DHA

[quote name='The Funk' post='96006' date='Nov 29 2007, 10:25 AM']Hi Dave I've been a user of your VT2 Dual Bass for almost a year now. Great pedal and couldn't be happier with it. I'm now trying to convince my guitarist to ditch his distortion pedal for a DHA one. What would be awesome would be a pedal containing two preamp valves in a similar configuration to the VT2 Dual with a power amp valve on a dummy load, as in the VT5 Valve Hybrid head. Do you think this would be possible and could you give an indication of potential size and cost? Thanks Syed[/quote] A VT5-Bass is really this already, just has the compressor and FX loop as well but no SS power amp. I am making one of those at the moment for a BC member. It would be a big pedal with 2 large transformers and not really useable. A better solution might be a 2U or a small head. The problem is output valves need output transformers and high voltage supplies which means another large transformer. Some have used pre-amp valves generating sub-watt levels into a load but this is not the same as having an output transformer and dummy load. As it happens I am just about to relaunch my Class A single ended valve amps. regards Dave

[quote name='The Burpster' post='93818' date='Nov 24 2007, 04:28 PM']Dave, Match the impedence of the p-ups or teh p-ups to pre amp? Bob.[/quote] p-ups to pre-amp. Dave

[quote name='The Burpster' post='93156' date='Nov 23 2007, 08:07 AM']DH, There is a thread in (repairs IIRC) about a BCer that has got some new pups, and they have an extra earth when output. When he has contacted the maker, they have quoted that the extra earth is for on-board pre-amps with a buffer. I have a rough idea what a buffer does, but my question to you is:- Have you any idea why some new on-board pre-amps have one built in? and assuming that most amps pre amp stages have one, or seperate pre amps have one, what would there be to gain by having one in the bass? Bob.[/quote] I think they are taking about a balanced load buffer and putting one in the bass will reduce the noise and help match the impedance. Dave

[quote name='Crazykiwi' post='92775' date='Nov 22 2007, 02:39 PM']I've moved this to DHA's forum, he might be able to assist too?[/quote] I agree with Warwickhunt on this one. Needs to go into the shop for repair as it sounds like a dry joint somewhere in the amp, could be anywhere but my guess would be to look around the power supply first. This needs to be fixed by someone that understands valve amps as poking around in there might be the last thing you do. Dave

[quote name='pete.young' post='91504' date='Nov 20 2007, 02:38 PM']Thanks Dave, that makes sense. They have different kits depending on whether it's cathode bias or fixed bias, and there's another add-on for amps with a separate supply for the screen. I dont have schematics for the Burman but I guess it takes the screen voltage off the plate. It's probably time for me to go and find someone locally who can poke about in the amp innards and confirm this![/quote] Hi, The different kits for different bias tells me that they must change it depending on the plate voltage, neat trick. I have worked on an old Burman and I am 99% sure it's just a fixed bias and the screen voltage is just taken via a resistor from the plate. It's really only hi-fi amps that have separate transformer taps for the screen as it's too costly for distorted guitar amps! Let me know if you go for this as it sounds very interesting Dave

[quote name='pete.young' post='90761' date='Nov 19 2007, 12:12 PM']Hi Dave, Have you ever come across Power Scaling, from London Power [url="http://www.londonpower.com/pscaling.htm"]http://www.londonpower.com/pscaling.htm[/url] ? I was wondering if it might make my Burman guitar combo a bit more useable.[/quote] They don't give a lot away as to how they do it but reading between the lines I think they may be reducing the plate voltage but keeping the current the same by dumping the power or 'power sharing' if you like between the load and output valves. I run my valve pedals at lower plate voltages and it's fine, I believe this is what they may be doing as well. I just can't work out how they control the bias but I am sure they must have fixed this or it would not work at all. Looks neat and could be a good solution for your Burman. Dave

[quote name='BeLow' post='90124' date='Nov 18 2007, 09:01 AM']Actually DHA - who hand makes effects and now amps previously offered the use of his 'barn' for a get together (he is in Devon also) and as an opportunty to try out his gear as well. This seemed like a great idea at the time but we never quite got round to organising it - talking back in the original Bassworld era here. He may still be willing. I am still very tempted to go for one of Dave's optical compressors so I would like to wend my way up to see Dave at some point, top notch valve based unit, built less than 30 miles from the doorstep just seems to good an opportunity to ignore.[/quote] Hi, I am still on for a SW bash in the barn but needs to be in the summer. It's too wet and cold now plus I bring some of the animals in for the winter. Dave

