DHA

[quote name='tredders' post='15297' date='Jun 10 2007, 10:09 PM']Timface Any news on the sound clips mate? Cheers Mark.[/quote] I have them! Tim plays bass in our band so has to use a DHA pedal or he's out, only joking. We did them today and I will post them on the website in a few days. Tim has a VT2-Dual-Custom-Bass-RM so it covers just about all of the tones available in the pedal and rack range. Dave

Thanks for all the feedback guys, it's very useful so please keep it coming. I will put together a 2U super bass pre-amp as a starter and see what you guys think of it. Dave

[quote name='MoJ' post='15043' date='Jun 10 2007, 01:38 PM']Dave, I know you mentioned earlyier that you may possibley do a couple of units, but would it be worth doing a 'core' unit of say just the 2 independant channels, and then a list of optional extras that could be added like the compressor or blender? Obviously you couldnt have too many options as it would get silly and you only have so many hours in the day you can dedicate to your work. Not sure if that helps or is possible? Andy[/quote] Good idea.

[quote name='dood' post='15027' date='Jun 10 2007, 01:06 PM']I know there's a minority of stereo users out there, but if there was always one thing that made my choice of preamp even harder, was trying to find one with a stereo FX loop with a DI out (post loop) for each channel. The Warwick Quadruplet has one, as does the EBS classic, I think. but none others come to mind at the moment. I suspect not many people will want it or need it to warrant the cost addition.. but it'd be nice! (I have actually half decided to start building a preamp myself, including all the things I like - I have the rack case and most of the components too - but I'm lazy.. and it has always just been 'half' a thought! lol lol)[/quote] Hi, As all my stuff is handbuilt it's really not a problem to pick and mix the bits people want, so if there is a request for a stereo FX loop and stereo DI then you got it. I use a stereo FX return and stereo output stage on my own amp. Once you have tried stereo chorus and stereo echo there is no going back. Dave

[quote name='MoJ' post='14973' date='Jun 10 2007, 10:47 AM']Well, its not [i]that[/i] much when you consider that the only two Ampeg preamps being made at the moment are coming in at around that price. Add in to the equation that you're giving both channels tone controls (independant of each other I assume?) which Ive only seen on say the Ampeg BSP, and you maybe adding a compressor in there too, plus a footswitch to control all this (which I dont think are included wiht the Ampeg's but could be wrong) and its about right. Would taking out the silicon and germanium diodes and associated controls, and the colour controls do much to the price? I know I for one don't use those on my VT2, but cant speak for anyone else. Out of interest, where are you considering putting the compressor in the chain? As for the DI impedance, just looking in my trusty TE manual, which just so so happens to be near my PC, the spec at he back states the impedance as 600 ohms or greater. Wouldnt know if thats standard though. Not sure if DI out is overly essential, but if you did fit it Id make it post EQ if there is the option. Thanks Andy[/quote] Hi Andy, There will be a separate passive EQ on each channel. I may consider a different version with active EQ but I want to do this one first so that the signal path is pure and without solid state. I was going to leave the clipping and colour controls on each channel as they are not big cost drivers. Dave

[quote name='Stewart' post='14977' date='Jun 10 2007, 11:02 AM']Hi Dave, It should be capable of feeding 600 ohm at 0dB. There's a nice transformerless circuit here (figure 3): [url="http://sound.westhost.com/project87.htm"]http://sound.westhost.com/project87.htm[/url] Cheers, Stewart[/quote] Very useful, thanks Stewart. That's the balanced DI out sorted then! Dave

[quote name='MoJ' post='14950' date='Jun 10 2007, 09:56 AM']WOOOOOO!!!!! +1 for that! And +1 for a DI out too. I would say maybe not a crossover, but how about stereo/dual outputs, to at least allow a crossover to be used, or to bypass the 'high' part of the crossover for a full range and low pass arrangement. It would allow for a very flexible set up whatever though. I definitley like the idea of each channel having its own output so that levels could be matched. How about a blend control (not just the fx loop blender) to allow blending of the clean and overdrive channels? Would definitley like that option. How much roughly would soemthing like this go for Dave? Thanks Andy[/quote] Hi Andy, I think just a splitter and extra op-amp should give a line-level DI. Does anyone know what the impedance and level of a DI out is? Blending one channel with the other is interesting LED VU meter is in. Looking at crossovers. Stereo output could be an option and might even cover the DI issue as well. Cost would depend a bit on what we end up with and it may even be two or three models. But aiming to keep it around £500-£600. I know it's a lot but this will take about 2 weeks to make and have well over £250 in parts. Dave

