Vintage valve heads and huge vintage cabs

[Bill Fitzmaurice]

[quote name='Mr. Foxen' post='310797' date='Oct 20 2008, 04:15 PM']Occurred to me that the speaker is effectively in a very small enclosure of its own.[/quote]It's for reactance annulling.
[quote]Exactly, I was making the point that just because something is old-fashioned or lo-fi doesn't make it no good.[/quote]No argument, my point is that this old behemoth can be beat. and seriously so, by a modern cab literally half its size and weight. Restoring it is like restoring a 50 year old luxury car that gets 10 miles to the gallon. There is value in so doing, but from the standpoint of practicality you wouldn't want to use it for your primary mode of transport.

[Mr. Foxen]

[quote name='Bill Fitzmaurice' post='310844' date='Oct 20 2008, 10:20 PM']It's for reactance annulling.[/quote]

Just read this article (in a 1920s raddio announcer voice) on that: [url="http://forums.klipsch.com/forums/storage/3/869228/Reactance_Annulling_by_Plach_and_Williams.pdf"]Reactance anulling[/url]

That means it even out the responce right? This stuff is heading to more complicated than I need to know, but I'm an enquiring sort of guy. All back together now. My Dad restores classic cars, I can see the paralells, luckily, there is less legislation governing speakers and how they are made.

[Thunderhead]

That's actually a very good driver, and probably not original to the cab either - I would have expected some sort of British speaker like a Celestion, Fane or Goodmans given the age and origin of the cab. Is there a power rating marked on it? (I can't see in the pic.)

Are you certain that it's blown? Or could it be reacting badly to the enclosure? Is there any - or enough - wadding in the space inside the triangular box? There seems to be the remains of some on the magnet fins.

[Mr. Foxen]

Don't think its blown, just figured (on another's advice) that modern driver will like low A much better, it did seem to be farting out some, but I suspect it would be very loud given some distance at that point. Ain't pushed it again since I took everything apart and tightened it all. Some of the bolts were kinda loose. Loads of wadding in there. is there some property like you need to be half the wavelenngth away fromthe cab for the sound to resolve properly? Its definitely louder further away. Didn't spot a power rating, the cab says 150 watt (the head actually says 130RMS, guess he read wrong thing when listing), but that doesn't relate if driver is replacement.

[skankdelvar]

Why not post a soundclip when you're done - nice to hear it...

[Mr. Foxen]

[quote name='skankdelvar' post='312287' date='Oct 22 2008, 04:43 PM']Why not post a soundclip when you're done - nice to hear it...[/quote]

Rocked it as is last night in practice, sounded great. Paired it with a Marshall JCM600 into a 4x10 for some top (make up for single guitarist). Filled the place with low end.

[alexclaber]

[quote name='Mr. Foxen' post='312292' date='Oct 22 2008, 04:47 PM']Rocked it as is last night in practice, sounded great. Paired it with a Marshall JCM600 into a 4x10 for some top (make up for single guitarist). Filled the place with low end.[/quote]

Excellent! If it ain't broke...

Alex

[Thunderhead]

[quote name='Mr. Foxen' post='312292' date='Oct 22 2008, 04:47 PM']Paired it with a Marshall JCM600 into a 4x10 for some top (make up for single guitarist). Filled the place with low end.[/quote]You're lucky that didn't fill the place with a nasty burning smell...

I would seriously NOT recommend this for bass given the volume I'm sure you're playing at .


If you want a decent Marshall guitar amp for top-end bass crunch, you'd be better with a JMP or JCM800 single-channel MV amp, they have less of a tendency to double as a smoke machine . (And they sound far better too.)

Edited October 22, 2008 by Thunderhead

[Mr. Foxen]

[quote name='Thunderhead' post='312401' date='Oct 22 2008, 07:19 PM']You're lucky that didn't fill the place with a nasty burning smell...

I would seriously NOT recommend this for bass given the volume I'm sure you're playing at .


If you want a decent Marshall guitar amp for top-end bass crunch, you'd be better with a JMP or JCM800 single-channel MV amp, they have less of a tendency to double as a smoke machine . (And they sound far better too.)[/quote]

Wheres that issue come from? Didn't crank it that much, gain channel sounded aids, so ran it clean. Tried a vintage modern (if thats what you meant by MV) didn't think much of it tbh. Really only used the JCM600 cause I have it about. Have a 70s carlsbro 100w head thats more the part, but its also got the dodge power lead and isn't really mine to change.

[Thunderhead]

[quote name='Mr. Foxen' post='312430' date='Oct 22 2008, 07:42 PM']Wheres that issue come from?[/quote]They have problems with blowing output transformers, overheating, frying power valves, screen resistors desoldering themselves, and a few other things. Not one of Marshall's better designs...

