DHA

[quote name='Sugden' post='66697' date='Sep 28 2007, 12:37 AM']Hey dave thanks for the pics looks like its coming along swiftly. Going to be a nice full box by the end of things.[/quote] Please check out the special offers section for an offer to BC members on this amp. Dave

[quote name='Alpha-Dave' post='66385' date='Sep 27 2007, 12:41 PM']Ah, that makes sense of course. While trying to hold a strainght face: is there any reason for the massively long shafts for the control knobs? On the previous rack pre, I thought you used normal sized ones, with lots of wire connecting them to the main board, do you intend to mount then directly onot the boards this time?[/quote] It's just a lash-up to try it out and I have not cut the shafts yet. The pots will be mounted on the front panel. Dave

[quote name='neilb' post='66378' date='Sep 27 2007, 12:31 PM']Dave Cant see the muffplate in your picture. I see you are going for the cocktruss array idea....good old boy![/quote] Our muffplate is never shown in public as we don't want Marshall, Fender or any others nicking it. Dave

[quote name='Alpha-Dave' post='66376' date='Sep 27 2007, 12:26 PM']And all those bits fit in that little pedal, cripes! it's a tardis! [/quote] Not quite here is the 2U rack. Just the VT1-MK3, VT1-compressor, VT1-Bob-the-blender, 400W power amp, power amp power supply and few other bits to add. [attachment=2496:PICT0031.JPG] Dave

[quote name='BigRedX' post='66288' date='Sep 27 2007, 09:37 AM']No pics... no amp... I'm sure bits on a bench would be pic worthy. Think of it as the equivalent of the raw wood shots at the beginning of a bass build.[/quote] Okay, talked me into it. [attachment=2495:PICT0029.JPG] The larger transformer is the mains one the smaller is the output transformer. There is a 12ax7 pre-amp/driver valve and a Mullard EL90 output valve which is part of the EL34, EL84 family and sounds great IMHO. The VT1-Purist-Pro is acting as the main pre-amp and will push the output stage into overdrive with ease. The finished amp will have a 400W SS power amp, DI and Line out, VT1 pre-amp, tone controls, valve blended Fx loop, valve compressor and tuner mute. Dave

[quote name='nedsbeds' post='66111' date='Sep 26 2007, 08:41 PM']it's not a build thread without pics [/quote] It's just bits on the bench at the moment. I will do pictures when it goes in to the box Dave

I ran the valve stage power amp up today into a 4x12" - after a bit of mucking about it sounded great and even better when I used a VT1-Purist to overdrive it and acting like as pre-amp. It goes into a nice warm output distortion at about 1/2watt, very rich in harmonics. The next stage is to DI the output and also reduce the 1 watt back to line level to drive the 400W power stage. Dave

[quote name='redroque' post='66086' date='Sep 26 2007, 07:59 PM']I think you would need 3 phase for this so it's probably impractical as there aren't many stages with a 3 phase supply.... [/quote] No need for 3 phase as it has a built in atomic reactor to power the cocktruss bias anyway.

[quote name='neilb' post='66074' date='Sep 26 2007, 07:38 PM']Abso-bloodly-lutey Dave....exactly the design I would use. I would also attach a silicone nangeflaglet to the output of the reverse cathode muffplate so that the inverse current can draw sufficient voltage from the cocktruss array. What do you reckon? PS - Dave, loving the Purist VT1 mate. !!![/quote] Want a job?

