Connecting phones output from old receiver to Active monitors

[Rafa_Ghert]

Hey guys!

This is my first post here. I have been reading a lot of the discussions here for a few months now and have some questions that were somehow already outlined here, but I would like to know a few more of the details, if someone could enlighten me.

I have inherited a vintage Sansui turntable and receiver from my grandfather and would like to use them with my active Adam Audio T5V monitors. The turntable is the SR-212 and the receiver is the Sansui 210. My home studio is in a very small room and I only have room for these monitors that I already use for audio post production.

I know that I am able to connect to my active speakers through the 1/4'' stereo phone output by using a 1/4'' stereo to dual mono cable. However, as some people have mentioned in previous posts here, there is a risk that if the receiver volume level is set too high I could override the amps in the active monitors. I would like to know if there is a way to prevent that (apart from adjusting the volume knob in the receiver) or if I could somehow test the limit and know exactly at which point should I not go any louder on the receiver before it actually breaks the active monitor amplifier.

I also know I could use the tape rec outputs, but it's not something I would ideally want to do since I wouldn't be able to use the Eq controllers on the receiver. If, however, the level that comes out of the tape recs would be a more safe level for the active speakers, it is something that I could consider as an alternative.

As another resort, people have pointed out that I could buy a phono preamp and bypass the receiver altogether, since I'm only using it now because my turntable doesn't have an internal phono preamp. Nonetheless, I really wanted to use the receiver since I don't have a lot of money to buy another good preamp and wouldn't want to invest on a device that doesn't appear to be a very solid piece of equipment (here in Brazil I only found one in my price range that doesn't seem to be very reliable and well constructed).

Anyway, you can probably tell that I'm a little confused, so any help would be very much appreciated.



Thanks in advance )


PS: Just to recap the setup. Sansui SR-212 turntable ---> Sansui 210 stereo tuner amplifier ---> Mackie Big Knob ----> Adam Audio T5V monitors.

 

[swechsler]

This isn't really that big a deal (not really sure what you mean by "overriding the amps"; maybe you meant "overloading"?). At any rate, as long as the sound from the speakers is good, and undistorted, you're not overloading anything.

 

[Rafa_Ghert]

This isn't really that big a deal (not really sure what you mean by "overriding the amps"; maybe you meant "overloading"?). At any rate, as long as the sound from the speakers is good, and undistorted, you're not overloading anything.

Yes, that's what I meant. Because I'm using an amplifier (the sansui 210) before sending the signal to the active monitors that are already amplified by themselves.
Some members that commented on a 2013 post (Connecting old receiver to Active monitors) said that could happen if I were not careful enough with the volume control on the receiver.

But in any case, I was wondering if this idea of sending the signal through the receiver's phones output would be a good one or if anyone would have another suggestion.

 

[Semanon]

I second @swechsler’s comments. Turn it up until it sounds as loud as you want or starts to sound distorted or unpleasant. That’s your maximum level. In a small room, I’ll bet you get to ‘too loud’ well before you get to distortion.

Regarding a separate phono preamp, the phono pre in the 210 is pretty good, but a good quality modern pre will probably be an improvement. Keeping the 210 is about nostalgia and using a very cool piece of vintage equipment. If space becomes an issue, consider upgrading your system to get a phono pre.

Enjoy!

 

[lini]

(...) I would like to know if there is a way to prevent that (apart from adjusting the volume knob in the receiver) (...)

Sure, You could build yourself a custom cable with integrated voltage dividers (= two resistors per channel). Reducing the max output to 1/7 should easily do in your case, so you could for example go for 1.8 kOhm and 300 Ohm resistors.

Greetings from Munich!

Manfred / lini

 

[ecluser]

Since there is a built-in 220 Ohm resistor inside the Sansui, in series with the headphone output, you could attenuate the signal with only one resistor per channel. The value of that resistor is not critical, anything between 20 and 50 Ohm should provide enough attenuation. That resistor should be connected between the input (+) of the powered speaker and ground. It could be implemented inside the Sansui, on the headphone jack.

 

[lini]

Since there is a built-in 220 Ohm resistor inside the Sansui, in series with the headphone output, you could attenuate the signal with only one resistor per channel. The value of that resistor is not critical, anything between 20 and 50 Ohm should provide enough attenuation. That resistor should be connected between the input (+) of the powered speaker and ground. It could be implemented inside the Sansui, on the headphone jack.

Thought about that option as well, but I'd at least definitely not suggest an implemetation inside the Sansui. Simply because I wouldn't deem it unlikely, that the OP would prefer to still be able to alternatively use the headphone output as headphone output as well - and an implementation inside the Sansui would limit the usability of the headphone output especially in combination with classic headphone models with comparatively high impedance and moderate sensitivity (like for example the AKG K240M & K240DF - both with 600 Ohm and 88 dB/mW).

Well, and my suggested integration of complete voltage dividers with higher resistance into the cable was based on the thought, that for that purpose one would probably prefer to use pretty small resistor types with 1/4 or even just 1/8 W.

Greetings from Munich!

Manfred / lini