DHA

comments welcome [url="http://cgi.ebay.co.uk/DHA-VT1-DI-Bass-Drive-valve-O-D-distortion-DI-pedal-/310244231271?pt=UK_Guitar_Accessories"]http://cgi.ebay.co.uk/DHA-VT1-DI-Bass-Driv...tar_Accessories[/url]

[quote name='BigBeatNut' post='933344' date='Aug 23 2010, 09:05 AM']I've seen a 3 knob DHA VT1 Purist Bass for sale. The middle knob is "colour". My best guess is that this is a tone control. Can someone confirm and/or explain in more detail ? Thanks, Andy[/quote] it's negitive feedback. This normally has three settings via a centre off switch, one via a resistor so is little like "presence" on amps, another setting is via clipping diodes so is a fuzz type distortion, the centre position is colour off. Both settings reduce the level but add distortion and compression.

[quote name='Tdw' post='931238' date='Aug 20 2010, 06:53 PM']Hi , i have a trace elliot gp7sm ah300 head that destroys amp fuses very regularly. They never blow when the amp is switched on and working but rather when powering up or down (while the mute switch is off ) its hard for me to say if its on power up or power down or both. I have tried various fuses in the plug and it doesnt seem to make any difference. Just to clarify the amp fuses are 3.15 amp 250 volt glass fuses, the ones im using are fast blow. Sometimes it may go a week or more before blowing a fuse, at other times two may blow consecutively. Also the mute switch is somewhat crackely when pressed although i dont know if this has any relation to the fuses blowing. Any suggestions on what might be causing this and what could be done about it?[/quote] The fuse in the mains plug is there only to protect the mains cable. Is it a kettle plug type? if so try another fitted with a 5A fuse. If the mains cable is 5 or 13A then you can just fit a 5A in the existing plug. It's a common issue with all amps as there is a large inrush current at switch on which is way above the normal operating current.

[quote name='Musky' post='922261' date='Aug 12 2010, 07:25 AM']Sounds like you might have a seized voice coil. The other possibility is that something has got itself stuck between the cone and the frame.[/quote] +1

[quote name='fdavidso' post='921627' date='Aug 11 2010, 02:12 PM']Ok, thanks guys, I know that I could buy another box that does something different. That's no the point - how do I solve the problem as stated? Does anyone have any thoughts?[/quote] not sure there is a way to do want you want with a lot of custom electronics.

[quote name='Bo Millward' post='918961' date='Aug 8 2010, 07:14 PM']Any suggestions on what kind of tone caps are best for bass? Which would give me the most clarity and high frequency out-put? Cheers Bo[/quote] Metallised Polyester or Polypropylene, as for value it depends on the circuit design.

[quote name='fatback' post='911544' date='Jul 31 2010, 11:12 PM']What's the lightest power supply that'll work with a VT-1? Anything I can source on Amazon or ebay? The one I'm using is the size of a brick and weighs more than my amp (really). I don't know if it's standard or not, as I got it second hand. Thanks for your help[/quote] maplin - L49BR or smaller still and works anywhere in the World - Rapid - 85-2936

[quote name='cycrowave' post='903638' date='Jul 23 2010, 10:44 PM']hiya im the proud owner of a westone thunder 2 with an xlr out on it. im a little confused by the xlr though..... im guessing it has a balanced out, so im unsure what type of lead i should be using with it and i'v had varying responses from different sources. everything was great until the first time i gigged it using an unbalanced lead. got a really nasty hum through the house bass amp. i borrowed the soundmans balanced xlr to jack lead and didnt get any sound at all so had to just soldier on and cut all the mids and highs from my tone to kill the hum. any advice on the correct type of lead greatly appreciated, thanks for your time lewis[/quote] I don't think it is balanced from what you have said. If it is there will be circuit board inside or maybe a transformer. If a circuit board it will need power. dave

[quote name='ollie.v' post='896968' date='Jul 16 2010, 11:12 PM']hi ,im new to this page and am after some valued expert advice. i have had bassman 135 for about 15yrs. its been reconditioned several times ie,transformers diodes etc on numerous occasions ,as with all classic gear,its temperamental. but the real problem i have is trying to match the right valves with it for that original sixty's valve sound. when you purchase a quartet or (corner) of valves,they are all different and give the amp a different sound each time. do you have any recomendations please?[/quote] what a great amp you have! yes, different valve types will have an effect on tone. i would suggest some nice NOS RCA's or Mullards will sound great and just like the original intended sound

[quote name='willyf87' post='896745' date='Jul 16 2010, 06:09 PM']Hi Dave, Really interested in this item at the moment, just want to know whether it is capable of handling my effects rig which consists of 2 types of fuzz a boss od, chorus and flanger, if it was to be connected directly through this box to a pa mixer? Cheers[/quote] Yes, it's designed to work with instruments and line level effects and to be used to drive desks, amps and PAs