[quote name='Sugden' post='65550' date='Sep 25 2007, 09:25 PM']Ooo I knew id ruin my fun taking out that second channel. Im sure 5 will do me fine though. Shame VT6 had a lovely ring to it. Cheers dave, glad your having fun making it always a good sign to get a labour of love Hope you'll want to let it go when your finished. O I didnt mention its coming in the blue with red spatter finish which I really took to the first time I saw a picture of it on the VT bass rack. Do I get to have lots of flashing light dave? Im abit of a sad old man loving blue flashing lights.[/quote] You will have to wait and see what father chrismas brings (early) if you want flashing lights. Dave

[quote name='Sugden' post='65452' date='Sep 25 2007, 05:56 PM']2U rack head VT6-400 - 400W single solid D class power amp backing up an all valve 1-4watt bass amp It’s packing 6 valves in total including the single 1W output stage. There will be a 2W output transformer in the valve output stage to help produce valve output distortion. There’s even a mullard in there.[/quote] Sorry to correct you Sug but it's a VT5-400 now that you are not having the overdrive channel. So that's 5 valves. That's 1 (2 stages) in the compressor, 1 (2 stages) in the Fx loop, 1 (2 stages) in the pre-amp and 1 (2 stages) in the driver. The output valve is a NOS Mullard EL90 which I would bet is older than 3/4 of the BC members. It is running in pure single ended Class A mode with Cathode bias. It will drive a speaker or the internal dummy load when the speaker is not connected. The 400W power stage picks up the signal from the dummy load which is reduced back to line level. So its the valve power stage signal after the output transformer that is sent into a very clean SS power stage. I am having great fun building this amp, pictures soon. Dave

[quote name='alexclaber' post='65492' date='Sep 25 2007, 07:20 PM']Wow, sounds quite remarkable! Whose Class D module will you be using? SMPS? Alex[/quote] It's a UcD400 OEM from Hypex Electronics in Holland. They also do 180W and 700W modules which will fit as well. I had a good talk with Hypex today and they are very interested in the application and have given me a good deal. Dave

[quote name='OldGit' post='63355' date='Sep 20 2007, 10:23 PM']Oh yummie .. Like this then Dave .. What does the "optical" bit in the name refer to?[/quote] Hi, The optical bit refers to the control circuit. I use an LED and an LDR (light dependant resistor) - the LED lights more or less depending on the amount of compression and decay you set, this changes the resistance of the LDR which in turn acts as a volume control for the valve. I use 2 LED/LDR circuits which gives the hard/soft settings the only difference is the colour of the LED as ones blue and the other green. The LED's are driven by an op-amp control peak detection circuit, it's a complex design using 5 two stage op-amps (that's 10 op-amps in all!) and 2 valve stages for the signal path. As many of you know it's taken me over a year to get this the way I want it. The blue LED on the outside of the box is really showing you what the LDR's are seeing. Using an optical interface reduces the noise that voltage controlled op-amp designs have problems with. All the top studio compressors are optical. Yes, yours is like the picture but there is an extra switch (boost) on the top plus a boost pot on the back. I am testing the second batch today and I will post what I can later, so most if not all will see their compressors tomorrow or Monday. Dave

[quote name='OldGit' post='63341' date='Sep 20 2007, 10:04 PM']Sounds good Just waiting for mine to arrive .. I hope mine will be wearing the pretty coloured box though OG[/quote] Yes, Yours is nice and bright Dave

