feel them under your fingers. Its a little unfair to compare the Fender with the blue one, as the action is totally uncomparable, but as it is the Fender plays well at every position. I did miss the upper frets on some chord playing - the blue bass has 24 frets, its odd to think how much I uses the upper end of the neck. Maybe its just psychological, and I'll get used to it, but even if Im not using the dusty end in any songs, its nice to know its there. More to follow... EDIT: Forgot to say, even though this is an 8 year old instrument, it looks like its had a sheltered life living mostly in its original Fender flight case. No scratches, its not even chipped around the headstock like most guitars are.

In a moment of weakness today, I took home this beauty. Its a 2005 MIA Fender Jazz, black on black with a rosewood board, currently completely stock but ripe for modding. Frets are clean, action is a nice medium, its a really good player with classic Jazz tone. I'll play it for a while and decide if its a keeper. If I keep it, it'll likely get a high mass bridge, a pair of super hot pickups wound by a local friend and some clever homebrew wiring. Theres tonnes you can do with a jazz plate!

[quote name='RandomBass' timestamp='1376892205' post='2180323'] This is the link I found on Talk bass, via a quick Google search: [url="http://www.captnmoto.co.uk/Stats/LB30_Schematic.pdf"]http://www.captnmoto...0_Schematic.pdf[/url] Cheers Geoff [/quote] Nice one, thanks Geoff! Interesting to see its got a paraphase splitter, Ive never seen one of those in a modern amp.

[quote name='RandomBass' timestamp='1374578574' post='2150316'] I've just checked my LB30 schematic and the volume control is post effects, in fact it is right before the power stage. Cheers Geoff [/quote] hey Geoff, are the schematics available online?

Fraid not, Ive been stalled doing other things. Life getting in the way and all that A good friend has suggested I prototype the preamp with a smaller power amp and power supply, to iron out the bugs. Im tempted to take his advice.

We've been forgetting our very own Jim Fleeting over in Harrogate: [url="http://jimfleetingguitars.com/"]http://jimfleetingguitars.com/[/url]

Are the depth and drive knobs actually rotary switches? Billy, did I play your rig at a bass bash the other year?

[quote name='charic' timestamp='1373531575' post='2138589'] How about £0.11 a watt [url="http://basschat.co.uk/topic/211499-1600w-quantum-matrix-poweramp-l175/"]http://basschat.co.u...-poweramp-l175/[/url] [/quote] If we dont want all off the watts, are you willing to split? (Someone was bound to make that joke!)

Ive been burned - £26 per watt for my rig! But these are big round Barefaced Ashdown valvey watts, as my neighbours will confirm

[quote name='bluejay' timestamp='1373190359' post='2134431'] Bump because this is a brilliant thread, and here is a photo of Happy Jack with his new Matamp, taken at the Junkyard Dogs' gig last night. The amp (as well as the bass and cabs!) sounded awesome [/quote] OMGOMGOMG - a Matamp on top of two Barefaced! Thats got to be absolute heaven! Jack must be Happy indeed! For the top end, you might be able to give the Matamp lads a call and get them to change the tone caps and / or alter the gain of the input stage. They should be able to make you the exact amp youre after. If you do, bring hobnobs.

Valve amps have switchable impedance. If, for example, you are used to plugging two 16 ohm cabs into the amp, then the amp should be set for 8 ohms. If you only plug the one cab in, then you should switch the impedance selector to 16 ohms.

My brother is a pro keys player and uses a Triton, and still uses it after nearly a decade. The downside is that they are still incredibly expensive, compared to what you might get from Roland or Yammy.

I was playing around with a design this morning, its actually going to be a hybrid design, with valve input stage, solid state EQ, and a valve overdrive section (the second valve section from the Bassman, with the directly coupled cathode follower). I was unsure about whether the EQ should precede or follow the overdrive section, but Ive figured out a way to make it work how I want. The bass frequencies bypass the overdrive section, so you always get the low frequency thundering presence. The bass control just controls the gain on this path (+15dB, to - infinity). The treble control, when set to boost (up to 15db), boosts pre-overdrive to really drive the valve hard. When you wind it down to cut (down to - infinity), it cuts post-overdrive, so you can cut out all the fizziness if needed. Its a modified Baxandall, with one half of the pot forming part of a potential divider controling the gain directly, and the other half a part of a potential divider controling the negative feedback. I still need to prototype it on breadboard to make sure it'll work, but you can do things with opamps that wouldnt be practical with valves. EDIT: Heres the gain curve for the bass and treble pots, +15dB to -inifity:

Of course, the other option is to take a balanced out from the solid state preamp. This would also simplify the build, as the global negative feedback components would be mounted to veroboard instead of tagboard.

I need to check my values, but Im pretty sure theres tons of headroom on the concertina so the output valves will be driven way into class AB2 by the time the concertina starts to clip. And at that point, its going to be LOUD! If the load of the concertina is perfectly resistive, or close enough, then you get better balancing than you would with a long tailed pair. Adding another trim pot into the design is just something else to forget to tweek when youre servicing the amp over time, and is something I dont want to have to worry about - I would much rather it was well balanced by design. Yeah, Im starting to have doubts about the power supply. However, John gave me the design, its pretty much the bass amp he's been building for clients for years, and Im willing to bow to his experience here.

Hey Umph, will post it when Ive got it to hand. The power amp is based losely on the bastard child of a Marshall Major (concertina phase splitter driving a long tailed pair) and a Hiwatt 405 (cathode followers driving the grids of the output valves). I'll add individual biasing for each output valve on the advice of John. Ive recalculated the values using the curves from the Chelmer Valve ECC81/2/3 datasheet, and pretty much followed the recommended operation from the 6550 datasheet for class AB1. If you look at the schematic for the Hiwatt STA preamp, its not so far to change the cathode follower of the ECC83 into a concertina, by splitting the load resistance (100k in the schematic below) between the cathode and anode. If you do this, then, since the ECC81 has such a high input impedance, each grid will see perfectly equal but opposite polarity siginal, therefore you dont need to use different load impedances (33k and 39k in the schematic below) on the anodes. Regarding the layout, yes it was a compromise. I had a choice between orienting either the PT or the chokes at 90 degress to the OT, the only way to have all three orthoganal would be to use a lay down type power transformer and that would have come with its own difficulties. From what Ive read, chokes tend to be noisier than transformers, so they were the critical component to be 90 degrees to the OT. Im not concerned, since the Hiwatts, as well as the big Orange and Matamp chasisse that Ive seen picture of have had their PT and OTs in the same orientation.

[quote name='umph' timestamp='1368987165' post='2083731'] Looks good, just wondering why you went for a choke on both the power supplys? Resistors would've been fine and saved a lot of space. [/quote] There would be quite a bit of current flowing through those resistors, so I wouldnt be happy with the dessipation or the voltage drop. Next one I build probably wont have dual chokes, but this is an experiment in overengineering.

Ive 5 at the last count - a couple of basses that just wouldnt be worth selling, another one thats still broken after 15 years and still not been fixed, and one Ive lent to Mert. And then Ive got The One, my blue P bass I built at Jon Shukers gaff. Its not perfect, but its mine. And soon to have some home wound pickups too.