This new pedal was a custom job but once it was complete it looked like a useful addition to the range. [url="http://cgi.ebay.co.uk/DHA-DI-EQ-Boost-balanced-DI-3-band-EQ-Q-boost-/310232973440?cmd=ViewItem&pt=UK_Guitar_Accessories&hash=item483b538080"]http://cgi.ebay.co.uk/DHA-DI-EQ-Boost-bala...=item483b538080[/url] Free P&P to UK based BC members if ordered direct, i.e. not ebay. regards Dave

[quote name='Stinkfoot' post='890467' date='Jul 9 2010, 02:46 PM']hi, recently got the DHA VT1-purist but dont know what its amp rating is i know its 12v & it is working with only 300mA,but would like to know what it should be running at..? Question 2, (unrelated) i have a mixer amp but at the moment only the one speaker but it has two input jack sockets that can be used for either in or out (either one), can i connect left & right speaker out from mixer into the one speaker..?[/quote] VT1 requires about 150mA but draws a lot more at switch on as the valve warms up. 300mA supply will be fine Question 2, (unrelated) i have a mixer amp but at the moment only the one speaker but it has two input jack sockets that can be used for either in or out (either one), can i connect left & right speaker out from mixer into the one speaker..? NO result if you do will most likely be a dead mixer. the jacks on the speaker are for extra cabs not plugging in another amp.

[quote name='sk8' post='889678' date='Jul 8 2010, 04:53 PM']Thanks for the reply Power supply still needs to be centre -ve though, yeah? Bit confused with the positive ground bit[/quote] Yes, centre negative. The PNP transistors use a negative supply so the ground or 0V is more positive than the rail.

[quote name='sk8' post='888976' date='Jul 7 2010, 09:37 PM']Whenever i plug it into the daisy chain my power supply switches off. Checked everything and thats fine. Can run it off a separate 9v supply and it works a treat but as soon as i daisy chain it with the rest of my pedals they all go off. Not had this before. is it something obvious i've missed? Checked polarities, etc.[/quote] It uses PNP Ge tramsistors so requires a positive ground. So when you plug in a daisy chain power supply with negative ground it is shorted out. Needs a seperate power supply.

[quote name='TDL' post='878381' date='Jun 26 2010, 07:56 PM']Sorry guys, didn't see your replies. Thanks for the advice. I have now tried things out but I'm a little bit hesitant. I'm using this set up: bass --> Markbass Distorsore pedal --> Ampeg SVP Pro --> FX return of Markbass SA450 I haven't tried it yet but I might also want to use my GT-6B somewhere in the chain. What I'm worried about is when I tried this last night for about an hour there was a kind of burnt plastic smell. It might just be the Markbass pedal as it's new, however in the Markbass SA450 manual it said maximum voltage for the FX return is 12Vpp. I don't really know what this means but as there's a lot of gain on the distortion pedal followed by loads of gain on the Ampeg preamp (I also don't understand why the Ampeg pre also has a gain and a master volume when it's a preamp, I thought it should only have gain?) I just didn't want to overload the FX return and fry anything. Also, the Markbass FX loop is in parallel so both preamps EQ work at the same time - this actually sounds great but again, I don't want any damage. I'm probably just being stupid but it doesn't hurt to ask. Thanks[/quote] 12VPP (peak-peak) is a lot. The pedal that drives the FX is most likey is powered by a 9v battery or a 9V power supply?, if so the most it could put out will be 9VPP and that would be flat out.

[quote name='Bassulike66' post='876196' date='Jun 24 2010, 10:16 AM']I'll keep this as breif as possible..... Hartke 3500 amp, 4.5XL cab, 115XL cab, all at 8 ohms. Anyway, last night i was only running through the 4.5 cab, volume level 2... I was trying out an OBD 3 pedal, connected via a Korg tuner, dbx parametric equaliser and TC comp/gate (all rack mount). When i pressed the pedal i had a serious amount of hiss..ok, i half expected this! Tried to adjust the TC unit to cut down on the hiss....No such luck! Dissconected all other units and connected bass directly to amp. Checked all leads, and batts in bass....still got the hissing and quite a severe loss of power! I have turned the amp upto 9 and it doesn't even rattle the windows...lol. Tried the amp solely through the 115 cab and it acts exactly the same. So, im thinking amp and not cabs dead... Cant really hook it up and cross reference it with anything else until next Monday's rehearsal.. Also had a quick look inside the amp, could'nt see any obvious schorch marks or blown components,...valve also looked intact. Didn't have time to check for dry joints. Any pointers would be greatly appreciated.......[/quote] impossible to debug these things by email, but I was the tech looking at this I would check out the amps pre-amp stage first as it may have been damaged be a duff pedal. Is there an FX loop? If so then try plugging into the return and see if there is still hiss and low level, this would mean a power stage issue if still duff or pre-amp if working.

