SimpleSE + Preamp

skipper · 13th December 2011, 12:16 AM

Hi All,

I have just added a preamp to my SimpleSE for the phono section. The preamp seems to have alot of gain. I do have a 50K volume pot on the amp.

1. Is it best to turn it up all the way and use the volume on the preamp (which then has a lot of gain)?
2. Turn the volume on amp half-way and use more of the preamp volume?
3. Disconnect the volume pot on the amp and use it directly.

If I diconnect the volume pot, will the output then be as if it is turned all the way up? Currently I play it with the amp volume all the way up.

Thanks!

boywonder · 13th December 2011, 01:39 AM

Quote:

Originally Posted by skipper

Hi All,

If I disconnect the volume pot, will the output then be as if it is turned all the way up? Currently I play it with the amp volume all the way up.

Thanks!

Yes. Replace the pot with an equal value resistor (50K in this case) to ground, and with top of the resistor connected to the input, it'll be the same as the volume "all the way up"

skipper · 13th December 2011, 05:10 AM

The schematics also are shown not to have the volume pot. Thats originally how I had it but at the time my only music input was an ipod. I controlled the volume through it.
Without the pot or resistor wouldn't that be maxed?

boywonder · 13th December 2011, 02:28 PM

The resistor (or pot) does a couple of things. It provides a load for the source (Ipod, CD player, etc) to drive so you want the resistance fairly high so that the voltage signal from the source stays high. Theoretically, no resistor or pot would be a very high impedance (the source would then be driving the input tube grid in parallel with the grid leak R (R11 &R21)) but if the impedance is too high it can be prone to noise and interference.

skipper · 13th December 2011, 03:24 PM

Ok, that is more clear now. I will leave the volume pot connect up on the amp.

Thank a bunch!

13th December 2011, 12:16 AM	#1
skipper diyAudio Member Join Date: Apr 2007	SimpleSE + Preamp Hi All, I have just added a preamp to my SimpleSE for the phono section. The preamp seems to have alot of gain. I do have a 50K volume pot on the amp. 1. Is it best to turn it up all the way and use the volume on the preamp (which then has a lot of gain)? 2. Turn the volume on amp half-way and use more of the preamp volume? 3. Disconnect the volume pot on the amp and use it directly. If I diconnect the volume pot, will the output then be as if it is turned all the way up? Currently I play it with the amp volume all the way up. Thanks!

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
SimpleSE - Reborn...again	cjkpkg	Tubelab	7	27th January 2011 12:21 AM
SimpleSE transformers	abacus	Tubelab	2	20th July 2010 07:56 PM
Need Some SimpleSE Help	gasser-dude	Tubelab	30	29th December 2009 12:12 AM
6V6GT in the SimpleSE	w5jag	Tubes / Valves	10	2nd May 2008 02:44 AM
SimpleSE and me	allyourzigg	Tubes / Valves	8	1st August 2007 02:44 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

13th December 2011, 05:10 AM	#3
skipper diyAudio Member Join Date: Apr 2007	The schematics also are shown not to have the volume pot. Thats originally how I had it but at the time my only music input was an ipod. I controlled the volume through it. Without the pot or resistor wouldn't that be maxed?

13th December 2011, 02:28 PM	#4
boywonder diyAudio Member Join Date: Jan 2008 Location: So.Cal.	The resistor (or pot) does a couple of things. It provides a load for the source (Ipod, CD player, etc) to drive so you want the resistance fairly high so that the voltage signal from the source stays high. Theoretically, no resistor or pot would be a very high impedance (the source would then be driving the input tube grid in parallel with the grid leak R (R11 &R21)) but if the impedance is too high it can be prone to noise and interference.

13th December 2011, 03:24 PM	#5
skipper diyAudio Member Join Date: Apr 2007	Ok, that is more clear now. I will leave the volume pot connect up on the amp. Thank a bunch!

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)