Small lightweight ALL VALVE amplifiers?

[hairychris]

[quote name='solo4652' timestamp='1423737021' post='2688369']
I'm following this thread out of idle curiosity. I have absolutely no idea how valves, transformers and such stuff work. Just maybe, that might enable someone as ignorant as me to suggest something outwardly daft that could possibly work. Top-of-head musings;

1. Are some valves physically smaller than others?

2. Do some valves produce less heat than others?

3. Do you [i]have[/i] to have fan cooling, with the associated fan, motor, thermostat, wires and noise? How about valve dampers - would they eliminate, or at least reduce the size of fans+gubbins? My home radiators have loads of fins behind them to increase surface area for heat release.

[url="http://vintageaudiovalves.com/eat-tubes"]http://vintageaudiov...s.com/eat-tubes[/url] and [url="http://www.guildfordaudio.co.uk/store/category.php?category=Valve%20Dampers&section=Accessories&cattitle=Accessories&page=category"]http://www.guildford...s&page=category[/url]

4. Do the valves [i]have[/i] to be next to each other? If they were separated inside the box, would that help prevent localised heat build-up? Indeed, do the valves have to be inside the box at all? In the best tradition of home decorating, if you can't hide something, make a feature of it. Put the valves on full display with just a minimalist (heat-resistant plastic?) cage/cover for protection? Arab tents use the shape of the funnel-roof to encourage air exhaust and thus cooling.

5. Perhaps the cover could be circular with the airflow sent round a spiral (Dyson vacuum cleaner) to increase the airflow.

So; small, cool-running valves placed on their side with heat-dissipation fins/jackets (maybe with a smaller fan system with some sort of venturi-effect airflow accelerator?), placed apart, and placed outside of the main box under some sort of circular minimalist plastic cover that doubles as a clever air-exhaust chimney.

I'm sorry. I'll shut up now.
[/quote]

Briefly

1) Yes, but they tend to be lower power. You'll need more of them for the equivalent power handling, and that's without tonal implications.

2) The smaller preamp ones, basically. All valves have a heating element and run hot, so there is no such thing as a cool valve. Plus the output transformer as even solid-state amps run hot. Heat will always be a problem with the voltages that are used by amps.

The currently-being-developed solid-state "valves" look potentially interesting but 1) it's future tech 2) no idea how they sound 3) unsure if they will be able to handle output stage functionality and 4) there are other things in the amp (transformer, especially) that'll still be generating heat.

3) No. Many amp heads don't have a fan, but they are relatively open to the outside world. Cramming anything like an output transformer and output tubes in a confined space/rack and you have to ventilate. Even those normal amp heads can misbehave in a hot venue so may need external fans for cooling.

And, fwiw, those heatsinks only pull heat from the tube and try to dump it in the surrounding air. This air needs to be circulated so it's not actually removing any heat from hte system as a whole.

4) Not in theory. However for efficiency keeping the related parts next to each other will help. If you don't you would need a lot of break-off boards and spaghetti wiring which would be expensive to build + repair and potentially prone to failure.

5) You'll still need fans for the airflow, and on top of this you'd need to design/prototype/manufacture this item. Way cheaper to just stick a fan in there, or have the valves open to air like your standard guitar head or audiophile hifi amp.

To handle 100w you need a pretty large transformer and 2 large (KT88) or 4 smaller (6L6/EL34) valves, plus preamp. This gives you a certain minimum size that you can work with. Solid-state can go much smaller, especially Class D power amps as they are way more efficient than tubes.

Could amps be built smaller? Possibly, yes, but we start to run into other issues as it'll need to be built sturdily enough to survive studios/live, and the 100+w transformers are *always* going to be big & very heavy.

[solo4652]

OK - thanks for your patient and informative reply. Looks like fans will be needed then, no matter how clever the box architecture is. Back to the drawing board.