[quote name='The Burpster' post='862674' date='Jun 9 2010, 10:04 PM']Dave, it did take a while to come but the VT-1 is very very good. Its a lot more clever and versatile than I gave it credit for or expected. I have now with about an hour of fiddling got exactly the tone I was looking for.... So thank you for a great piece of kit. One thing, while I appreciate why it was designed the way it is, it would be really cool if you could use the line in to play MP3 (or in my case drum machine) whilst in an effects loop as opposed to 'just' through the headphone side of the system. Just my thoughts.[/quote] Many thanks for the kind words. The headphone amp and the line in are solid state and therefore not in the signal path as they effect the tone. To add an FX loop with blend is to much in the pedal format as I only use active FX loops and use a valve, so that would be 3 on the VT2 and 2 on the VT1. I have added a valve driven blended FX loop on the VT3-Twin-EQ in 1U rack format.

[quote name='victor5string' post='864114' date='Jun 11 2010, 10:29 AM']Just got one of these pedals of a very nice chap on this forum, and i just love it the pedal is never turned off it works so well for what i do(rock/metal). but and i know this may seem a silly question but what does Float and Ploat do on the DI swithc in know ground lift will emove hum but the others i have no idea. also when using the pedal as a pre-amp for recording can i use the headphone soceket at the same time to get my own siganl to some headphones or would this cut the singnal to the desk? cheers Vic[/quote] hi Vic, The DI ground lift has 3 positions, ground, float and ploat. Ground means the pin 1 of the XLR connector is connected to ground, Float means it's totally disconnected and Ploat means it's connected to ground via a 10R resistor and a 0.1uF cap. Its there to remove ground loop problems should there be any. Yes you can use the headphone socket at the same time. Dave

[quote name='steve la teeth' post='848062' date='May 25 2010, 11:29 PM']Hi Dave Are you still looking for a bass player? Steve[/quote] We are chatting to Chris at the moment and arranging at jam. If that does not work out then will let you know. Thanks Dave

[quote name='edster' post='845966' date='May 23 2010, 08:05 PM']I have an American market GK 700RB-II. I use a step down transformer to run it and was wondering if it's possible to have some sort of conversion done so it can run from the UK mains. If it's possible, is it expensive and perhaps more trouble than its worth? Thanks in advance.[/quote] Depends on if there is a 240V mains tap on the mains transformer, if there is then very simple, if not then you need a new transformer.

[quote name='Skezza' post='845775' date='May 23 2010, 02:34 PM']My son has bought a secondhand superfly head 500watts, As yet he has no speaker cabs and we are looking for a couple of 4 ohm cabs. In the meantime he wants to know if he is ok using my trave elliot 1518 8ohm cabinet on one side and nothing on the other or must both side have a speaker attached. cheers in anticipation for your help[/quote] depends on the wattage handling of the 1518 cab. Also check what is the min impedance of the Superfly, if it is 2ohm them two 4 ohm cabs will be fine, but if it is 4 ohm min then you will need two 8 ohm cabs.

[quote name='discreet' post='840754' date='May 18 2010, 12:37 PM']I have a 500W/240V solid state amp which for some reason intermittently blows the fuse in the mains plug, which is rated at 5A. It happens like this: the amp is working perfectly OK, and I switch the amp off. When I come to use the amp again, I find (occasionally) that there is no power, and the 5A plug fuse has blown. It doesn't come on then blow the fuse, so I'm guessing it must blow the fuse at power off... I replace the fuse, and off we go again. Would I be right in thinking that the plug fuse is generally to protect the mains cable, as the amp has its own internal 6.5A fuse (which has not blown)? Or is this just bullplop? And if this is the case, would replacing the 5A plug fuse with a 13A fuse solve the problem? Or is it a big dangerous no-no? Could there be something wrong with the amp? Am I being a complete spanner, or what? Thanks![/quote] you are right the mains fuse in the plug is to protect the mains cable. Try a bigger mains cable and fuse, don't just put a 13A fuse in a 5A cable.

[quote name='dead' post='841079' date='May 18 2010, 04:26 PM']everything seems to be ok now I'll just chage the valves. I'm about to built a footswitch for it, I've understand how to wire it but I would only like to know if and how I can power LED's for each fonctions ?[/quote] I have explained before that this is a custom footswitch for use with a midi controller, a one off built to order for the original customer. Won't work with my footswitches and theres no power for LEDs.

[quote name='mrtcat' post='841378' date='May 18 2010, 08:57 PM']Hi Dave, I've got an Ampeg SVT-6 Pro head which powers a mesa boogie cab. Now the sound is awesome and exactly what I wanted but one little thing is driving me nuts. I switch the head on and for about 10 - 15 seconds there's silence then a moderately loud click and the amp sends a constant buzz throught the cab. The buzz is loud enough that I can't mic the cab live which is my preferd technique. Is this likely to be something I'm causing or does the amp need to go back from whence it came? Ive tried different cables, power leads etc. Any advice would be most welcome. Cheers[/quote] could be something silly like a ground loop but does not sound right, might be worth getting it checked out.