[quote name='Sibob' post='89936' date='Nov 17 2007, 04:38 PM']How much extra would the unit cost with a DI in a larger box? I'm only asking about the DI because the Punch Factory has one, and in one of the band situations I'm in, i control my front of house sound rather then a sound man. Cheers Dave Si[/quote] I would have to have a think about it but about £35-£40 at a guess. Dave

[quote name='Crazykiwi' post='89790' date='Nov 17 2007, 10:33 AM']You can always ask DHA for some help if you need it, this is the sort of thing we set that forum to handle. Let me know if you would like the post moved.[/quote] Hi, Try pushing the black lead against the earth and see if you get any noise when playing? If it fell off somewhere there must be a cue as to where like a blob of solder, broken wire or a pin on a pot not connected anymore. Dave

[quote name='Sibob' post='89881' date='Nov 17 2007, 02:13 PM']Hey Dave How would you compare this unit to the Aphex Punch Factory? I use the Aphex and really love the sound actually, but its built like a cake! And after just one tour and 6months of gigs 3 times a week its starting to get buzzy/loss of signal on the ins/outs. I don't even stamp on it, it just remains on, on top of my amp. Would it possible to add a XLR DI signal output? Cheers Si[/quote] Hi Si, I have not used the Punch Factory so not the best person to ask, I also never compare to others. But, there are a few owners out there now who might be able to help. I would not be able to fit in a DI into that box and also the price would go up if I could. I could do it in a larger box. There is a nice external one that Maplin do which would do the job. Dave

Hi, We now have a lower cost version of our valve compressor which I hope may be of interest. [url="http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=130174755207&ssPageName=STRK:MESE:IT&ih=003"]http://cgi.ebay.co.uk/ws/eBayISAPI.dll?Vie...E:IT&ih=003[/url] Dave DHA

[quote name='elom' post='89127' date='Nov 15 2007, 08:41 PM']Shall we have a Westcountry mini-bash then?[/quote] Good idea, I'm in. dave

[quote name='Buzz' post='88206' date='Nov 14 2007, 02:17 AM']If it's anything like the way DHA do it, it'll reduce the output from 3w back down to line level which is then sent to the poweramp. Nifty way of getting pre & power tube noise and serious wattage for much cheaper.[/quote] Sounds like we are doing the same thing. The signal to the solid state section is from the valve output transformer where it drives a dummy load. This way the signal is coloured with valve output warmth and the super clean SS amp just acts like a flat PA. The dummy load is important as this effects the tone as well. The dummy load is used to replace the valve driven speaker and using just a resistor will work but not that well as speakers also have inductance and capacitance. This means speakers sound different at different frequencies, resistors don't. We use a 3.5" speaker inside the VT5-400-Bass as a dummy load to get around this issue. We have plans for 700W and 400W+400W stereo versions coming soon. We also do a version with no SS power amp (one already sold to a BC member) for use with a PA, an existing power amp or replacing a pre-amp in an existing amp. What price is the Warwick Tubepath? Maybe we are seeing a new trend in bass amps, I hope so Dave

[quote name='Stewart' post='87872' date='Nov 13 2007, 02:23 PM']Easiest would be to make up a cross-wired jack plug and socket (to reverse the phase of the jack output)[/quote] It's not a bad idea but you need to be careful as by doing this the outside (metal part) of one of jacks will be positive with respect to earth. At 400W this is 120Vac into 4 ohm so this will mean touching the jack will make your eyes water for a while. Dave

[quote name='Crazykiwi' post='87854' date='Nov 13 2007, 01:55 PM']Dave I've got two outputs on my Trace V8, one is a jack, the other is an XLR. I've got an issue where the output of two speakers is considerably lower than when one is plugged in and its been suggested that there might be a phasing issue. I'm wondering if the XLR cable is wired so that the cabs are out of phase. Do you know of any quick (ie. solder free) ways to change the phase relationship between speakers being fed by the amp?[/quote] A quick way to check if it's a phase issue is to point the speakers at each other and move them towards each other, if they are out of phase they will lose volume as they get nearer. Not easy to do if the speakers are in the same cab I grant you! If this is the case then you need to check how the speakers are wired visually or with a meter. There should be a + and - tag on each speaker. The XLR cable should be wired 1 to 1 so I don't think it would be that. But first we need to find out if it's a phase problem. Dave

