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[Ampeg B15R] Following Jess Oliver's advice...

#101
[
Bass 45 said:
I just looked at my B15R -- the void should appear near the text indicating your intended selection - NOT the block portion of the switch.

Here is mine pictured - set for 6L6 tubes and 8 ohm speaker:

View attachment 2806816
Click to expand...

I have been using Ampegs for many years and on any other Ampeg you would have that in the 4 ohm and EL-34 position. My B-15S has a switch that looks just like yours but has 3 positions, 2,4 and 8 ohms, and the "block" portion is how you set it (and every other Ampeg I've ever seen), how do i know that? Because the "void" position covers two impedances while the "block" only one.
 
#102
beans-on-toast said:
Are you sure about the switch settings Rich?

Here is the manual: http://www.ampeg.com/pdf/B-15R.PDF.

Cc: @Bass 45
Click to expand...

I sure hope he's right because that is my understanding and how I run mine, also. But, I don't remember how I came by that understanding. I *think* it's simply because mine came with 6L6 tubes and the tube bias switch was set that way (with the "hole" on the 6L6 side). But, I bought mine used, so it certainly *could* have been set incorrectly.

Looking at the manual, it is not conclusive, by any means. But, it LOOKS like Rich's/my understanding is correct.

I stick the tip of an instrument cable in the "hole" and position it to the setting I want. If the cable plug or slotted screwdriver were lined up with the setting I DON'T want, that would be counter-intuitive, to me.

I wish I had time to open things up and check it, as beans described, but I don't see that happening any time soon....

I put EL34 tubes in mine a while back (and flipped the bias switch) and have gigged it standalone and with a B-15E extension cab (flipping the impedance switch as appropriate) a number of times. Always sounds great. Hasn't blown up....
 
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#103
StuartV said:
I sure hope he's right because that is my understanding and how I run mine, also. But, I don't remember how I came by that understanding. I *think* it's simply because mine came with 6L6 tubes and the tube bias switch was set that way (with the "hole" on the 6L6 side). But, I bought mine used, so it certainly *could* have been set incorrectly.

Looking at the manual, it is not conclusive, by any means. But, it LOOKS like Rich's/my understanding is correct.

I stick the tip of an instrument cable in the "hole" and position it to the setting I want. If the cable plug or slotted screwdriver were lined up with the setting I DON'T want, that would be counter-intuitive, to me.

I wish I had time to open things up and check it, as beans described, but I don't see that happening any time soon....

I put EL34 tubes in mine a while back (and flipped the bias switch) and have gigged it standalone and with a B-15E extension cab (flipping the impedance switch as appropriate) a number of times. Always sounds great. Hasn't blown up....
Click to expand...

This is really good that the question was asked, the manual isn't clear, that's for sure.

The only way to know, without documentation from Ampeg, is to check the circuit and check that the connector is not installed or assembled backwards. If it helps, looking at the schematic segments, you can see the switches below. The two parallel black lines are over the setting of the switch. The actuator block is normally over the black lines. In these diagrams EL34 and 4 ohms are selected.


Terminals 1 and 2 are shorted. Terminals 4 and 5 are shorted.
B-15R bias.jpg



Terminals 1 and 2 are shorted. Terminals 4 and 5 are shorted.
B-15R impedance.jpg


I've increased the contrast in Rich's image to show the switch settings.

B-15R switches.jpg
 
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#104
the block isn't the inducator, the dimple hole is. I no longer have mine (B15R/B15E), but I had bought it at Bass NW, the dimple dragged toward the direction of the text is what the setting is: in that picture would be 6L6 and 8 ohm.

IOW, the block is on both sides of that dimple.
 
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#108
Thank you for your input David. @beans-on-toast

Owner's manual aside, the switch actually is very intuitive in person - maybe I just have not found the best way to explain it. The switch slides all the way to the left for four ohms and all the way to the right for 8 ohms. It slides all the way to the right for 6L6 tubes and all the way to the left for EL34 tubes - these actions correspond to the lettering's placement on the chassis.

These switches do not resemble the three way switch found on 1970's V4's and B15S's.

On a related note - I've got about 14 years of virtual trouble free use with my B15R ;)
 
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#109
marsbel said:
This type of switch is meant to be actuated by a flat blade screwdriver. Insert the blade in the gap, and move it to your desired position.