[quote name='Crazykiwi' post='14187' date='Jun 8 2007, 01:47 PM']Dave how will we set the levels of either channel so that loudness isn't affected when we change channel? Would it be worth putting in a crossover as well?[/quote] Hi, Each channel is a separate circuit with it's own boost and output level controls so that the level of each channel can be matched regardless of gain settings. There will be a master output level as well. Being a simple guitarist I am not up to speed on crossovers, got anymore info? Dave

Hi all, I am building a new 2U rack pre-amp for bass and I would grateful of a bit of market research before the design is set in stone. It will have two separate channels, channel 1 will be a VT1-MK3-Bass but with tone controls, channel 2 will be a VT2-Dual-Custom-Bass but set to 1+2. Switching will be 1 or 2 and by-pass giving two separate channels 1 being low to mid gain and 2 being low to very high gain. It will also have a valve driven FX loop with blend (this is my "Bob the Blender") which will be switchable pre and post the overdrive channels. There will be a tuner output and footswitch mute. All the switching functions will be controlled with a footswitch as well as front panel overrides. We are talking 5 or 6 valves here. The plan would be to add my valve compressor design in as well once I am happy with the design. The Guitar version will have a valve Tremolo instead of the compressor. So, would it be good to know if this is a useful set up and should I have 2 valve FX loops one pre and one post? What have I missed, what's nice to have and what's must have? Would an LED level meter be good? thanks in advance for your help Dave

[quote name='presoulnation' post='9924' date='May 31 2007, 03:03 PM']Surely there is a lot of money to be made from hand built amps? Luthiers are fighting for custom in a saturated market all the time, but no bugger builds amps [/quote] Don't bet on it! I tried for years to get my amps off the ground without any real success. A handbuild valve amp takes many hours to build and when it's done you then have to tune the components to make it sound right which can take longer than the build. The way the big boys get around this tuning is to design a circuit that is working well within it's limits and hence not at it's best, a bit like a rally car and the production model version! Then theres the cost of the parts, cheap ones might work for a while but will effect tone. Maybe it's just a UK thing as in the US there is a good handbuilt amp market but over here very few want to pay the real value. Most of the amps I have built have gone to mates or pros that know what they want. I would add a note of warning about building valve amps, the voltages involved will kill so there are not many second chances Also if anyone builds and sell such an item you will have to CE mark it, if anyone is hurt or killed when not doing something silly then the builder will be to blame and we are not talking just a fine here. You will need a good range of test equipment to do the job correctly. I think building an amp for yourself is a great idea but building for profit, well that's another thing. Dave

[quote name='steve' post='8574' date='May 29 2007, 01:10 PM']Hi Dave, what are the differences between a valve guitar head and valve bass head? I've often wondered whether they're interchangeable[/quote] Hi Steve, A lot of the early valve heads were the same design for bass and guitar. The first Marshall Plexi's were in fact a copy of the Fender Bassman and the only difference between a Marshall super lead and a Bass was one 500pF cap on the SL. But, the new high gain amps for guitar lose all the bottom end required for bass. The design in layout is very much the same but it's the decoupling caps that change in value and some reduction in gain is also needed in the bass versions so that motorboating does not occur. So to answer your question yes they are interchangeable but a guitar will sound better on a bass amp but not so good the other way round. Dave

[quote name='steve' post='8489' date='May 29 2007, 10:12 AM']the link is [url="http://www.torresamps.com/index.htm"]here[/url], I've been looking at this site a lot myself lately. I want to build backup for my pignose to the same spec but I've other jobs pending[/quote] Hi, I work with Barry at Torres UK and can recommend their kits, in fact the Super Boxers are my design. They are guitar amps but I would be happy to help Torres with the re-design required for bass. Dave

