Mikey R

[quote name='JapanAxe' timestamp='1367829523' post='2069776'] That's very tight! Maybe MDP will lend you his big triangular 'zero fret' file to create some more clearance? [/quote] Yeah, it was too tight for comfort, I bought a bigger punch and widened out those holes, theres plenty of room now. [quote name='VTypeV4' timestamp='1367855404' post='2070262'] Can't believe I've missed this till now..! Looks like a great project, Beavis on steriods eh!? Great project, keep the pix and info rolling! [/quote] Cheers dude, its going to be a bit of a slow project, Im feeling my way dead slowly and making sure Ive got it right. The big Sovtek 6550 output vavles have arrived in the post Bigger than an EL34 but a little smaller than a KT88, I was worried they wernt going to fit in the small space behind the transformers, but its ok theres loads of room. EDIT: Just took a quick shot to show the scale of these mahoosize components, thought I'd share it here too: Thats a 50 pence piece for scale

Rather than start a new topic, thought I'd post this in here. Ive been reading through some threads in Amps and Cabs, and there seems to be a trend. In the late 90s, I used to play with quite a loud rock rap band. We had a hard hitting drummer and the guitarist used a 4 x 12. Because of the hip hop influence, most of our songs were driven by the rhythm section so were kinda bass heavy. All of this, and I kept up with my old (new at the time) Trace Elliot GP7SM 150 watt combo. This had the slotted front port and the smaller (10 inch maybe?) driver, so was probably far less efficient than a modern Neo loaded cab. Since I wasnt using an extension speaker, this was probably putting out around 80 watts. So why, as bassplayers, are we feeling the need for a half kilowatt stack for the low end? Are we competing with guitarists with terrible scoopy tone? Do we just like the headroom?

cheeky git - I hope youre looking after the brown bass!

I decided to stop procrastinating and start on the metalwork for the chasis. First will be to build the power supply and verify that works, so I started cutting the holes for the transformers, chokes and the big caps. Marking out, the old school way using paper templates. I really should have drawn these out on sqaured paper to ensure I got everything square and in perfect alignment, but I got pretty damn close using a lower fidelity method: Last minute check to make sure everything fits: And with the bulk of the holes cut: I still need to deburr these holes and cut the holes for the bridge rectifiers and circuit boards mounted inside the chasis. Still, its a good start. Checking that the holes are in the right place for the capacitor mounting clips: And the inside of the chasis: Its a little tight, and theres not much space between the terminals and the chasis. I can either file out a little around the terminals, or fill the void with hot melt glue. I'll probably do a bit of both, I dont want sparking here.

[quote name='MiltyG565' timestamp='1366896454' post='2058708'] Nope, that's not potato bread! [/quote] But its still breakfast. [quote name='Jack Cahalane' timestamp='1366910339' post='2058988'] I live on the Isle of Man Okay no I don't. [/quote] Bits of England arent on the mainland...

[quote name='richardjmorgan' timestamp='1366734146' post='2056609'] As someone who plays guitar in a metal band that lost its bass player earlier in the year and, as such, has been doing a fair bit of playing with just two guitars, drums and vocals, it makes a BIG difference. Funnily enough, it's given us a much clearer idea of exactly how we want the bass to work within the band, part of which is for it to be a lot more prominent in our overall sound. [/quote] Since youre a bass player, why not reorchistrate your songs for one guitar and bass? Playing bass in the three piece is awesome fun, you get to fill out the rhythm line AS WELL AS playing the bassline. [quote name='simes' timestamp='1366742820' post='2056764'] But what is the best bass for metal, that is the eternal quest.......... [/quote] Easy answer - MINE. But any way, back on topic - potato pancake, you make it with last nights leftover mash and some grated onion, eat it with egg, bacon and beans. The correct way to make it is plate sized and put the other stuff on top. Propper breakfast.

All the best looking people wear glasses. Just tie them to your head, you can headbang all night.

Just compare the guitar tone from Metallicas "Justice for All..." album with the black album three years later. Sure, they spent alot more on the studio, they layered more, and Bob Rock brought alot to the sound, but fundamentally that huge sound is from the guitar being supported from below by the bass played in unison. On Justice, the guitars are boomy and undefined, because James Het was boosting his own low end trying to get that huge sound without a bass player.

