DHA

[quote name='Cuzzie' timestamp='1496497633' post='3311921'] The options I see it are as you describe, which if going for a simple circuit put you into Quilter bass block territory for simplicity, or even Handbox (but they are quite big) or with a drive circuit that is looking at Genzler magellan or Darkglass territory, Tech 21 VT etc. If you wanted to go for pure clean power then it's the Demeter Minnie 800 or Jule M700 power amp for non rackable stuff I would say are out there in front. Not sure what other people are doing, but if people already have pre-amps they are happy with, then a small portable simple power amp to replicate faithfully their sound may be the way forward which could also double as a headphone practice amp, or DI without a cab. Personally I have a valve pre-amp in the Two Notes LeBass, a Cali76 and a Hartke VXL bass attack pre-amp, and I may well get the Tech21 dUg pre-amp pedal when it comes out in the next year, so I probably have all the sound modulation I want, but a small power bundle similar to the Quilter Micro45 or as close as can be is a definite pick and go option [/quote] I take your point about pre-amps being a personnel thing but a clean power amp would be just one more of many already available. I would make the valve drive switch-able so it could be used just as a power amp with active EQ.

I started a thread in the effects forum asking for help about a new pedal format I want to do. The thread went off subject and moved onto mini power amps, got me thinking. A few years ago I did a few rack-mount bass amps with 400W and 700W Hypex modules and a 5W valve pre-amp and valve output stage. In those days Hypex power amp modules only worked with linear power supplies which meant a very large and heavy transformer but they now have a switchmode PSU which does not require a transformer and is quite small. They even do modules with the PSU and amp on the same PCB now. My idea after requests on the other thread --- A VT1-EQ-DI-Bass pedal design with 180W or 400W or 700W power stages. Would be a mains supplied self contained unit as small as possible. All the fun of a valve amp and very high volume but lightweight. There are mini power amps out there already but is there room for one with a valve pre-amp? How much would people be willing to pay? is there a need? Its a big project and would need investment as the product would need development, designing, manufacturing, marketing, CE mark, etc. So something I would not take on unless it make sense and there is a market. I look forward to your comments

I will start another thread about power amps, I have a few ideas Dave

[quote name='Rumple' timestamp='1496341531' post='3310740'] That's a shame but understandable. [/quote] Might well do one in the future (MK3) but I would have to totally redesign the PCBs and maybe even switch to SMT components (surface mount technology) which would mean I would have to subcontract the manufacture.

[quote name='Al Krow' timestamp='1496340233' post='3310728'] Sorry for any confusion - I'm aware that dBs are a measure of sound volume, but I was referring to physical volume i.e. compactness when I spoke of the 1970 cc package. Anyway not to worry, thanks for humouring an ex (long time ago) physicist [/quote] sorry did not want to offend. Will be interesting to hear the reviews of Elf

[quote name='Al Krow' timestamp='1496338886' post='3310717'] Haha very true! It's just sometimes the accepted norm isn't always the correct one...Aristotle, Newton, Einstein...Next? Final punt on this...the Demeter Minnie 800D churns out 800 Watts in a 1970 cc package. Following the laws of physics shouldn't it be possible to produce a 200W amp in something correspondingly smaller that would fit easily onto a pedalboard [i]and[/i] be better than the Elf? [/quote] watts are not a measurement of volume, dBs are. The trick that switchmode amps use is that they do produce 200Ws but they keep switching it off and on so fast that humans can't hear it happening but its the total on time that you hear not the peak wattage while its on. Thats why valve amps sound so load as they produce much larger harmonics as they approach clipping, producing more power (watts) into the load (speakers). anyway, its looks a great amp and not the sort of thing I would consider designing as not my thing. Its all about personnel taste. I think you will find that 200W valve amp will sound twice as loud as the Elf.

[quote name='Rumple' timestamp='1496337968' post='3310706'] Looks great are you doing a similar mocked up layout with the VT1 DI EQ? [/quote] I will be doing a silk screen version of the VT1-EQ-DI-Mk2 but with the current PCBs it will be impossible to get the switches on the top and the valve inside without using a larger box. I can add a Di to the VT1-Std

[quote name='Al Krow' timestamp='1496336461' post='3310689'] Yup - completely fair point. But would it not be possible to have an off-board power supply with heat sink built into that? In the same way that mobile phones don't have large built in chargers and my HP desktop has its power supply transformer external to its consequently more elegant body? It's a trade off that most consumers seem to be willing to accept. My counter is that Trace Elliot have already done it with their Elf in a package that is no larger than a large pedal (just 600 cm3). I kinda feel you could make something a lot more desirable. Anyway I know I'm just a happy amateur and appreciate that I am way out of my depth here! [/quote] The heat sink is for the power amp not the power supply. I think the Elf must be a switchmode or digital power amp design, my experience with them is that they are not very loud compared to the standard designs of the same wattage. Might be wrong but the laws of physics are very hard to change.

