Aleph 4 Strickly DIY Project Build - Page 11

generg · 17th May 2011, 02:54 PM

pumpkin has an amplification of ten, thought for F4 without any amplification. What input voltage does your amp need?
Maybe 1 V only?

Andy5112405 · 03:25 PM

The noise is there with no input signal applied.

10 x Nothing should be Nothing. Even if the A700 has a more sensitive input ?

The Aleph isn't finished yet, the Shuntky / Pumpkins are being built in preparation for the big day.

generg · 17th May 2011, 03:07 PM

when your amp has also 20db amplification pumpkins amplification must be reduced.
an older ML I just googled even had 26db amplification.

Andy5112405 · 17th May 2011, 04:08 PM

All this would help to explain the WHITE NOISE but not the POPPING.

generg · 17th May 2011, 04:09 PM

what is popping?

poor German...

Andy5112405 · 17th May 2011, 04:14 PM

Quote:

Originally Posted by generg

what is popping?

poor German...

The amplifier is making an intermittent "Pop" sound with no input attached and with the volume set to maximum.

Zen Mod · 17th May 2011, 06:16 PM

set gain to 4-5x

try fully open pot , fully unloaded input with any tube preamp (for instance) - and you're looking for trouble

same with Pumpie

Andy5112405 · 17th May 2011, 07:06 PM

As they always say, "You learn something every day".

If I had a signal applied under the conditions mentioned the Power Amp would be pushing over 60W into the speakers so you wouldn't hear the noise anyway. The only problem would be that you would hear the noise during quiet passages.

I'll leave the gain as it is for the time being as the noise may be a function of the increased gain of the A700. I'll see what it is like with the Aleph 4.

Zen-Mod, when you say unloaded input do you mean no signal or shorted input pins?
I would expect an amplifier with shorted input pins to be silent, ie amplifying nothing.

Although I rarely use the amp at full volume there will be occasions when you may wish to do so. I would not expect to hear "pops" from the speakers during the quiet passages...

Zen Mod · 17th May 2011, 07:21 PM

problem is if you are doing those things* to highly sensitive input , as Pumpkin have ; not thinking about gain , but on sensitivity ... if I'm putting that correctly

* leaving input "open" - without source , where input is projected to work with finite source resistance . that way circ loose programmed gain , because inputs are flapping on breeze .....

I can bet that - if everything is OK - you'll not have any pops or whatever if you connect some source to Pumpkin's input , with pot where it belongs - between source and Pumpie input

Generg ( and few other builders) made similar mistake in past - using Pumpkin set to highish gain , with amps needing just line level for full throttle ..... after setting to moderate/adequate gain , problems were solved

generg · 17th May 2011, 07:36 PM

Andy do you know how to set the gain to 3-4? One way is to change the feedbackresistor from 100k to 38k-41k, or rise the 10k in the inputs to 25-30k....

Is this correct Zen?

17th May 2011, 02:54 PM	#101
generg diyAudio Member Join Date: Jul 2009 Location: Near Frankfurt	pumpkin has an amplification of ten, thought for F4 without any amplification. What input voltage does your amp need? Maybe 1 V only? __________________ and the First Wtt is......a really First Class PSS Idea !

17th May 2011, 03:04 PM	#102
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	The noise is there with no input signal applied. 10 x Nothing should be Nothing. Even if the A700 has a more sensitive input ? The Aleph isn't finished yet, the Shuntky / Pumpkins are being built in preparation for the big day. Last edited by Andy5112405; 17th May 2011 at 03:25 PM.

17th May 2011, 03:07 PM	#103
generg diyAudio Member Join Date: Jul 2009 Location: Near Frankfurt	when your amp has also 20db amplification pumpkins amplification must be reduced. an older ML I just googled even had 26db amplification. __________________ and the First Wtt is......a really First Class PSS Idea !

17th May 2011, 04:09 PM	#105
generg diyAudio Member Join Date: Jul 2009 Location: Near Frankfurt	what is popping? poor German... __________________ and the First Wtt is......a really First Class PSS Idea !

17th May 2011, 06:16 PM	#107
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	set gain to 4-5x try fully open pot , fully unloaded input with any tube preamp (for instance) - and you're looking for trouble same with Pumpie __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb


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17th May 2011, 04:08 PM	#104
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	All this would help to explain the WHITE NOISE but not the POPPING.

17th May 2011, 07:06 PM	#108
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	As they always say, "You learn something every day". If I had a signal applied under the conditions mentioned the Power Amp would be pushing over 60W into the speakers so you wouldn't hear the noise anyway. The only problem would be that you would hear the noise during quiet passages. I'll leave the gain as it is for the time being as the noise may be a function of the increased gain of the A700. I'll see what it is like with the Aleph 4. Zen-Mod, when you say unloaded input do you mean no signal or shorted input pins? I would expect an amplifier with shorted input pins to be silent, ie amplifying nothing. Although I rarely use the amp at full volume there will be occasions when you may wish to do so. I would not expect to hear "pops" from the speakers during the quiet passages...

17th May 2011, 07:21 PM	#109
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	problem is if you are doing those things* to highly sensitive input , as Pumpkin have ; not thinking about gain , but on sensitivity ... if I'm putting that correctly * leaving input "open" - without source , where input is projected to work with finite source resistance . that way circ loose programmed gain , because inputs are flapping on breeze ..... I can bet that - if everything is OK - you'll not have any pops or whatever if you connect some source to Pumpkin's input , with pot where it belongs - between source and Pumpie input Generg ( and few other builders) made similar mistake in past - using Pumpkin set to highish gain , with amps needing just line level for full throttle ..... after setting to moderate/adequate gain , problems were solved __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

17th May 2011, 07:36 PM	#110
generg diyAudio Member Join Date: Jul 2009 Location: Near Frankfurt	Andy do you know how to set the gain to 3-4? One way is to change the feedbackresistor from 100k to 38k-41k, or rise the 10k in the inputs to 25-30k.... Is this correct Zen? __________________ and the First Wtt is......a really First Class PSS Idea !

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