HELP! - BERESFORD TC 2270 MKIII - 2 Way Speaker/amp switch

[irison]

Im hoping someone has experience with this switch and/or a similar one? Id like to know if this is an issue as Im not sure I follow what they are saying.

Per their website:
- Not recommended for use with valve amplifiers that cannot be switched off when not connected to a pair of speakers through the TC-7220 MKIII.

I have a new Yaquin MC 13S tube amp that I'm planning to connect to this switch (along with a Marantz 2270 receiver and 2 sets of speakers).

So I can't turn off my tube amp if my speakers are not connected through this switch? (I plan to have 2 set of speakers connected at all times)

 

[mroboto]

There must be a mistake.

You cannot turn ON a tube amp without speakers connected, to avoid destroying of outputs transformer.

The danger is to send a signal though the tubes and output transformer without a load (speaker).

But there is a possible fix.

I added 510 ohms 2W resistor directly between the 8 ohms + and - speakers output terminals, to always have a load on the outputs if something happens to the speakers or speakers cables when the amp is working.

I feel more confident with the resistor, or better disconnecting the amp AC cord before I disconnect the speakers.

 

[robert_kc]

Im hoping someone has experience with this switch and/or a similar one? Id like to know if this is an issue as Im not sure I follow what they are saying.

Per their website:
- Not recommended for use with valve amplifiers that cannot be switched off when not connected to a pair of speakers through the TC-7220 MKIII.

I have a new Yaquin MC 13S tube amp that I'm planning to connect to this switch (along with a Marantz 2270 receiver and 2 sets of speakers).

So I can't turn off my tube amp if my speakers are not connected through this switch? (I plan to have 2 set of speakers connected at all times)

I suggest that you read this:

Looking for a good multi speaker selector

 

[irison]

There must be a mistake.

You cannot turn ON a tube amp without speakers connected, to avoid destroying of outputs transformer.

The danger is to send a signal though the tubes and output transformer without a load (speaker).

But there is a possible fix.

I added 510 ohms 2W resistor directly between the 8 ohms + and - speakers output terminals, to always have a load on the outputs if something happens to the speakers or speakers cables when the amp is working.

I feel more confident with the resistor, or better disconnecting the amp AC cord before I disconnect the speakers.

Thanks I appreciate the info. I knew about keeping the speaker load on the tube amp but was hoping the switch would do that.

 

[irison]

I suggest that you read this:

Looking for a good multi speaker selector

Thanks. I will read through the links and subsequent info.

 

[peterh]

There must be a mistake.

You cannot turn ON a tube amp without speakers connected, to avoid destroying of outputs transformer.

The danger is to send a signal though the tubes and output transformer without a load (speaker).

But there is a possible fix.

I added 510 ohms 2W resistor directly between the 8 ohms + and - speakers output terminals, to always have a load on the outputs if something happens to the speakers or speakers cables when the amp is working.

I feel more confident with the resistor, or better disconnecting the amp AC cord before I disconnect the speakers.

This is a good advise. I would however use 100 ohm as a permanently connected resistor, grabbing about a watt of available output power ( for a EL84 type amp), something the ears does not notice.

 

[irison]

This is a good advise. I would however use 100 ohm as a permanently connected resistor, grabbing about a watt of available output power ( for a EL84 type amp), something the ears does not notice.

I sent a message to Beresford (maker of these switches) and was informed they have a unit - TC 7210 that works with Tube Amps. It has this functionality. I may go with this option.

• Dummy load resistors to guard against open load conditions on the amplifier outputs

 

[mroboto]

I sent a message to Beresford (maker of these switches) and was informed they have a unit - TC 7210 that works with Tube Amps. It has this functionality. I may go with this option.

• Dummy load resistors to guard against open load conditions on the amplifier outputs

Adding one resistor directly to the tube amp output terminals , inside the amp would be safer, as if one cable disconnect :/

And the switch box don't know if you use a 4 or 8 ohms speaker, and connected to the 4 or 8 ohm tap ot the amp.