[quote]Tried a vintage modern (if thats what you meant by MV) didn't think much of it tbh.[/quote]No! A Vintage Modern is a totally different amp, and I didn't think much of the one I tried either (for guitar - but I doubt it would be any better for bass because it sounded very thin).

The JMP or JCM800 Master Volume model (model 2204 50W or model 2203 100W) is a much simpler, single channel amp with no switching, reverb or any other features other than High and Low (which bypasses one gain stage to give a cleaner sound) inputs, and Preamp Volume/Master Volume/Treble/Middle/Bass/Presence controls. They're among the most bombproof amps ever made by any company (earlier models with iffy voltage and impedance selectors aside), sound absolutely great and even the 50W version will blow a "60W" JCM600 into the middle of the next street . The 100W 2203 is one of the loudest and most dynamic valve amps ever made. (The 100W rating is extremely conservative too, most measure in the 140W region even clean and will easily top 200W fully distorted.) I actually think - guitar purists will no doubt disagree! - that the 2203 is the best-sounding Marshall ever, early JMP ones especially.

Marshall have reissued the 2203 now, but I wouldn't really bother when you can get originals for much less, even including a service.

Edited October 22, 2008 by Thunderhead

[joegarcia]

[quote name='Mr. Foxen' post='312430' date='Oct 22 2008, 07:42 PM']Wheres that issue come from? Didn't crank it that much, gain channel sounded aids, so ran it clean. Tried a vintage modern (if thats what you meant by MV) didn't think much of it tbh. Really only used the JCM600 cause I have it about. Have a 70s carlsbro 100w head thats more the part, but its also got the dodge power lead and isn't really mine to change.[/quote]

I really think you're worrying too much about the bulgin thing. As long as you unplug it from the wall before the amp and make sure you have a spare, whats the issue?

[Thunderhead]

[quote name='joegarcia' post='312674' date='Oct 23 2008, 01:24 AM']I really think you're worrying too much about the bulgin thing. As long as you unplug it from the wall before the amp and make sure you have a spare, whats the issue?[/quote]That they are unsafe, especially the 'inline' ones - it's possible for the cable to get pulled and partially disconnect the wires inside, maybe leaving you with no earth... and worse, the earth wire floating around loose where it could come into contact with either of the other pins - the design was always inadequate regarding cable retention.

And that they are illegal, even the better right-angle ones. There are venues where this could cause a problem if they get officious about health and safety requirements (seriously).

They are an absolutely terrible connector, always were, and should be consigned to history. It's a pity there is no way of making a IEC socket fit the same hole without cutting a small amount of the chassis away, but it's a small price to pay really. It would be better if someone made a round IEC socket that matched the outline of the Bulgin... but they don't.

[joegarcia]

Yea I know all that but I'm sure I read it's legal to have them on vintage gear that would lose it's value if modified. No?
I'm just saying that personally, if it was a choice between using a good amp with a bulgin or a bad amp with an IEC I'd choose the good amp.

[Thunderhead]

[quote name='joegarcia' post='312874' date='Oct 23 2008, 12:04 PM']Yea I know all that but I'm sure I read it's legal to have them on vintage gear that would lose it's value if modified. No?[/quote]No. Electrical safety regulations do not pay any regard to the 'value' of an item.

There's nothing to stop you using one personally, but you could possibly be in trouble if you sell it, and an accident then happened to the buyer. Technically these connectors are not legal for use with any voltage over 50V due to failing on several counts - cable retention, being able to be dismantled without tools (both for the inline type), and the socket holes being too large (AKA 'toddler's finger test', which applies to both types). Shops in particular need to be careful about selling amps with them, since as professionals in the trade they could reasonably be expected to know the rules and risks, and could possibly be held legally accountable. I don't know if it's ever happened though.

[quote]I'm just saying that personally, if it was a choice between using a good amp with a bulgin or a bad amp with an IEC I'd choose the good amp.[/quote]Of course, so would I... and then fit it with an IEC .

I'm not saying I would [i]always[/i] fit one - there are some vintage amps which are original enough that it's not really 'right' to do so, and mostly these will not be in professional use anywhere it could cause a problem. But any amp which you can expect to use at a gig needs a proper modern power connector, in my opinion - for safety, reliability and easy replacement if you break or lose it. I don't really understand the logic of keeping a crappy old part in use for the sake of originality, when you need to change other parts of the amp occasionally when they fail anyway.

It is a real pity there isn't a proper 'in keeping' IEC socket available which would preserve the look of the amp without being obvious that a new connector has been fitted across the hole from the old one (it's difficult even to close off the gaps without it looking like a bodge in some way) - I'm actually more bothered by that than the idea of filing out a couple of corners from the chassis hole.

[joegarcia]

[quote name='Thunderhead' post='313170' date='Oct 23 2008, 06:11 PM']Of course, so would I... and then fit it with an IEC .[/quote]

Yes, but in this case he can't modify it as it isn't his so it's not getting used at all.