[brospin]

Can the gain factor be easily increased in any portable headamp? I once read a thread by Ray Samules who said he could do so by only changing 2 resistors in an SR-71. Is this the rule for all headamps? Does an increase in gain alter sound quality?

 

[PeterR]

Usually that should be no problem. Why do you want to do this?

 

[brospin]

Quote:

Originally Posted by PeterR Usually that should be no problem. Why do you want to do this?

I use a Rudistor Nkk-01 amp for portable with an iMod as source. Relatively low output level of the iMod (1V) + low gain factor of the amp (max 8dB) + relatively high impedance for portable phones (Ety ER4-S 100 Ohm) + listening to classical (low level recordings: RMS typically around -25 to -30dB) sometimes makes me feel like I need more power or have to work with the volume setting close to maxium. A higher gain factor would be welcome (e.g. 15dB).

 

[pegasus21]

Yes it's true that changing only 2 resistors (1 for each channel) will change the gain. This is true with most setups. However there are pros and cons in having a single stage amplifier wired with a high gain as opposed to multiple smaller gain amplifiers.

I don't think I should go into the details since I'm probably not versed enough to comment on the internals.

In general, multiple staged amplifiers are used mostly in the higher costing amplifiers. For portable, single stage would be better since there's a space limitation.

 

[PeterR]

Quote:

Originally Posted by brospin sometimes makes me feel like I need more power or have to work with the volume setting close to maxium. A higher gain factor would be welcome (e.g. 15dB).

"Close to maximum" or "hitting the end stop but still not loud enough"? Increasing the gain will only help if it's the latter, else it won't achieve anything you couldn't do easier by just mounting the volume knob in a different position.

 

[brospin]

Quote:

Originally Posted by PeterR "Close to maximum" or "hitting the end stop but still not loud enough"? Increasing the gain will only help if it's the latter, else it won't achieve anything you couldn't do easier by just mounting the volume knob in a different position.

Usually I don't reach the maximum level and have a good listening volume, but I am close to it. It is still that I like to have a power reserve for the case it could be needed. It's like driving a car and having a power reserve under your right foot. In case needed, you push the throttle deeper and you resolve the situation.

 

[brospin]

Quote:

Originally Posted by pegasus21 Yes it's true that changing only 2 resistors (1 for each channel) will change the gain. This is true with most setups. However there are pros and cons in having a single stage amplifier wired with a high gain as opposed to multiple smaller gain amplifiers. I don't think I should go into the details since I'm probably not versed enough to comment on the internals. In general, multiple staged amplifiers are used mostly in the higher costing amplifiers. For portable, single stage would be better since there's a space limitation.

I don't know if the amp I use (Rudistor NKK-01) uses single stage or multiple stage amps. I haven't found any internal picture of the amp or additional info about the layout and I don't have the intention to open mine.

 

[PeterR]

Quote:

Originally Posted by pegasus21 a single stage amplifier

This certainly isn't, even though it may be just one package...
Quote:

wired with a high gain

We're far away from anything you'd call high gain here...

Quote:

Originally Posted by brospin I don't know if the amp I use (Rudistor NKK-01) uses single stage or multiple stage amps. I haven't found any internal picture of the amp or additional info about the layout and I don't have the intention to open mine.

According to the web site it uses a "BTL (huh?) power IC", sounds like a chip amp. You probably can set the gain by external resistors, but some chips have a fixed internal gain you can't do anything about. If you don't intend to pop the hood on your amp, the only way to find out would be asking Rudistor.