Cheers guys, I reckon its going to be the ones from Bluebell. I need to nail down the circuit first though, and I really seem to be procrastinating over that.

[quote name='Mr. Foxen' timestamp='1366292150' post='2050602'] Gas soldering iron exhaust is what I generally used. I've got a fitting for one of my gas irons for the purpose too. [/quote] Cheers Oli! Any suggetions on where to get turrets?

Cheers for the suggestions gents. Yep, hot air gun is the orthodox way to shrink your tubes (!) but I didnt have one handy, I dont think the hair dryer would be hot enough. But I didnt think of using a soldering iron - good suggestion bartelby! So ignoring the heat shrink for the moment (which might not even be necessary) I had a play with how the wiring would look on the actual bases: This single strand wire holds its shape niecely, I dont think the PTFE stuff will be quite so well behaved.

This project is really an exercise in totally overbuilding everything. The heater wiring for the power valves will carry just shy of 10A, so everything needs to be able to handle that. This is a trial run of the heater wiring. (The single strand wire will be replaced in the final implementation with PTFE coated multi strand.) Ive tried using some super chunky heat shrink to keep the wires together, however whilst shirnking it down, I melted both the wire and the cigarette lighter. Rethink needed!

[quote name='Dad3353' timestamp='1366273020' post='2050278'] Nice thought, but a bit late now, anyway, if it's not the case..! [/quote] Dont worry, the power transformer is specced so that I can use 6550s or KT88s, I could probably also use KT90s or KT120s. Unfortunately, with six power valves, tube rolling will be rather expensive! Next question, probably for Mr. Foxen and umph - Im thinking of staking my own turret boards. Ive got some phenolic board on order, does anyone know a cheap place to get turrets from? Ampmaker does screwmount ones: http://www.ampmaker.com/store/Screwmount-turrets.html Bluebell is probably the cheapest for classic turrets, when bought in bulk: http://www.bluebellaudio.com/connectorsturret.htm Any others?

Cheers dude! KT120s are a little weird, theres no typical operation on the data sheets so you have to work it out yourself from the graphs. I believe the new big Matamps are driven by KT120s so you definately can get a great tone from them. Personally, I decided to go with the tried and tested 6550 configuration from the data sheet, I just found it easier. Whatever you go for, good luck!

OP updated with the specs

The big caps and valve bases have arrived, so Ive been figuring out the best layout. Any opinions here would be greatfully received, its a bit of a squeeze. Unusual. This one maximises the space between the power valves and the big caps, whilst keeping the power supply components to one end. Plenty of space for the tag boards also: Classic. This ones a bit like a Hiwatt, with the caps in a line. Im not so keen on this one, as the caps are rather close to the power valves without leaving much space for a heat shield. Also, the wiring for the power supply will need to go right accross the width of the chasis, which will be both untidy and possibly a cause for hum: Or probably my favourite. This one should leave just enough space for the tagboards, but not much space if I want to add anything later. Theres plenty of space for a short heat shield. Also, the power supply is fairly well kept in one place, but the 600V HT supply will be right next to the center tap of the output transformer, which is really handy, and the first valve of the pre-amp is as far from the mains transformer as possible: There are compromises in all of the possible layouts, but thats always the case.

Im going to be running 6 x 6550 at 600v on the plates and 300v on the screens, theres no way I could drop 300 volts at those currents accross a resistor so Ive gone for the (fairly usual) stacked 2 x 300v HT supply.

Theres going to be two HT supplies, stacked one on top of the other, so theres one choke for each. Youre right about the big ones - output on the left and power on the right. This is the provisional layout, I'll know for sure if everything else is going to fit when the caps and valve bases arrive.

The iron has arrived!

How does a 2x10 compare with a 4x10 on axis? Is it just more sensitivity and power handling?

That body is amazing! I would be worried that a figured maple board may be too much bling, just my opinion though and happy to be proven wrong!

Can we get a gut shot? These are 2 x EL34, right?

Wow! Just, wow! Awesome work - looks incredible!

I might get shot for suggesting this - but has anyone been able to A/B the new GT200 against a modern Orange AD200? Similar beasts or totally diverged?