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Old 14th March 2013, 11:00 AM   #1461
stajo is offline stajo  Sweden
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Originally Posted by Salas View Post
Yes, but they have something in common, they both can smoke without warning.
No biggie. I can do that too
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Old 14th March 2013, 11:02 AM   #1462
Salas is offline Salas  Greece
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Well, we momentarily forgot about Stajo brand. Apologies.
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Old 14th March 2013, 11:16 AM   #1463
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Here is legit question...I think. Some folks say that you want your pre doing most of the gain, getting signal out of the dirt, others say, why throw away so much gain, if it is not needed. I will have very efficient system, so which is better?
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Old 14th March 2013, 11:25 AM   #1464
stajo is offline stajo  Sweden
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There is no gain in more gain then you need
But surely, its better to have most gain where you have a fairly disturbance free surrounding. High gain in the first stages of a power amp for example can easily be affected by a badass trafo for example. The gain needed in your pre is predicted by the sensitivity of your Fujiyama, imho.

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Old 14th March 2013, 11:28 AM   #1465
Salas is offline Salas  Greece
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Read Pano's gainstructure article.
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Old 14th March 2013, 11:36 AM   #1466
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ah. Forgot about that one. DOnt be talking about my mountain, Stajo.
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Old 14th March 2013, 12:08 PM   #1467
stajo is offline stajo  Sweden
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What is Gain Structure?
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Old 14th March 2013, 12:52 PM   #1468
6L6 is offline 6L6  United States
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Quote:
Originally Posted by harlee View Post
Just for the record, I used 2 point grounding like Sakuma. Absolutely no audible hum, at least in my system.
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Originally Posted by Salas
Sakuma was talking the same thing as American engineers call bus bar grounding?
Very similar - see here: Inside Sakuma Amplifier


(Yes, this is from an old post, but I was re-reading this thread and thought you would like to see the link.)
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Old 14th March 2013, 01:07 PM   #1469
vgeorge is offline vgeorge  Greece
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In my build where they are standing near the bottom cover and the 317 sink they get hot and I did not trust 2W. In George's that the box has height and the 317s dissipate at an angle on a large plate maybe 2W they would suffice. After long time some of my tubes tended to give more heater emission and I adjusted them to 20Ω//3.3Ω finally. So even my happier tubes don't overheat. Thermals and voltages are to be checked and adjusted if necessary in individual builds of course. Even another LM317 brand can have a bit different Vref etc.
To get the correct voltage I had to use 20R//3.3R//39-47R MF 0.5W depending on the tube.
Regarding the cement resistors, this is what I had in my stash now. Hope they won' t hurt the sound.
Also I lifted the heaters to around 45V.
In fact I built this amp with everything I had on hand already. I only bought the tubes.
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Old 14th March 2013, 01:13 PM   #1470
vgeorge is offline vgeorge  Greece
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Fukushima?
Vgeorge, I want th elow down on your Speakers. I have some Altec 416's and 288's sitting here waiting on boxes. I was going to put the 416's in a large Ml-TWQT, showing pretty flat response down to 35, with nic slow taper. I am afraid I dont have the rrom for true bass horns like yours. The 18's look like they are from AE.
Buzz, I am using a combination of horn bass reflex from 80Hz to about 700Hz.
Regarding your 416, the thing is how well they are going to integrate with the horn and at what sensitivity, if you plan to use only one amplifier. With what horn are you planing to use your 288 with? For bass they are TD15X from Lambda, before they were taken over by AE. The box is big because I already had it and had the room for it. My plan is to integrate with the main speakers sometime in the future.
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