DHA

[quote name='simwells' post='1352978' date='Aug 26 2011, 08:20 PM']I was sent it with it but the details on it are the following; Model No: MWD-1200800F Output is 12V 800mA. Chinese made and probably not up to the job?[/quote] It will be badly regulated hence the hum. This one 85-3113 from Rapid Electronics is recommended

[quote name='simwells' post='1352672' date='Aug 26 2011, 04:15 PM']I bought this pedal quite a long time ago from here but have never really used it because of one major issue. When engaged it hums a lot as I haven't heard this comment from any other users I presume this is likely to be an issue with the power supply that the previous owner supplied it with rather than the pedal itself right? Thanks[/quote] what power supply are you using?

I have at long last got the website up and running again! www.davehallamps.co.uk I am looking for some bass sound clips of my pedals and would be grateful if any DHA users could supply some. Full credit given and links to band sites etc. in return After clips for current range so - VT1-MK3-Bass, VT1-Bass-Drive (VT1-Std-Bass is the same thing), VT1-EQ-Bass-Drive, all the new VT2-Twins, VT1-Bass-Compressor, DHA-Di-EQ, VT3-Twin-EQ-Bass-RM, fuzzy feeling bass. If anyone wants to do a review, comment, etc. on any of my pedals then I will also be grateful and links to band web sites, etc. in return.

[quote name='Chris Horton' post='1133829' date='Feb 19 2011, 09:48 PM']I just looked on multi map and found that DHA are about a 90 minuite drive from my house ya learn something new every day . . . . . . . what a plomker [/quote] A village called Dolton, near Winkleigh. I don't keep much stock as I build to order. But, the Vt3-Twin-EQ-Bass-RM is really a VT2-Twin-EQ-Bass plus a VT1-Bob the blender with a tuner mute and 2 extra DI's. They sound like all my other Vt1 and Vt2 pedals, the tone is the same. Check out reviews on the VT2-Twin-EQ-Bass. normally have a Vt2 here so you are welcome to try that.

[quote name='fatback' post='1095559' date='Jan 19 2011, 07:57 PM']A little bump for this. [/quote] sorry, don't give this away. Took me months to perfect the design and I don't intend to let the competition know what I do.

[quote name='dan670844' post='1093551' date='Jan 18 2011, 10:03 AM']Arrgh I forgot about Torres! yes they does a 200 watt one I believe. But I really want is just a valve poweramp just a big KT88 monoblock monster that I can feed on a variety of preamps! that is rackable. With proper cooling etc and modern components. In the old days (before my time) they used to build slaves not anymore... Mesa and others have had a go but they didnt seem to take off that well. A lot of circuit Guitards seem to use the Marshall EL84/34 rack power amps these days I guess they get it![/quote] Torres is a good place to start. I designed their boxer range which I would suggest is a good place to start. The instructions are good and deal with the safely very well. A fender bassman (much used by guitarists) is really quite a simple amp and Torres have kits for these as well. With the right bass cab (4x10" in the Fender combo) it will sound great with bass. good luck and let us know how you get on.

[quote name='Thurbs' post='1073728' date='Dec 31 2010, 02:48 PM']Hi all. I have just bought this amp second hand off a fello Basschatter and have come across the following problem. All was well until I DI'd to the PA. As soon as I plug in there is a horrible hiss from the PA speakers. The volume of the hiss gets louder when you turn up the input dial. It makes no difference if anything else is plugged in to the amp, if any of the nobs or switches are at any setting. The only effect on the noise is the input dial. The hiss is only evident on the PA, the speakers are still silent. I have tried different PAs and DI cables so it is not either of them. After taking it out of the case, I cant see any bad connections or wires missplaced... Any ideas?[/quote] The hiss might be on the amp the whole time and it's just you can't hear it via the bass amp's speaker cab and it's just the PA speakers that can reproduce it. Or, the Di circuit is damaged or just not very good.

[quote name='binky_bass' post='1059703' date='Dec 15 2010, 04:30 PM']Got an Eden wt800, got a line6 pod pro, got a 4u rack, what's the best way of running them together in the rack to get the tone and power of the Eden with the effects of the line6? Cheers! Russ.[/quote] If the Eden has an effects loop then plug the line 6 in there. If not then there is only one way, bass into the line 6 and then onto the amp Dave

[quote name='BottomE' post='1058918' date='Dec 14 2010, 08:04 PM']Hi, I am starting to dread the soundman approaching with his DI plug in hand. I don't do many gigs with the amp DI but the last couple have been a nightmare. The tech said that the output from my DI was "too hot". What does that mean? So he ended up taking an out from the tuner! I also remember a guy in a studio struggling to get to grips with the DI on the amp. The amp is a Little Mark 2 and sounds great through the cabs that i use. So could there be a problem with the DI? If there is how can i find out without a costly visit to a tech? Many thanks.[/quote] I have seen this on some amps were the output is very high. I think some amps do this to drive a slave amp and are not really designed to run a desk. You could buy a DI pedal and run it from the tuner out and let the signal pass thou to run the tuner as well. Make a range myself dare I say? Dave