[quote name='Crazykiwi' post='63325' date='Sep 20 2007, 09:13 PM'][attachment=2414:DHA_VT_1...mpressor.jpg] [b]Dave Hall Amps VT-1 Bass Compressor[/b] [i]Features: 7 [/i] This pedal features the following: Controls: Compression threshold, Decay, Level control, plus impedance pad and boost level Switches: soft/hard compression ratio, boost on off, effect on-off The boost control wasn't necessary for my preferred settings because I got better results through not using it. But that doesn't necessarily mean another player might not find it useful. Hard/soft ratio is useful for helping to turn the pedal from a compressor to a limiter for use, say, after a synthbass pedal or similar source of potentially spiking audio signal. [i]Sound Quality: 7[/i] I tried my Smith BSR5-GN and Celinder Update 4 through a super clean sounding GK RB700 1x15 combo. OK, lets be honest, this pedal isn’t going to put Avalon out of business, but this pedal isn’t at an Avalon price either. Through my GK, its possible to generate noticable levels of hiss with extreme settings, but when used in moderation the pedal is perfectly acceptable for live use. Using good quality cables makes a [u]significant[/u] difference as well. Do NOT use cheap Maplins-type cables, they will act like antennae and you’ll end up sorry! I am also aware that my GK generates a significantly glassier tone than many other of the bassbash rigs I've tried. So its worth bearing that in mind when I comment on noise or hiss, it might well be that most members wouldn't notice much. The boost added an edge to the tone, in the same way as when the compressor was off. But it also increased hiss so generally I left it off. After mucking about a bit with extreme settings I settled on having the boost off, compression threshold at 9 oclock, decay at 1 oclock and level at 2 oclock. I ended up with a subtle compression which didn’t colour the sound too much, the noise levels were very low and the blue LED showed me that the effect was still happening. The general effect that was full, smooth and free of spiky edges . I also have to confess that knowing what the controls do is one thing but knowing how they interact is another entirely. There are many permutations of loudness to be had by varying the IP pad knob against the boost control and level. For the purpose of this review, I aimed for a sound I felt I could use every rehearsal. With the Smith, the VT-1 compressor evened things out a lot, and reduced some of the lower-midrange boom. On the Celinder, it fattened up the midrange very nicely and took away some of the brittleness of the Lindy single coils. I could transfer from slap to fingerstyle with very little loss in punch or volume yet the sound wasn’t coloured excessively either. There was plenty of snap coming through the amp when the compressor was engaged, and no distortion unless extreme settings were used. The one thing worth bearing in mind is that because this pedal is true bypass, you will get a loud pop, the first time you step on the on/off switch after power up. I recommend turning on the compressor before the amp or at least while the amp has a mute switch active. [i]Reliability: N/A[/i] I haven’t tested this pedal in anger yet, but I’ll see what other members think of it in due course. [i]Customer Support: 9[/i] Dave’s on BC all the time, and the pedal comes with a 12 month parts and labour warranty so long as you don’t subject the pedal to silly extremes he'll be there for you. [i]Overall Rating:[/i] I’m going to rate it a 7.5. Obviously it’s not as quiet as a studio valve compressor, but its not as bad as the Ibanez CL10 I once owned and certainly in the top quarter of all the pedal compressors I've tried. The Trace compressor is quieter but I think the VT-1 pedal is more subtle and that valve works a bit more magic on your tone. The key to using the pedal effectively is a little goes a long way. The LED which lights up when the set compression threshold is reached lets you know with certainty how much compression is happening and when its in effect so you can see for yourself when the pedal is doing its job. Try a little tenderness and it will reap dividends, I was very satisfied with the pedal and plan on making it a staple part of my live rig.[/quote] Many thanks Steve, dave at DHA

[quote name='neilb' post='58376' date='Sep 10 2007, 06:45 PM']As you know I run a Superfly into two 2x10 cabs. The sound for me is fine but it lacks warmth and growl sometimes. (To be expected I suppose as its a Class D SS amp). So...... I would like to get a valvey slightly overdriven sound and I obviously cant get it with the normal pre sets/EQ on the amp. Im thinking of a DHA Purist Bass overdrive pedal to add to my set up. Would that give me what Im after? Im a bit of a simpleton when it comes to effects, I have avoided them in the past. Any comments from users of DHA stuff (or from Dave himself!!!!) would be welcomed.[/quote] The Purst is really just a valve pre-amp and I think it will do a good job for you. But I would say that! So please get comments from DHA users. Dave

[quote name='dirtystatic' post='57953' date='Sep 9 2007, 11:06 PM']I notice youre already selling a fuzz pedal on your site, how does that fair with bass?[/quote] Hi, Yes the Fuzzy Feeling, it's the same pedal that I am thinking of offering as a kit. It works well with bass and there are few out there already being used as a bass fuzz. Dave

