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#26 pre amp
#26 pre amp
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Old 3rd June 2018, 03:23 PM   #4631
Yaho is offline Yaho  United States
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Andy thanks for the reply,

Quote:
You'd need to use a mains transformer with a higher voltage since you'd be losing volts.
My main transformer output is 18v at 2A. So that should be plenty to work with.
Quote:
And for good condition 01As the later ST shape ones are a better bet
I was under the assumption that the globes sounded better than the ST. I just bought 3 (supposedly) NOS Globes but I have no way of testing them. My tube tester is not capable of checking ancient tubes. But I will look for ST tubes.

Do you think my little 0.5hy DCR 18ohm chokes can be utilized for choke input for 01a? I can play around since i have a bunch of them.

thanks,
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Old 4th June 2018, 07:20 PM   #4632
stocktrader200 is offline stocktrader200  Canada
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10v p-p tube signal on a 100k pot will outperform virtually any volume device.
3db per step is almost useless.

Last edited by stocktrader200; 4th June 2018 at 07:30 PM.
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Old 4th June 2018, 07:58 PM   #4633
pieter t is offline pieter t  Netherlands
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Quote:
Originally Posted by stocktrader200 View Post
10v p-p tube signal on a 100k pot will outperform virtually any volume device.
Blanket statement....

Quote:
Originally Posted by stocktrader200 View Post
3db per step is almost useless.
That has nothing to do with the way the volume is controlled
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Old 5th June 2018, 08:30 AM   #4634
sumotan is online now sumotan  Indonesia
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Hi Guys, Slightly OT question. Am gathering psu parts to build up Ale's 01a gen 2 preamp. Regarding the LCLC supply, is there any advantage to be had if I Tee off after the first capacitor & supply each channel with it's own choke & capacitor ? Meaning in all there'll be 3 chokes instead.

Thks
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Old 5th June 2018, 08:45 AM   #4635
andyjevans is offline andyjevans  United Kingdom
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I've never heard any difference in splitting the HT into two channels. I'd put all the chokes in the one supply. Others might be able to hear a difference. More important for me is each stage has an independent supply.
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Old 5th June 2018, 08:55 AM   #4636
sumotan is online now sumotan  Indonesia
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Hi Andy
Thanks for the reply. Thought that I might get away by creating a seudo mono supply of sorts. My thinking being that it might minimize cross talk as the choke is there to do some blocking. 2 individual supplies means 2 AZ1. Lol

Thanks again
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Old 5th June 2018, 08:56 AM   #4637
awkwardbydesign is offline awkwardbydesign  England
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Quote:
Originally Posted by stocktrader200 View Post
10v p-p tube signal on a 100k pot will outperform virtually any volume device.
3db per step is almost useless.
Depends on what you mean by outperform. A TVC on the output of my 01A cuts out the hum, which with the excessive gain of the gyrator, can be unbearable. My power amp is 250W at 1V input! The 26 suits that better, with a pot on the input.
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ABD.
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Old 5th June 2018, 08:56 AM   #4638
andyjevans is offline andyjevans  United Kingdom
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Quote:
Originally Posted by Yaho View Post

I was under the assumption that the globes sounded better than the ST.
I can't hear much difference - these 01A tubes are so old that the condition of the tube is probably more important than the type of tube. STs are newer generally. I have a bunch of globes that don't work with Ale's gyrator - the voltages won't come into range with the stated component values. I ended up with only a small part of my stock being usable, and those were almost all ST shape. Maybe I had some component failures in the gyrators - couldn't find the reason since I'm not good with solid state. Anyway, for globes I've been using plate chokes as an alternative. I like plate chokes anyway so I've also been using them with the 2P29L, my daily listen, which as far as I know also works just fine with Ale's gyrator. So what I'd say is start with Ale's gyrator and see how it goes with your globes. If you have any issues you can always swap in a 2P29L, which I prefer to the 26 plus it's a simpler filament supply.
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Old 7th June 2018, 11:25 PM   #4639
Yaho is offline Yaho  United States
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Hi thanks for the insightful reply. I will be mindful of your comments, indeed.

Quote:
I like plate chokes anyway
I've read your blogs some where in the web universe that said that you've employed 2 hammond chokes in series to accomplish this. For whatever the reasons are i can not find those blogs.

thanks again,
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Old 8th June 2018, 09:08 AM   #4640
andyjevans is offline andyjevans  United Kingdom
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I've moved on to NP Acoustics. Vietnamese transformer maker that makes very good value amorphous core transformers.
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