And since this thread has been ressurected:
Could someone give me the dimensions of the transformer cans? I have an empty B-15R chassis that I'd like to built up.
The transformers/cans are unobtainable, so I'll have to make them myself.
Click to expand...

The cans measure: H - 5 3/8 W - 4 1/4 D - 5
 
#110
Bass 45 said:
Thank you for your input David. @beans-on-toast

Owner's manual aside, the switch actually is very intuitive in person - maybe I just have not found the best way to explain it. The switch slides all the way to the left for four ohms and all the way to the right for 8 ohms. It slides all the way to the right for 6L6 tubes and all the way to the left for EL34 tubes - these actions correspond to the lettering's placement on the chassis.

These switches do not resemble the three way switch found on 1970's V4's and B15S's.

On a related note - I've got about 14 years of virtual trouble free use with my B15R ;)
Click to expand...


That makes more sense to me when you describe it in terms slide left for EL34 and slide right for 6L6. It was my impression that you were originally saying the opposite.

I assume that’s when standing behind the amp, not leaning over it from the front where left and right are reversed. I get easily confused. :laugh:
 
#111
beans-on-toast said:
That makes more sense to me when you describe it in terms slide left for EL34 and slide right for 6L6. It was my impression that you were originally saying the opposite.

I assume that’s when standing behind the amp, not leaning over it from the front where left and right are reversed. I get easily confused. :laugh:
Click to expand...

I think in my initial reply, I was trying to address the question using Punchclock's description.

Yes - Right/Left when facing the back of the amp ;)

Your recent posts only further prove your high expertise and willingness to help others on TB - in this case, I just have the benefit of owning the amp - and I never read the manual (which I hear is confusing;)) !
 
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#112
beans-on-toast said:
That makes more sense to me when you describe it in terms slide left for EL34 and slide right for 6L6. It was my impression that you were originally saying the opposite.

I assume that’s when standing behind the amp, not leaning over it from the front where left and right are reversed. I get easily confused. :laugh:
Click to expand...

LOL If you're using EL34s, slide the switch TOWARDS where it says EL34. Etc.. No matter which side of the amp you're standing on. :D
 
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#117
BassmanPaul said:
I disagree. Both switches are set to the left and that’s EL34 and 4Ω. Any thing else would be absurd!
Click to expand...

Of course it is not conclusive, but myself and 2 other B-15R owners (or former owners) in this thread all understand the switch position shown to mean 6L6 and 8 ohm.

When I set those switches on mine, the only practical way to move the switch is to stick something in the "hole". I use the tip of an instrument cable plug. At which point, I push the switch towards the setting I want. So, the "hole" ends up on the side of the "selected" setting.

However, if you know something different about operation of a B-15R, I am surely all ears.

If it worked the way you suggest, I would think I would need to be able to slide the raised portion of the switch towards the desired setting. But, you can't. The switch doesn't work that way. You would have to slide the raised portion away from the desired setting, to reveal a different raised portion. Which would be absurd! ;-)
 
#118
BassmanPaul. I think that if you had the amp above in front of you, you would find the it is intuitive in operation that (using a small screwdriver), you would be able to move the switch slider to select settings. I think you are mis-interpreting the shown settings by thinking of a switch that has a protruding part sticking out operated by a finger, that on these switches is a recess, operated by a tool. I am sure you have encountered this style of switch before, and your eyes are fooling your memory and experience momentarily.
 
#120
Sorry folks, for resurrecting this ancient "necro" thread, but there's so much great discussion by lovers/owners of these amps, I figured this as an appropriate continuation. Can anyone provide the outer dimensions of the B-15R? I can't find them anywhere. I'm looking to buy one of these amps and am planning to try something kinda bizarre! I'm contemplating building a new, fliptop, Portaflex style box, configured as half of an 810, with two separate 2x10 chambers. It would seem that with the 100+ watts of the B-15R pushing it, it would be a crushing little (though likely pretty heavy) small club rig. Before I start making any sawdust, I need to get the amp and I will test my theory by running the amp through half of an existing 810E.

It seems that the 4x10s would clear up that bottom end that @Triboost was not fond of and really tighten up the low mid punch and clarity?

Am I On Drugs?
Gene
 
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