Impedance matching

nogoodboyo · 17th March 2006, 08:54 PM

Hi

I have speakers with impedance of 6ohms. My PP amp's OPT's have taps for 4 and 8 ohms. What should I do?

TIA

Tubes4e4 · 17th March 2006, 09:12 PM

Quote:

I have speakers with impedance of 6ohms. My PP amp's OPT's have taps for 4 and 8 ohms. What should I do?

Technically, the 4 Ohms tap should be better suited. But just chose the tap that sounds best to you. Chances are that it would be the 4 Ohms tap, too, since it would give a somewhat better damping factor (and a bit less output power, but you won´t notice that by ear w/o measuring the actual Po).

Tom

ray_moth · 17th March 2006, 10:48 PM

You don't mention in what mode your OP tubes are connected and this makes a difference, as I'll try to explain below:

* With triodes or triode-strapped beam tetrodes/pentodes, it's better to err on the side of a higher impedance than a lower impedance, so use the 4 ohm tap with a 6 ohm speaker.

* In tetrode/pentode mode, the opposite is true, i.e. it's better to load them with a lower impedance, by using the 8 ohm tap with a 6 ohm speaker.

* For ultralinear connection, there is more leeway and it probably doesn't really matter which tap you use. However, in general with UL, using a higher load impedance (the 4 ohm tap) will give less power and less distortion, while using a lower impedance (the 8 ohm tap) will have the opposite effect.

The above is just a general guideline and what works best for you may depend very much on your actual speakers. As you're probably aware, the nominal impedance of a speaker is an average that sometimes doesn't mean too much; the actual impedance can vary all over the place with frequency, depending on speaker design.

nogoodboyo · 17th March 2006, 11:55 PM

Thanks for your answers

It's wired ultralinear, I've had it running on 4ohms and it was load enough; I was just worried about damaging something.

17th March 2006, 08:54 PM	#1
nogoodboyo diyAudio Member Join Date: Dec 2004 Location: SF Bay Area	Impedance matching Hi I have speakers with impedance of 6ohms. My PP amp's OPT's have taps for 4 and 8 ohms. What should I do? TIA

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
Impedance Matching	maxzimum	Solid State	2	9th April 2009 02:03 PM
Impedance matching	netster403	Solid State	4	11th July 2007 12:06 AM
Impedance matching	Triod lover	Tubes / Valves	2	12th January 2007 09:59 AM
Need help understanding transformer impedance ratios and impedance matching	percy	Tubes / Valves	5	28th February 2005 08:35 PM
Impedance Matching	bryce66	Solid State	6	9th November 2001 09:02 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


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

17th March 2006, 10:48 PM	#3
ray_moth diyAudio Moderator Emeritus Join Date: Jan 2004 Location: Jakarta	You don't mention in what mode your OP tubes are connected and this makes a difference, as I'll try to explain below: * With triodes or triode-strapped beam tetrodes/pentodes, it's better to err on the side of a higher impedance than a lower impedance, so use the 4 ohm tap with a 6 ohm speaker. * In tetrode/pentode mode, the opposite is true, i.e. it's better to load them with a lower impedance, by using the 8 ohm tap with a 6 ohm speaker. * For ultralinear connection, there is more leeway and it probably doesn't really matter which tap you use. However, in general with UL, using a higher load impedance (the 4 ohm tap) will give less power and less distortion, while using a lower impedance (the 8 ohm tap) will have the opposite effect. The above is just a general guideline and what works best for you may depend very much on your actual speakers. As you're probably aware, the nominal impedance of a speaker is an average that sometimes doesn't mean too much; the actual impedance can vary all over the place with frequency, depending on speaker design.

17th March 2006, 11:55 PM	#4
nogoodboyo diyAudio Member Join Date: Dec 2004 Location: SF Bay Area	Thanks for your answers It's wired ultralinear, I've had it running on 4ohms and it was load enough; I was just worried about damaging something.