[quote name='BottomE' post='1058113' date='Dec 14 2010, 01:33 AM']Hi, on the back of the Little Mark 2 is a Speakon out and 1/4 inch out. If I want to get the amp running at 4 Ohms with 2 TC electronic cabs can this be achieved by connecting 1 Speakon cable to one cab and using the "link" output from that cab to the other speaker or should i connect one cab with the Speakon and the other cab with the a 1/4" jack? (connect them independently) Thanks[/quote] I think both ideas would work but I would check that the Speakon and the 1/4" are connected in parallel first and that pluging the 1/4" in does not disconnect the Speakon. Manual should tell you this. dave

[quote name='porterpr' post='1055199' date='Dec 11 2010, 05:56 PM']Thanks Dave ....can you suggest a good stereo power amp also what does class 1 class 2 etc mean?[/quote] Solid state power amps are not really my thing so would not know what to recommend, sorry. But, there are many on here which will be able to. Do you mean Class A, Class A/B? if so its to do with the design of the output stage. But, Class D (Digital) amps are very good now, they provide very high power in a small light weight package, also not to costly.

[quote name='porterpr' post='1054952' date='Dec 11 2010, 01:51 PM']Hi Dave I've got a Trace Elliott gp12 smx pre amp could you give me any advice on a power amp that would go with it as I'm not sure What to get (mono amps seem hard to come by) Thanks.[/quote] If you can't find a suitable mono amp then get a stereo that will bridge into mono. Dave

[quote name='rageingtelephone' post='1050753' date='Dec 7 2010, 05:21 PM']With the 4ohm cab [/quote] did you sort this out? interested to hear if and what the fault is? Dave

[quote name='obbm' post='1048076' date='Dec 5 2010, 11:16 AM']An 8-ohm cabinet with 4 identical speakers will either have 4 x 8-ohm speakers wired in series/parallel or 4 x 32-ohm speakers all wired in parallel. Without changing all the speakers for 16-ohm or 4-ohm or disconnecting 2 speakers there is no way you can rewire an 8-ohm cabinet to be 4-ohms. It's against the laws of physics.[/quote] I agree, but at the time I was thinking of a stereo cab like some of the Marshalls. These can be 2x10 at 8R a side which and be wired or even switched to 4 or 16R mono. So, if you look out for a stereo cab might be possible.

[quote name='Jazzjames' post='1047499' date='Dec 4 2010, 04:21 PM']Hello, I'm thinking of buying a 4x10 cab for use on loud function gigs, and a few in my price range have popped up, but they're all 8 ohm impedance. Is there a way of rewiring the cab to make it 4 ohms? Thanks, James[/quote] Could be but it depends on how the 4x10 is wired up now. Dave

I have had a few asking if I still do the lower cost unpainted VT1 pedals, I had stopped them as the writing does wear off the unpainted boxes. So, have made a "new" version -http://cgi.ebay.co.uk/DHA-VT1-Drive-valve-tube-overdrive-bass-guitar-/310270127603?pt=UK_Guitar_Accessories&hash=item483d8a6df3 can do them in a range of colours on request. Free UK power supply to any BC members that buy direct, i.e not via ebay. Dave

[quote name='obbm' post='1022476' date='Nov 13 2010, 02:36 PM']OK. What I should have said is that they don't have the level of voltage amplification you'd expect from a pre-amp.[/quote] sorry, was not having a go. Being an op-amp design you can run them up to 15VDC and this will give a 14V ish peak-peak, even with the 9V battery you can get 8V ish. I have found that this can drive most power amps, or am I missing something?

[quote name='obbm' post='1021169' date='Nov 12 2010, 11:21 AM']DI boxes are passive so not a lot of use in this situation. A small mixer like the Spirit Folio Notepad or a small Samson is all you actaully need. The mixer channel should be very clean and they all have headphone amps. All you need to do is plug-in your MP3 source and you're away. [url="http://cgi.ebay.co.uk/Spirit-Folio-6-Channel-audio-mixer-/120644256812?pt=UK_Mixers&hash=item1c16f5442c"]http://cgi.ebay.co.uk/Spirit-Folio-6-Chann...=item1c16f5442c[/url] [url="http://cgi.ebay.co.uk/Soundcraft-SPIRIT-FOLIO-Notepad-audio-mixer-/120644859270?pt=UK_Mixers&hash=item1c16fe7586"]http://cgi.ebay.co.uk/Soundcraft-SPIRIT-FO...=item1c16fe7586[/url] [url="http://cgi.ebay.co.uk/SPIRIT-FOLIO-NOTEPAD-MIXER-SOUNDCRAFT-/260690694310?pt=UK_Mixers&hash=item3cb26050a6"]http://cgi.ebay.co.uk/SPIRIT-FOLIO-NOTEPAD...=item3cb26050a6[/url][/quote] My DI's use an op-amp design so are active.