[quote name='dirtystatic' post='57647' date='Sep 9 2007, 10:26 AM']by kit do you mean individual components for self-assembly?[/quote] Could be just the bits or even a part built and tested version, you just put in a box. Dvae

[quote name='MoJoKe' post='57251' date='Sep 8 2007, 12:05 AM']The VLE definitely seems to have a more positive effect on my passive Precision, less so on the Wal and DE5, but the both actives are [b]very[/b] active! Has anyone any experience with the DHA Valve units...? Dave, perhaps I could have a tryout? [/quote] You would be welcome to try one out. give me a ring Dave

Hi, I have a tonebender based design called the "Fuzzy Feeling" which I am think of releasing as a kit, anyone interested in kits? Dave

Thanks Jim, Just so you all know, Jim's rack is a custom design to his specification and we are happy to quote on any "pick and mix" designs based around the features in the VT5. Dave

[quote name='stevebasshead' post='49523' date='Aug 23 2007, 01:36 PM']I was right, they were GT's and Sovteks - score 1 for my memory brain cell!! However...I don't think I'll bother with trying the ECC82's at a rehearsal. I tried it last night at house volume levels and the sound seemed a lot weaker, kinda [i]insubstantial [/i]with a full complement of ECC82's. The level also dropped significantly more than I had been expecting. So...new plan is to put the GT ECC83's back in but maybe not the Sovteks - I've got the EH ECC83's from my DHA spare at the moment so I think I'll pop those in instead.[/quote] Hi Steve, You know the GTs are most likely Sovteks anyway GTs don't make valves they just rebadge same as Mesa, Fender, Marshall and EH. But they do get custom designs made for them which are just versions of a 12ax7/ECC83. Since EH took over Sovtek the quality has gone up as they used to gain test all valves and the best ones went to Fender, Marshall, etc. and the not so good ones went out as Sovteks. They now go out as EH but as I say they are much better. I noticed about 1 year back that I was not having gain problems with the EH valves as I was finding about 1 valve in 50 was not useable in my pedals. Dave

[quote name='stevebasshead' post='48461' date='Aug 21 2007, 06:13 PM']Hi, I've got an SVP-Pro preamp (grey hammered finish) with the stock valves in it except for the unbranded ECC82 which I've swapped out for a Jan Phillips ECC82. Thing is, I've got several more lying around unused so what would happen if I replaced the remaining ECC[b]83[/b]'s with Jan Phillips ECC[b]82[/b]'s ? Would it simply sound different (and if so in approximately what way) or just be less efficient or something else? I know from swapping ECC83's for ECC82's in my DHA that I liked the change but in the DHA they're purely for providing OD/gain whereas I'm not sure what function the valves perform in the SVP, so I'd rather not experiment in ignorance I'd appreciate any advice, thanks in advance. Steve.[/quote] Hi Steve, It can't do any harm to swap valves. There is likely to be less gain and maybe even level but there will be a better fatter tone I would expect. You can always swap them back if you don't like it. Dave

[quote name='MoJoKe' post='8688' date='May 29 2007, 05:13 PM']Soul, R&B, Funk, Blues, R&R. well experienced Ex-Pro Mid 40's bass player in need of a new challenge!! I've been in Newton Abbot for a year now, and took a while to find my feet and start looking for a band. I joined a bunch of amateurs, did one gig and then left. I'm not looking for pro work again, just a couple of gigs a month would be fine, but must be really good quality!![/quote] Hi, Did you find a band yet? Looking for a bass player for a new Blues band based in Devon. We are all old boys and some play in other bands. Dave

[quote name='Alpha-Dave' post='40136' date='Aug 1 2007, 06:38 PM']Warwick for all 3 in 1. Otherwise ACG bass, DHA/Torres amp, BFM cabs and DR strings. I like acronyms.[/quote] You have one of my amp designs from Torres? Dave