Jump to content
Why become a member? ×

Bassman Amp


Musicman69
 Share

Recommended Posts

[quote name='Musicman69' post='754115' date='Feb 22 2010, 12:46 PM']Hi Folks,

This is my old Bassman head, I bought it in 1980 for 50 punts (with cab)
Just thought Id put up pics and maybe someone here might know its age. Looks very '60s to me.
Any info appreciated.. thanks.

John

[attachment=43321:Bassman1.gif]

[attachment=43324:Bassman2.gif][/quote]
Take a look here:
[url="http://www.ampwares.com/"]http://www.ampwares.com/[/url]

It appears to be a 61-62, and it might be worth about 100 times what you paid for it.

Link to comment
Share on other sites

Assuming the logo and handle haven't been replaced with later variants, that looks like a 1964 6G6-A / B. Very desirable. If you're using it, make sure the ground lift switch has been isolated.

And if you've got a matching cab, you're sitting on a little gold mine. Not that money's everything - that's just a lovely old amp.

Swoon. :wub:

Edited by skankdelvar
Link to comment
Share on other sites

[quote name='Musicman69' post='754280' date='Feb 22 2010, 07:42 PM']Dont think Ive ever touched that switch as I dont know what it does!
Why is it there.. Different power sources maybe?[/quote]
A ground lift disengages the amps electrical earth. Sounds dangerous. It is. Why do it?

[quote]if you have two pieces of equipment in a sound system connected to earth through their respective mains cables, it can cause an 'earth loop', sometimes called a 'ground loop' or 'hum loop'. This in turn causes a 50 Hz or 60 Hz hum[/quote]
So, if you're running two connected mains items, you disconnect one item's - (which in this case would be your amp) - electrical earth and it stops the hum. Basically, it's what they did in the US years ago to make it convenient. Total no-no these days in the UK.

See, it's fine if the [i]other[/i] mains-powered item is earthed. But if you haven't got that other earthed item, your amp may eventually earth through you, rendering you dead as arseholes. Taking the ground-lift switch out of the circuit will enhance your safety no end. And it's a 2 minute job for an amp tech. Had it done on a number of occasions.

Now it may be the case that someone already had this ground lift switch sorted before you bought the amp. But it's worth getting it checked before you fire the amp up again.

Edited by skankdelvar
Link to comment
Share on other sites

Oh right! I hear you loud and clear...

Never had any hum problems with it thankfully. I had some work done on it a few years ago so the switch might have been by-passed but I cant be certain.
Ill get it checked out.

Many thanks for that info Skankdelvar

Edited by Musicman69
Link to comment
Share on other sites

[quote name='skankdelvar' post='754343' date='Feb 22 2010, 03:39 PM']A ground lift disengages the amps electrical earth.[/quote]
Not quite. Amps of that era had no direct chassis connection to ground, as they used a two-wire connection to the mains. To provide noise filtering they connected the chassis to the ground wire via a capacitor. The problem lay in knowing which of the two wires was connected to hot and which was ground, as the plugs and outlets were not polarized. The ground switch toggled the connection through the cap from one wire to the other. When you powered the amp up you listened for noise and switched the ground switch to the quieter position. Of course when in the wrong position the chassis was connected to the hot wire, but since it was via a cap in the .1uF range it didn't get a full 60 Hz signal, just the higher harmonics. If you touched the chassis or anything connected to it, like your bass, and something that was grounded, like a mic, you'd get a benign but unmistakable reminder of why one should not play an instrument whilst bathing.
The ground lift switch on modern gear lifts the ground from the signal direct out, not the chassis to mains ground.
[quote]I had some work done on it a few years ago so the switch might have been by-passed but I cant be certain.
Ill get it checked out[/quote]. If converted to UK power it should have a 3 wire connection, grounding the chassis and eliminating the ground switch. Unfortunately that would lop a few hundred quid off its value to a collector.

Link to comment
Share on other sites

[quote name='Bill Fitzmaurice' post='754382' date='Feb 22 2010, 09:08 PM']Not quite. Amps of that era had no direct chassis connection to ground, as they used a two-wire connection to the mains. To provide noise filtering they connected the chassis to the ground wire via a capacitor. The problem lay in knowing which of the two wires was connected to hot and which was ground, as the plugs and outlets were not polarized. The ground switch toggled the connection through the cap from one wire to the other. When you powered the amp up you listened for noise and switched the ground switch to the quieter position. Of course when in the wrong position the chassis was connected to the hot wire, but since it was via a cap in the .1uF range it didn't get a full 60 Hz signal, just the higher harmonics. If you touched the chassis or anything connected to it, like your bass, and something that was grounded, like a mic, you'd get a benign but unmistakable reminder of why one should not play an instrument whilst bathing.
The ground lift switch on modern gear lifts the ground from the signal direct out, not the chassis to mains ground.
If converted to UK power it should have a 3 wire connection, grounding the chassis and eliminating the ground switch. Unfortunately that would lop a few hundred quid off its value to a collector.[/quote]

I assume you would nevertheless agree that having it checked is a prudent course of action.

Edited by skankdelvar
Link to comment
Share on other sites

Useful info here, if you haven't already found it: [url="http://www.ampwares.com/amp.asp?id=26"]http://www.ampwares.com/amp.asp?id=26[/url]

From the specs, sounds like a 1964. The year after JFK died, the year of Beatlemania in the US and five years before Neil Armstrong set foot on the moon. If you show it to guitarists of a certain age, make sure they've got a change of strides to hand, cos they'll poop themselves.

Google '6G6B bassman' and you'll find loads of info. Really glad you've got such a nice amp to hand - almost as good as finding it in an attic :). Now all you've got to do is get yourself a matching 2x12 chambered cab and you're laughing.

Edited by skankdelvar
Link to comment
Share on other sites

[quote name='skankdelvar' post='755340' date='Feb 23 2010, 07:18 PM']Useful info here, if you haven't already found it: [url="http://www.ampwares.com/amp.asp?id=26"]http://www.ampwares.com/amp.asp?id=26[/url]

From the specs, sounds like a 1964. The year after JFK died, the year of Beatlemania in the US and five years before Neil Armstrong set foot on the moon. If you show it to guitarists of a certain age, make sure they've got a change of strides to hand, cos they'll poop themselves.

Google '6G6B' bassman and you'll find loads of info. Really glad you've got such a nice amp to hand - almost as good as finding it in an attic :). Now all you've got to do is get yourself a matching 2x12 chambered cab and you're laughing.[/quote]

Yeah I had a look at Ampwares.com, seems like its a '64 alright. I wasnt even born then.
Tried to track down the cab, a mate bought it from me way back then. Called him up but he's no idea where it is, probably got dumped somewhere. Ouch!

So.. it has laxative powers also? :rolleyes: :lol:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...