[quote name='rageingtelephone' post='1017018' date='Nov 8 2010, 11:05 PM']Thanks Dave, yeah I did change all six of the power valves not too long ago and used the bias controls on the back. I've also taken them all out to check and all seem fine (no cloudyness etc), and also all glow as normal when amp is turmed on. So i dont think the tubes are blown... could a dirty switch cause any of the trouble I mentioned before? I was aware of the dangers of not matching the impedance correctly, but as far as I knew I thought it was only if the impedance of the speaker was lower than the amp that damage could occur? Cheers, Thom. I should also mention, whilst playing another show the other day it started out fine and normal, then the same volume drop happened after a couple tunes. I was using the correct impedance cab this time.....![/quote] Did you set the bias with a 4 or 8ohm cab attached?

[quote name='dunnymod' post='1018662' date='Nov 10 2010, 12:26 PM']Hey there, just a quick query at this point – I use a DHA VT1 EQ bass almost exclusively, either through an amp or direct into the PA through the XLR. Within the last month whenever I play through the pedal there is now a background noise where there wasn’t before. Its not a Buzz or a Hum or an electrical noise, it sounds more like the pedal is constantly ‘breathing out’??? This is the same through the PA and the amp, and not there when I bypass the pedal. As this is my first prolonged experience with valve equipment im not sure if this is normal. Ive had the pedal over a year now, and this breathing sound has only developed, like I say, in the last month. Just from reading other posts about valves it seems that a pre-amp valve is quite hard to break, (electro harmonix fitted as standard) and the tone of the pedal has not changed, so my question is really is this normal once valves have been ‘broken in’???? Or could it be something else in the pedal?? Any info would be appreciated. cheers[/quote] Sounds like a power supply problem. Dave

[quote name='rageingtelephone' post='1017018' date='Nov 8 2010, 11:05 PM']Thanks Dave, yeah I did change all six of the power valves not too long ago and used the bias controls on the back. I've also taken them all out to check and all seem fine (no cloudyness etc), and also all glow as normal when amp is turmed on. So i dont think the tubes are blown... could a dirty switch cause any of the trouble I mentioned before? I was aware of the dangers of not matching the impedance correctly, but as far as I knew I thought it was only if the impedance of the speaker was lower than the amp that damage could occur? Cheers, Thom. I should also mention, whilst playing another show the other day it started out fine and normal, then the same volume drop happened after a couple tunes. I was using the correct impedance cab this time.....![/quote] The impedance does need to be match but damage is more likely if a lower impedance cab is used. The valves are expecting to see a load of a few 1000ohms depending on the type. The speakers are very low impedance so an output transformer is used to match the valves to the speakers. If half the impedance speakers are used then twice the current goes via the tube (but not for long!) so in your case only half the required current was drawn by the valves so I think it would not have sounded very good, thin and weak? The cloudyness would be if there was a leak and the glowing is just the heaters so not a good way to see if they are working. But saying that looks like it may be something else, so it's time for a techie. Dave

[quote name='gareth' post='1013847' date='Nov 5 2010, 11:06 PM']I have never quite understood that I had an SVT II Pro and there are controls on the back that allow you to self-bias - admittedly only in two groups of three a side. So are you saying that there are further ways of biasing the tubes that presuambly must be inside the amp and only known to techies?[/quote] All valve amps need to have matching output valves that will need biasing. If the SVT has controls to self bias then that's great but it must be done when valves are changed. Most amps have a pre-set inside the amp that allows the techie to set the bias.

[quote name='rageingtelephone' post='1012223' date='Nov 4 2010, 04:02 PM']I think my ampeg is early 90's? It says 'svt 2 pro' in all blue writing except the 'v' which is red. The serial number simply says 'D'. I normally play this amp through an Ampeg 6x10 4Ohm cab live, but at smaller shows and rehearsals I use an SWR goliath junior III rated at 8ohms unfortunately. I got advice from a tech guy and he say it should be fine to run through an 8Ohm cab instead of 4Ohms, and it does work albeit a strange distortion when bass guitar is turned to half volume. BUT a couple of nights ago half way through a number a huge volume drop occurred. I thought the amp had shutoff, so I turned it off and on again to no avail, only being able to get enough volume with the gain and master much higher than normal. I should mention, a few days before this happened, a loud static noise introduced itself, going up and down in volume randomly. Even with the input gain at zero and the mute switch on... the only thing that affects it is the master volume or putting the amp into standby. I have replaced all the power valves about four months ago. I read that it could be a loose/dirty pin in one of the valves so i took them all out, inspected them and wiggled them. The master volume pot is also dirty as loud pops happen if you dont twist the knob alot to clean before switching the amp on. Upon reassembling the amp, there seemed to be no change. Anyone got and ideas?! Help will be much appreciated!! Thanks.[/quote] Might not be the problem but very bad advice from your tech guy. With valve amps it is important to have the correct speaker impedance connected as this sets the reflected load on the power tubes via the output transformer. I think the power tubes might well be blown. When you changed the valves it should have been re-biased as well. sorry, Dave