DHA VT5-400 Yes indeed a custom Bass amp. Intial Review / Pics added

[nedsbeds]

it's not a build thread without pics

[DHA]

[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

[BigRedX]

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.

[Merton]

[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]
+1

[DHA]

[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

Edited September 27, 2007 by DHA

[Alpha-Dave]

And all those bits fit in that little pedal, cripes! it's a tardis!

[neilb]

Dave

Cant see the muffplate in your picture. I see you are going for the cocktruss array idea....good old boy!

[DHA]

[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

[DHA]

[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

[Alpha-Dave]

[quote name='DHA' post='66379' date='Sep 27 2007, 12:32 PM']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.[/quote]

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?

[DHA]

[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

[Alpha-Dave]

Ah, I see. The only post I've seen before are the ones that are pre-cut to size.

[neilb]

[quote name='DHA' post='66387' date='Sep 27 2007, 12:46 PM']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]


Knob trimming is an important stage of the build, isnt it Dave?

[Sugden]

Hey dave thanks for the pics looks like its coming along swiftly. Going to be a nice full box by the end of things.

[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

[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]

Hi Sug,

The 400W amp just arrived, so that's all the bits here now.

I see a weekend of drilling and metal bashing coming on.

dave

[paul, the]

[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]

[Rich]

Watching this with keen interest.

[quote name='DHA' post='66370' date='Sep 27 2007, 12:18 PM']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]
Perfect. All it needs is a rackmount kit.

[DHA]

[quote name='Rich' post='67547' date='Sep 30 2007, 12:23 AM']Watching this with keen interest.
Perfect. All it needs is a rackmount kit. [/quote]

Build update -

note the EL90 power valve next to the output transformer. There is only one pre-amp valve fitted on this pic, 3 more to add.

The 400W UcD module is on the back panel, the big black round thing is the transformer for it.

[attachment=2541:PICT0035.JPG]

[neilb]

You have a lovely pair of smoothing caps there Dave........................

[Sugden]

Thats a pretty serious looking transformer.

Looks like some serious hours gone in there. If i knew what I was looking at Im sure Id be saying fantastic work. Theres some lovely looking 3 teir circuit boards.

[DHA]

[quote name='Sugden' post='67692' date='Sep 30 2007, 03:23 PM']Thats a pretty serious looking transformer.

Looks like some serious hours gone in there. If i knew what I was looking at Im sure Id be saying fantastic work. Theres some lovely looking 3 teir circuit boards.[/quote]

I have to add the components to the 3 teir circuit boards, but they are the compressor, blender, pre-amp and driver.

[DHA]

Latest.....

[attachment=2884:PICT0007.JPG]

The paint job is a custom one as requested by Sug.

The final production models will be silkscreened and have an input and output LED VU meter, all the other features will be the same. There will be a blue backlight showing one of the five valves via the vents. The footswitch controls the compressor and Fx blender off and on as well as the Tuner mute.

The colour of the LEDs matches the knobs which are different for different functions, i.e. pre-amp is red, blender yellow, etc.

Two of these are still available at the lower cost to BC members.

Dave

[wotnwhy]

thats looking terrific. bet it sounds ok too

[BigRedX]

Dave - will you have one of these amps with you a Music Live?

I'd very much like to try one out.