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What is this tube head??


megadan

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I was under the impression that Peavey only made two all tube heads: the Alphabass and the Classic 400.

 

 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330025326870&ssPageName=ADME:B:WNA:US:12

 

 

It looks fake, but it's from someone with 100% feedback, and who would go to the trouble to fake a Peavey amp? :confused:

 

 

But if it's real, don't bid on it, I'm the King of cheap tube amps :mad: :mad: :D :D

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Originally posted by Craigv

This part is weird:


"and rated at 120 watts into 8 ohms, 175 watts into 4 ohms, and 200 watts into 2 ohms"



I know of no tube amp with an output transformer that has differing output into different impedance loads. It's obviously got an output xformer, and it has no impedance switching.

 

 

+1

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Originally posted by Craigv

This part is weird:


"and rated at 120 watts into 8 ohms, 175 watts into 4 ohms, and 200 watts into 2 ohms"



I know of no tube amp with an output transformer that has differing output into different impedance loads. It's obviously got an output xformer, and it has no impedance switching.

 

 

 

I as well noticed that, which was what made me wonder.

 

But maybe he just doesn't understand tube amps...

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Ok, this is interesting.

 

Peavey has a manual for this amp.

 

And, it does indeed claim those changing power ratings. Odd.

 

They mention some sort of switching system on the speaker jacks, is it possible that the jacks could automatically switch output taps, which are (???) rated for different amounts of power :confused:

 

http://www.peavey.com/search.cfm?c=3&term=vta

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Originally posted by megadan

Ok, this is interesting.


Peavey has a manual for this amp.


And, it does indeed claim those changing power ratings. Odd.


They mention some sort of switching system on the speaker jacks, is it possible that the jacks could automatically switch output taps, which are (???) rated for different amounts of power
:confused:

http://www.peavey.com/search.cfm?c=3&term=vta

 

Yeah that makes even less sense..."the output impedance is approximately 2 ohms per pair of jacks". Huh???? Speakers have impedance, not jacks. So if I plug an 8 ohm speaker into the first jack, what does it mean?

 

The output table lends more confusion....output increases until you get to 1 ohm where it drops back to the same output as with an 8 ohm load.

 

Weird.

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Very.

 

 

According to this quite interesting little book apparently written by the founder of Peavey, the VTA 400 was the first all tube amp Peavey made, and the first amp to have overdrive!

 

http://www.peavey.com/support/technotes/hartley/chapter_1.pdf

 

(that is, selectable overdrive at low volumes. He goes on to explain how someone else then beat him to footswitchable distortion, which he should have thought of but didn't)

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The output transformer has a single secondary winding, no taps. That's the only way it will behave that way. The power amplifier must be set up such that the plate impedance is within the parameters of the tubes for a variety of load impedances. There is an optimal load impedance (in this case 2 Ohms) and any variation off that (up or down) will result in a decrease in output power. It's not an optimal implementation.

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Originally posted by Viggen

Well, once I almost bought a Peavey Alphabass(all tube). According to the manual this amp had different outputs with different speakerloads. Verry similar to this VTA 400...

:confused:
Didn't buy it... Bought my Mesa a week later:thu:

 

The Alphabass I owned was rated for 160W into 4 or 2 Ohms, via two taps on the output transformer. As far as I can recall, they were all like that. Great sounding amp, but not loud enough.

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