[quote name='Al Krow' timestamp='1496334322' post='3310662'] So Dave - the mini power amp pedal is a definite non starter then? If it's a case of funding by pre-orders I'm sure you would have 100+ from BCs alone or we could maybe do a BC crowdfund for your much loved Devon based crew [/quote] Making a high power "mini" amp is not a problem, making its power supply and keeping it cool is. Watts out can only come from watts in so the power supply would have to be separate and pretty large. As power amps are not 100% efficient (nothing is) then there will be heat generated so the heat sink required would most likely be 3-4 times larger than the amp. I think if it were possible then someone would have done it already

[quote name='paul_5' timestamp='1496331936' post='3310626'] Regarding the artwork I'd have to agree that most sound engineers refused to take the DI out of my DHA because they were afraid of what it would do to their speaker. On the other hand I turned up at a festival with it on my board and the engineer took one look at it and said "Oh, a Dave Hall, I'll take my feed from that!" Swings and roundabouts. [/quote] just a space model of the new VT1-Std-Bass Mk2, will be silk screened. Controls are I/P level, Gain, Level and Colour - Bright and Colour switch. The jacks and power connector are at the top of the pedal. 120x145x60mm [attachment=246442:IMG_1706.jpg] [attachment=246440:IMG_1704.jpg] [attachment=246441:IMG_1705.jpg]

[quote name='Sibob' timestamp='1496324403' post='3310514'] Yeah the Elf is the closest thing to what you want I think at the moment, although there is another thread where a member is having some real issues getting their pre-ordered Elf. It was announced at NAMM (Jan 2017), preorders taken just after that, and now availability is being touted as end of July, having been pushed back on each subsequent date set. By all accounts it sounds fine, just depends whether they actually manage to get it out or not lol. I'm not sure I'd say the Q45 is "significantly smaller" than a Boss pedal, the Q45 looks to be a 1590B size (MXR) which is a few MM smaller than a Boss pedal. Anyway, I'm picking hairs . I guess one day we will get super mega small amps for not much money......but it will always be the same.....someone will talk about 'valve amp heft' Anyway, this is off topic, continue about DHA. I imagine that if you're looking for a more commercial path (dealers etc), then tidying up the artwork (I was a fan but others may see it as too 'homemade') and focussing each pedal is a great start. Obviously each original DHA pedal had a lot of functionality and a lot of options. Strip those ideas back to say 3 or 4 pedals that all have specific functions, 3 or 4 controls perhaps. A drive pedal, a DI pedal with EQ & drive, a headphone amp etc etc (just as examples). Keeps it easy to digest. Then if someone wants something extra, a control added here, a switch added there, original splatter artwork....you can offer that as a 'custom shop' option just through you. It's a model a lot of builders employ. Just my 2 pence Si Cheers Si [/quote] Thanks Si working on 2 models at the moment that will have silk screen - one will be my the best selling VT1-EQ-DI-Bass MK2 and the other a version of the VT1-Std-Bass but with the valve inside and switches on the top. Making one at the moment so will put pics up later. I agree if people want custom features then I can add them

[quote name='JimBobTTD' timestamp='1494157324' post='3293671'] I can echo the comments about power supply... I had one DHA pedal, a VT1-EQ-Bass-Drive that I bought off someone here. It sounded great as an overdrive and I used it to warm up my amp and, later, to give an OTT distortion when I did a few grindcore gigs. However, I was never fully happy with it as it was huge and needed its own power supply. The headphone out was noisy to the point of being unusable and, if I remember correctly, I had to have its volume on 0 or else it put a huge amount of noise in the signal. When the DI went noisy, I decided I had had enough and moved it on at a low price due to its defects. As a pedal in its own right, though, it was very good albeit a touch noisy. I would have kept it if not for the power needing to be 12v AC (if memory serves me well). I was not alone with the headphone out problem, although I could not find any other comments about the DI. The paint job was never a problem with me. However, when combined with the headphone out not working and the DI going south, it made the whole package look amateur. Switches on the sides look like repair jobs waiting to happen. Valves sticking out of holes look like poor planning (sorry, Dave, it is nothing personal) and I remember reading someone here in another thread complaining about them getting broken when moving the pedal about. [/quote] The older VT1 was quite large but I swapped to the smaller VT1-EQ-Di-Bass MK2 a couple of years back. I also changed the headphone design and fixed the noise on that. Sounds like you had other issues with yours as its not possible for the headphone to introduce noise into the signal path unless there is a fault. The supply is 9-12VDC not AC as this would have damaged the pedal. My pedals are very low noise if used with a correct power supply.