[quote name='MoJ' post='8005' date='May 28 2007, 11:28 AM']Ah,so you cant escape the mighty Mullard then? Well,I asked Dave to fit some cryo's in mine,after some things I read on Bassworld posts regarding his 'Ice' range,and also what Watford Valves desribe them as too. Initially I didnt see what all the fuss was about and was also excited to get experimenting too.As it happens I swapped the EH cryo's back in and am loving it. Very bright indeed so not sure(bearing in mind your valve comparison sticky - something I based my choices on and found pretty accurate)that they'd be your thing.I do like a transparent and 'grindy' kind of tone. When I can afford some I still want to try some Mullards just to see what they're like.Natural curiosity n all! Did see some on Ebay kinda cheap but still dont have the money.May try a Groove Tubes remake or something. [b]Brycebites[/b],how do you find the NOS GE? Andy[/quote] Hi, I first tried Cryo valves after speaking to Watford Valves about the new Mullard remakes from GT and others. The remakes are made in China and are very poor and really nothing like the NOS. Beware there are many ebay sellers selling these as original Mullards. I asked Watford valves what was the nearist new valve to an NOS Mullard, the answer was cryo. After I stopped laughing Derrick told me he did the same until he tried them, so he sent me some. I think they are very good and not unlike the old Mullard ECC83 I use in my own VT1-Purist. BTW, cryo it not new as Mullard did it in the 60's, in fact Chris you may be using cryo valves already! Dave

[quote name='MoJ' post='7981' date='May 28 2007, 10:34 AM']Right,well after palying with valves again last night,the settings Ive got it on now are based on having the cryo valves back in(just something Dave said that got me thinking). The only switches I have on are the Fat switch(not sure its doing much and Dave said it works better on guitar but its called Fat,why wouldnt you want in on??)and the treble switch,which just pulls my original tone through the overdrive.The extra 'fuzz' that creates I just EQ out on my head.I dont turn this thing off now! I/p pad incindently is set all the way on.Gain 1 is around 1:30,and this varies up to about 2/2:30 depending on how much grit I want.Anywhere around there allows me to get a really nice transparent 'grit'. Gain 2 isnt too dissimalr to yours and thats around half 4.Dave's labeled mine 1>2,and thats about 10 o'clock.Its about as much OD as I can get really before that grinding edge of my tone gets lost.Not that anything above that doesnt sound good,I just dont think I need anything more. All thats then matched to my 'clean' level when bypassed. I have to say,if you like what I can only describe as a glassy tone,then try the cryo's [b]umcoo[/b].Especially if you like the standard EH valves Dave's put in yours.I say its galssy,because its like my normal clean tone and very transparent,but with a bit of extra shine too it. Ill see if I can try out your settings if I have time before my gig tonight. Thanks [b]umcoo[/b]. Oh,and thanks [b]Finnbass[/b] for your comments Andy[/quote] Hi all, I am glad you guys are all talking to each other about your settings and I find it very useful too. On the 2>1 or 1>2 thing - I changed the signal path on the latest pedals so that channel 1 is always first in the chain and drives channel 2 when in 1+2 mode. It used to be channel 2 drove channel 1. You will still be able to get the same tones but your settings may be not the same. The treble boost or bright switch adds a 500pF cap across the level pot this is an old Fender trick on their amps. It only has an effect when the level is not on full and removes the muddy tone on lower level settings. Many guitar players add mod this to their guitar's volume control for the same reason. The fat switch adds a tad more gain and increases the bass response, if your bass EQ is set high then you won't hear it so well. It's great on guitar. BTW, get your band's guitar players to try them as the bass versions work great for guitar as well. Dave

[quote name='acidbass' post='1982' date='May 19 2007, 01:27 AM'][url="http://members.aol.com/davehallamps/"]What a Website![/url] But on a serious note - [url="http://stores.ebay.co.uk/Dave-Hall-Amplifiers-and-Effects"]Linkage[/url][/quote] Hi, That's an old website which I must kill off! New one is www.davehallamps.co.uk thanks DHA