Edited February 14, 2015 by solo4652

[JapanAxe]

[quote name='MoonBassAlpha' timestamp='1423748435' post='2688562']
... if you read what Stewart Ward (Session amps) writes about valve sounds and tone, it turns out you don't really need valves at all, just better informed transistor design...
[/quote]

This will be the same Stewart Ward that builds and sells transistor-powered Session Amps? He's done pretty well with them, but clearly he does have a vested interest!

BTW I am not knocking Session Amps - I used to own one of the guitar combos, and it was very good for a solid state amp.

[JapanAxe]

[quote name='obbm' timestamp='1423694428' post='2688127']
Putting the overall height thing to one side for a moment the one thing that bugs me is the width of many valve amps. Many cabs are now even narrower than a 19-inch rack case so most valve amps overhang both sides. Very ugly.
[/quote]

Yes, I am always on the lookout for an all-valve head no more than 19in wide - the width of my Barefaced cabs! The Selmer T'n'B is barely wider (mine is only 50W), and those Trace valve heads are also about the right size but with only a graphic for tone control.

[Roland Rock]

My Red Iron 100w amp sits nicely on top of my Super Twin cab with room to spare on each side. It has a manageable weight. No way are those transformers or KT88s are going to fit in a 2U rack though

[Dood]

I wonder how this would get on for bass guitar? http://www.carvinworld.com/products/TS100

[obbm]

[quote name='dood' timestamp='1423913956' post='2690285']
I wonder how this would get on for bass guitar? [url="http://www.carvinworld.com/products/TS100"]http://www.carvinwor.../products/TS100[/url]
[/quote]

Looks interesting but no details of frequency response. Also bridged runs into 8-ohms only so could be problem with single 4-ohm cabs.

It's 26lbs without a pre-amp or a rack case against the Prodigy's 29lb. all up.

[discreet]

[quote name='JapanAxe' timestamp='1423907015' post='2690188']
Yes, I am always on the lookout for an all-valve head no more than 19in wide - the width of my Barefaced cabs! The Selmer T'n'B is barely wider (mine is only 50W), and those Trace valve heads are also about the right size but with only a graphic for tone control.
[/quote]

You need a Burman MPA and SL100 Powerpak!
[url="http://basschat.co.uk/topic/227325-nad-burman-mpa-sl100-powerpak/"]http://basschat.co.u...sl100-powerpak/[/url]

Weight in thread is inaccurate - it's only 35kg in total.

Edited February 14, 2015 by discreet

[Subthumper]

I had a measure up of transformers and I'm gonna have a go at this. I think it's pretty feasible to be able to fit into a box 18" wide, 12" deep and 4.5" high. With the width and depth it may possible to reduce it a bit more although I'm stuck with the height due to the transformers. The amp spec will be kept straightforward, gain, bass ,mid, treble and master volume, bass boost/fat switch and mid shift, 3x ecc83, 4x6l6.fan cooled.
If anyone can think of any other features to shoe horn into it or what type of handles to use please do say.

Edited February 14, 2015 by Subthumper

[disssa]

The Aguilar DB 359 ist a rackmountable all valve amp: [url="http://www.musiker-board.de/threads/amp-aguilar-db359-r%C3%B6hrenamp.483004/"]Klick[/url]





Good sounding "one-tone"-wonder with a depth of 45 cm and a weight of 22 kg...

[JapanAxe]

[quote name='dood' timestamp='1423913956' post='2690285']
I wonder how this would get on for bass guitar? [url="http://www.carvinworld.com/products/TS100"]http://www.carvinwor.../products/TS100[/url]
[/quote]

Ooh! (Excitement at thought of combining with an SVP...)


[quote name='discreet' timestamp='1423915771' post='2690309']
You need a Burman MPA and SL100 Powerpak!
[url="http://basschat.co.uk/topic/227325-nad-burman-mpa-sl100-powerpak/"]http://basschat.co.u...sl100-powerpak/[/url]

Weight in thread is inaccurate - it's only 35kg in total.
[/quote]

Aah! (Anticipation of discs being squashed to pulp and vertebrae grinding together as I drag this lot around..)

