Rotel amplifier query

[eddieg]

I have a Rotel amplifier - an RA-920 AX - which I bought many years ago (in the 20th century!).

When I put the headphone jack into the headphone socket it does NOT cut out the sound to the speakers (which, to me, defeats the purpose of using headphones)

I phoned Rotel support and they said the diagrams for the amp confirmed it was made that way but they could not explain why.

So two questions:

- what would have been the purpose of making an amplifier like that?

- what can I do to circumvent the problem?....ie, I want to be able to listen through headphones without any sound going through the speakers at the same time

Many thanks for any answers and suggestions

Eddie

 

[Petherick]

That does seem weird!

You may be able to change the headphone socket to one which 'breaks' when a plug is inserted. It depends how it's wired. Could you get the circuit diagram?

 

[eddieg]

Yes they did email me the circuit diagram but it means nothing to me as I am not technically gifted (to say the least)

Would a solution possibly be (to avoid getting inside the machine) the purchase of a (reasonably-priced) headphone amp?

 

[eggontoast]

Check out item number 271324803315 on eBay, they don't make these anymore but it will let you use your headphones with your existing amplifier.

 

[davedotco]

It was done for the same reason that some amps have a 'Direct' switch, ie keeping the signal path as 'pure' as posible.

Makes the phones a pain to use, silly idea.

Simple solution, if you use banana plugs, just disconnect the speaker cable, either end will do and just one plug. Easy.

I think your amp has a tape out so a conventional headphone amp will do nicely, just the cost issue for something decent.

 

[Petherick]

You'd have to unplug / plug in your sources when switching amps then, though. Which to me seems a bit of a pain. Don't you have anyone you could ask to delve inside?

Is it possible to post the circuit diagram somewhere? At least this would determine whether a new socket could be fitted.

EDIT - davedotco, what would a headphone amp add if the speakers were disconnected as you suggest?

 

[davedotco]

You'd have to unplug / plug in your sources when switching amps then, though. Which to me seems a bit of a pain. Don't you have anyone you could ask to delve inside?

Is it possible to post the circuit diagram somewhere? At least this would determine whether a new socket could be fitted.

If the amp is not designed to cut the output, then the rewireing could be quite complex. The headphone socket may not be driven from the main output stage. not something I would attempt.

 

[davedotco]

You'd have to unplug / plug in your sources when switching amps then, though. Which to me seems a bit of a pain. Don't you have anyone you could ask to delve inside?

Is it possible to post the circuit diagram somewhere? At least this would determine whether a new socket could be fitted.

EDIT - davedotco, what would a headphone amp add if the speakers were disconnected as you suggest?

Nothing.

Either just unplug the speakers and use the phones as normal, or connect a headphone amp to the tape output, I think the Rotel has one, but it has been a while since I have seen one.

 

[eddieg]

Thank you all for your responses....much appreciated

I think this: "connect a headphone amp to the tape output"....is probably the best solution....any suggestions which one and how much? (i really dont want to spend too much because this is only a temporary fix until I upgrade my whole system in a year or so)

....and yes the amp has a tape output and even more yes - it's a ridiculous way to design an amplifier

 

[jonomd]

Use to have a rotel 931 a while back myself which did the same thing. If i remember correctly there a 2 sets of speaker terminals on the back. Direct and switched. I'm sure that when speakers were attached to the switched terminals the headphone when connected would cut the amp out. Did not use it as i thought it affected the sound quality.

Don't know your amp though.

 

[Crocodile]

That QED box looks ideal but if you can't snag it cheaply, fit a two way speaker switch with nothing on the second speaker terminals. You can then switch the speakers off from there to save keep unplugging them.

 

[danrv]

If i remember correctly there a 2 sets of speaker terminals on the back. Direct and switched. I'm sure that when speakers were attached to the switched terminals the headphone when connected would cut the amp out.

Definately look into that. I had the same issue with my brother's Arcam Delta 90.2. Couldn't figure out why connecting headphones didn't cut the sound.

I then switched to the other set of speaker terminals and it was sorted.

 

[danrv]

deleted

 

[eggontoast]

That QED box looks ideal but if you can't snag it cheaply, fit a two way speaker switch with nothing on the second speaker terminals. You can then switch the speakers off from there to save keep unplugging them.

No need for the speaker switch. Just connect the amp and speakers to the QED box and your system functions as normal, plug the cans in the box and it cuts the speakers for headphone use. It should go cheap as it's been listed three times without selling already., cheaper than a headphone amp anyway. The other alternative would be to mod the amp, it's not a big job but is likely to cost more, approx £50 I should say.

 

[davedotco]

Use to have a rotel 931 a while back myself which did the same thing. If i remember correctly there a 2 sets of speaker terminals on the back. Direct and switched. I'm sure that when speakers were attached to the switched terminals the headphone when connected would cut the amp out. Did not use it as i thought it affected the sound quality.

Don't know your amp though.

Good call.

I certainly remmember some amplifiers being configured in that way, not sure about this specific model.

Take a look at the Fiio headphone amps, they have several models with a different facilities, maybe one of portable units that can be used with a mobile device when you upgrade.

 

[Crocodile]

No need for the speaker switch.

You may want to read my post again.

And to those suggesting the other set of speaker terminals, there aren't any.

 

[eggontoast]

You may want to read my post again.

Oops, sorry me bad.

 

[Crocodile]

You may want to read my post again.

Oops, sorry me bad.