[quote name='TPJ' timestamp='1494171363' post='3293760'] +1 I use a Bob the Blender as just a valve stage at the beginning of the chain. A smaller version would be great. I like the orange paint schemes but not so much the white ones. Also, I noticed the boost switch on the pedal reacts differently with different basses. One bass will be smooth and warm with the boost off and a little harsher and firmer with it on, and another bass will react opposite with it being harsher with the boost off and warmer with it on. What might cause that? [/quote] Its just a clean boost so should not make any difference. Most likely the VT1 valve stage is reacting differently and having the boost on just allows you to hear it. The input level to the VT1 does make a difference as you would expect with a valve as it breaks up.

[quote name='Thunderbird' timestamp='1494191140' post='3293956'] Well new tube ordered will update the thread when I fit it [/quote] won't be the tube, power supply every time. worst case is that someone has plugged a power supply in with a higher voltage than 12VDC and damaged the voltage doubler circuit and caused to to change frequency to something you can hear, seen that before.

[quote name='dannybuoy' timestamp='1494110546' post='3293404'] I had one of your old VT2 pedals with the colour and clipping switches but never used any of them as it sounded best stock; in fact I just used the pedal like a VT1 std/purist. I would like to see a barebones VT1 with just gain and volume (and maybe input pad) in as small a box as possible. [/quote] a mini VT1...... yet another good idea, thanks

[quote name='eddiehoffmann' timestamp='1494113007' post='3293417'] I think it's not a deal breaker for someone who's only thinking with their ears. But you might attract more "average" costumers with a prettier package. [/quote] nail on the head as they say.

[quote name='elephantgrey' timestamp='1494109897' post='3293399'] I would vote for the blend. More options are always good. If some don't want it, they can keep 100% wet, and it will still be there for those that do. Also, I've always dug the whole paint splatter and hand written thing. Love it on my blend loop. [/quote] first one to talk about the paint job! maybe its not such an issue as I first thought?

[quote name='dannybuoy' timestamp='1494102482' post='3293343'] I don't see the need for a blend. On full range low gain devices, they only serve to dilute all that delicious tone. They are only useful on heavier distortions or drive circuits that drop low end in my experience. I know you can crank a VT1 to get something approaching a fuzz, but I doubt that's how most people use theirs. [/quote] I tend to agree about blend as it should not be required on low/mid gain but I get asked a lot about it. The issue with high gain is compression which is both a good and bad thing. It does reduce the bandwidth which makes the overall tone sound narrow so adding a blend on higher gains is useful.

[quote name='paul_5' timestamp='1494098906' post='3293313'] I used to use the headphone and line in function as a home practice amp and found it really, really useful. I sometimes wished it had a blend and a hpf so that I could keep the lows clean and just add some hair to the top. Just my twopenneth [/quote] thanks, could a high end all functions version and a lower cost no frills one as well

[quote name='dannybuoy' timestamp='1494098643' post='3293312'] If you are going to drop the headphone amp and aux in, maybe make that a separate pedal? There aren't many options out there for simple compact headphone amps; the EHX one has no aux in, the PJB Bighead is great but expensive. [/quote] mmmm.. could be an idea, will think about it thanks

[quote name='eddiehoffmann' timestamp='1494096688' post='3293292'] Would that be ok? Thanks for taking time to reply too, man! [/quote] Looks like 300mA, a VT1 takes around 320mA so no unless you use the current doubler feature.

[quote name='Skybone' timestamp='1494059628' post='3292881'] I' have thought that it would be OK to use the 18v supply into the 12v pedal without any step down in voltage. [/quote] If its one of my pedals then 18V will blow it up, think that would be the case with most others. A voltage regulator circuit or DC-DC converter is the only way

[quote name='eddiehoffmann' timestamp='1494094917' post='3293268'] I didn't know that. So is there an internal power pump now? And would it be ok to run it off a T-Rex Fuel Tank Chameleon? [/quote] Always has been a voltage doubler in my pedals to get a higher plate voltage. I switched to negative centre a few years back so people can use "Boss" type supplies if they wish. There is a loss in headroom when running at 9V instead of 12V but the tone is still the same. What output current is the T-Rex?

[quote name='jimbartlett' timestamp='1494092533' post='3293236'] Hi Dave. A wet/dry blend, standard Boss power supply (negative centre, 9v) and smaller would be great. A D.I. would be welcome but not sure a headphone option or Line In would be necessary. Some people may totally disagree with that though. [/quote] Thanks, useful info.

[quote name='danbowskill' timestamp='1494091971' post='3293233'] Yeah man definitely a 9v version i could daisy chain (internal charge pump?) i had a early vt1 , but now having a small pedaltrain board i'd love all pedals to be run off the same supply. Also simplicity isn't such a bad thing either :-) the likes of all the features on the new GK pre pedal just puts me off the thing [/quote] Having valves in there does limit what power supply I can use. There is already a charge pump in there that takes the 9-12V and generates the higher plate voltage. The 9-12V runs the valve heaters which is what takes all the current. The new versions will run off a 9v daisy chain an long as there is enough current.