[quote name='pnefc42' post='87845' date='Nov 13 2007, 01:28 PM']Dave You have PM[/quote] Thanks, PM back

[quote name='MoJoKe' post='51789' date='Aug 28 2007, 02:54 PM']Sorry I didn't spot this one until just now! I've been away for a couple of weeks. I still have nothing permanent, so interested in exploring anything, particularly blues! Get in touch by all means!! I''ll PM you my contact details[/quote] Hi MoJoKe, Timface is leaving the Weekend Rock Stars which is a shame but we wish him luck with his new venture. So we are looking for a replacement, are you still available? We did speak about this a while back which I hope you remember. Dave

The Weekend Rock Stars are looking for a new bass player in Devon. We play classic rock and blues and get lots of work and have a good following all over Devon. We do it for fun but the money is nice so it's important we get someone that fits. We have stopped gigging while we find the right replacement but we are booked new years eve and have several larger gigs booked for next year. We also want to get in the studio this year if possible. ring Dave (DHA) on 01805 603369

[quote name='Nate' post='87545' date='Nov 12 2007, 08:03 PM']Hey... I was working at Music Live and had a go on the VT5. What a great sounding amp! I didn't get long but the grit I managed to get out of it was great. Very Pokey and had plenty of bottom end, Well done Mr DHA![/quote] Thanks Nate, It was very nice to meet you and for me and my mate John (both lead guitarists!) you stole the show in terms of demos on a stand. Dave

[quote name='paul, the' post='87337' date='Nov 12 2007, 02:32 PM']I bet you hesitated over posting that, Dave. *zombie drools*[/quote] I was a bit worried for a while when it didn't get a reply right away. May be we should start a thread about the stereotypes in bands? My amp goes to 11 you know. Dave

Hi, I had a great time meeting and talking with customers and BC members, nice chat with jwbassman. Very nice to meet Alan of ac guitars and John East. Big thanks to Alfa Dave for helping with the stand. Very pleased that Sug liked his VT5-400-Bass amp which he picked up at the show. I don't normally talk to many bassplayers as I play lead guitar and the drummer is the only one that will talk to the bassplayer which is the best way I find. But, it was nice to see some of you are almost normal so I must make more of an effort in future. ONLY JOKING! Dave

[quote name='hipbass' post='85033' date='Nov 7 2007, 05:51 PM']My EVO 2 300 has an almighty hum which more or less disappears ,but not entirely, when I plug in my bass;;The sub harmonic works not at all...Anyone else had similar problems? Anyone else still using Ashdown!!..Would also appreciate any thoughts on the Superfly head....Ta.[/quote] Most amps have a switching jack for the IN which shorts the signal to ground to stop hum when there is not a guitar or bass plugged in. The jack could be broken but this is simple to fix. The sub harmonics may be a separate problem. Dave

[quote name='ped' post='84948' date='Nov 7 2007, 03:14 PM']Hi Dave, I was there on Saturday and did watch a couple of people try it out through the Berg 610. From what I heard it sounded very full but quite dirty - we had a go at calming it down but were not too familiar with the controld and so on - we found that by turning the 'Bright' switch off and easing back on the treble it warmed up very quickly, so I should have liked to have spent longer with it and exploring it. It struck me straight away as a fascinating piece of kit.[/quote] Hi Ped, Thanks for the reply. Yes, I guess it does not do SS clean, starts at warm and ends up at high gain. I can tweek it a bit but I am thinking it's not intended to be used for very clean. Shame I could not make the Sat or I might have been able help a bit, one of the issues is the controls are very interactive which is a good thing but it takes a bit of effort to find what you are looking for! I am building a 2 stage version for a BC member now and I think the single channel version already has the gain required for that. So, I will drop a valve stage on the single channel version and use it for the hi gain channel. This will clean it up quite a bit but still leave the high gain option. regards Dave

Hi, We have a stand a Bassday in Manchester this coming Sunday and it would be nice to meet a few BC members. Anyone going? We will have the VT5-400-Bass amp plus bass pedals on the stand. Dave