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Old 10th April 2003, 03:52 PM   #11
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true...

I have an ECC99 running at 150v, 18mA 4v bias. gain is 22.

Bias on output is around 50v. So.... for I need around 2v input for full output. The ECC99 is IT coupled with a 1/1:1 phase splitter to the grids of the 6B4G.

So you are correct.

I'd still like a total voltage gain of around 5 for my pre-amp.

And i'd like to do PP with the 71a's,
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Old 10th April 2003, 03:55 PM   #12
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Quote:
Originally posted by Joel
....... in order to get a gain of 8 to your power amp that was poorly designed to begin with, since it has an input sensitivity of a whopping 4V!

sheesh.
.
So, Joel

please tell me what input sensitivity has to do with whether an amp is
poorly designed or not. I'm really curious.......


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Old 10th April 2003, 04:33 PM   #13
Joel is offline Joel  United States
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Jan,

I should have said "IMO". But it is fairly accepted that power amplifiers should have an input sensitivity of ~1V. This was the standard throughout the 40's-60's.

What's my point? My point is that if you design the power amp to go to full power with 1-2V input, then you can eliminate the preamp altogether if using a digital source. That's a plus. Even the best preamp is less transparent than a wire.
This is of course a moot point if you need phono gain.

Is anything I'm saying controversial? I would think it was self-aparent...
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Old 10th April 2003, 05:10 PM   #14
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hi RichardJones,

if u like the old tubes.
will U considerate the 01A.
its cheap in ebay.

may be another choice to U.

thanks

Thomas
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Old 10th April 2003, 06:14 PM   #15
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Hi, Joel , all

I'm just curious, that's all.
We , as amateurs, have a freedom of choice, we can go in every direction,
we can build anything we want.
We are not bound by comercial interests, we don't have to be "sensible".

Quote:
Originally posted by Joel
Jan,

I should have said "IMO". But it is fairly accepted that power amplifiers should have an input sensitivity of ~1V. This was the standard throughout the 40's-60's.


Accepted by whom? Who cares?

By all means, we should study the old masters, learn all we can, but I don't see why
we should restrict ourselves to building stuff the same way they did in the ' 60s

Let's go the other way. Let's try new configurations, and new unusual valves,
our journey is filled with endless possibilities


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Old 10th April 2003, 06:23 PM   #16
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Default SURE,....BUT....

Hi,

Quote:
Accepted by whom? Who cares?
You should at least adhere to some standards IMO.

One of them is the input sensitivity of an amplifier, if you don't do this than you'll inevitably end up with compatiblity problems.

Unless you're building everything from scratch, CDPs included?

Caveat emptor,
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Old 10th April 2003, 06:35 PM   #17
Joel is offline Joel  United States
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Jan, give me a break, please. I hardly think saying that one should try to shoot for a 1V input sensitivity is stifling anybody's creativity - or living in the "60's".

Plus, you obviously don't read the forum that often, as I have built and posted schematics of amps using very un-sixties ideas, and technology. I don't own a 12AX7, EL34, or a push-pull amp of any kind. So can you spare me the lecture on freeing our minds please? Thanks.
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Old 10th April 2003, 06:39 PM   #18
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Hi Frank,

You are right,
it probably means that you have to build all your stuff youself,
that gives you more posibilities , don't you think?

Cheers
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Old 10th April 2003, 06:43 PM   #19
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Quote:
Originally posted by Joel
Jan, give me a break, please. I hardly think saying that one should try to shoot for a 1V input sensitivity is stifling anybody's creativity - or living in the "60's".

Plus, you obviously don't read the forum that often, as I have built and posted schematics of amps using very un-sixties ideas, and technology. I don't own a 12AX7, EL34, or a push-pull amp of any kind. So can you spare me the lecture on freeing our minds please? Thanks.
Hi Joel

No, I don't read the forums that often , I just reacted to this one post from you,
and was curious as to why you was so negative towards Richards linestage?

Cheers
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Old 10th April 2003, 06:58 PM   #20
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Default jealousy?

hmmm... maybe he is jealous that he didn't think of this linestage before me?

just kidding.

anyway.... is everyone gonna argue about "standards" or answer my questions in the original post?????

TXS!!!!
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