[JapanAxe]

[quote name='disssa' timestamp='1423951278' post='2690896']
The Aguilar DB 359 ist a rackmountable all valve amp: [url="http://www.musiker-board.de/threads/amp-aguilar-db359-r%C3%B6hrenamp.483004/"]Klick[/url]





Good sounding "one-tone"-wonder with a depth of 45 cm and a weight of 22 kg...
[/quote]

Depth of 45cm? That will overhang the back of my Barefaced cabs by 10cm!

[Dad3353]

[quote name='JapanAxe' timestamp='1423951708' post='2690904']
Depth of 45cm? That will overhang the back of my Barefaced cabs by 10cm!
[/quote]

... and..?

[JapanAxe]

[quote name='Dad3353' timestamp='1423951891' post='2690908']
... and..?
[/quote]

Well it's not as bad as side overhang (aargh!) but it offends my sense of neatness. And probably the feet won't be resting on the cab. This is the sort of thing that keeps me awake at night...

[Dad3353]

[quote name='JapanAxe' timestamp='1423952372' post='2690924']
Well it's not as bad as side overhang (aargh!) but it offends my sense of neatness. And probably the feet won't be resting on the cab. This is the sort of thing that keeps me awake at night...
[/quote]

The solution would be to only by combos, maybe..?
How do you arrange your packets in the kitchen cupboard..? By height..? By width..? By colour..? When you sharpen a pencil, does it worry you that it's now shorter than the others, so you have to sharpen those, too..? So many niggles in life, eh..?

[JapanAxe]

[quote name='Dad3353' timestamp='1423952626' post='2690927']
The solution would be to only by combos, maybe..?
How do you arrange your packets in the kitchen cupboard..? By height..? By width..? By colour..? When you sharpen a pencil, does it worry you that it's now shorter than the others, so you have to sharpen those, too..? So many niggles in life, eh..?
[/quote]
No more combos for me - I like mixing and matching.

However I can confirm that all my CDs are in alphabetical order by artist. There are exceptions though, e.g. Tin Machine is filed under David Bowie.

[Dad3353]

[quote name='JapanAxe' timestamp='1423953308' post='2690934']
No more combos for me - I like mixing and matching.

However I can confirm that all my CDs are in alphabetical order by artist. There are exceptions though, e.g. Tin Machine is filed under David Bowie.
[/quote]

I'll bet you just love jigsaw puzzles..!

[obbm]

[quote name='disssa' timestamp='1423951278' post='2690896']
The Aguilar DB 359 ist a rackmountable all valve amp: [url="http://www.musiker-board.de/threads/amp-aguilar-db359-r%C3%B6hrenamp.483004/"]Klick[/url]





Good sounding "one-tone"-wonder with a depth of 45 cm and a weight of 22 kg...
[/quote]

Alas 19-inch rack mount plus rack case = overhang either side of any 12-inch Berg cabinet = misery.

[Dad3353]

Another good reason for using HH cabs..!

Edited February 14, 2015 by Dad3353

[obbm]

[quote name='Dad3353' timestamp='1423954175' post='2690950']
Another good reason for using HH cabs..!


[/quote]

Nah. Never get it in the Dog and Duck.

[Dad3353]

[quote name='obbm' timestamp='1423954995' post='2690962']
Nah. Never get it in the Dog and Duck.
[/quote]

...nevertheless, that's all we ever play..!

[Dood]

That's a big beasty!!!

[fretmeister]

Buy a Prodigy. It's an awesome amp.

[Dazed]

Has anyone come across a Bassett Hound before?

http://www.alessandro-products.com/amp-basset.html






Can I have a gold chassis version please

[Subthumper]

That style of thing is a lot easier to do than squeezing things into a 2U rack. It uses standard transformers rather than custom made ones. And no fan. Should I make one? If so what do folks want to see feature wise?