Connecting Ultra to vintage amplifier

[Swan55]

Hello,

We are slowly resurrecting our music system from 40 years ago (bought in the early 1980s) which has gathered dust for many years in a dry environment.

We've already re-foamed the speakers and they sound fine (Heybrook HB1)

And now wish to plug our old amplifier into the setup. It is a Nytech CA202. The plan is to connect the Ultra via RCA into the Nytech, and then the amp directly to the speakers.

The input connector on the back of the Nytech is a 5 pin DIN with the text " Aux 100mv "

So before I blow anything up, can anyone advise if we should be ok ?

many thanks

 

[Ronnie D]

Aux 100mv

The minimum RCA output from the Ultra is 200mv, so I don't know if that would work. I know one of the members use an attenuator so that might work

 

[Valentino]

As @Ronnie D says set the ultra to 200 mV. That should be ok. If it’s too much you can set all Ultra inputs to -6dB.
I presume you have an RCA to DIN cable, @Swan55?

 

[harkpabst]

It is a Nytech CA202.

Has the CA202 been overhauled at some point in time or is it still in its original state?

Unlike the later CA102 Obelisk (which suffered from insufficient cooling), the CA202 should be thermally stable. But after more than 4 decades it would certainly benefit from a re-capping. It's not just about the buffer capacitors in the power supply. The Nytech amps use one big capacitor per channel to decouple the speakers from the DC component in its output voltage. These caps are crucial to the amplifier concept.

You probably know about the "new" Nytech Audio providing service for the vintage amps also.

PS:
As @Ronnie D and @Valentino pointed out, the WiiM Ultra will work fine with the Nytech CA202.

 

[Swan55]

The minimum RCA output from the Ultra is 200mv, so I don't know if that would work. I know one of the members use an attenuator so that might work

Thanks Ronnie, and thank you as well for the private message.

I've searched the Home app and found the audio settings for reducing the output to 200; so we'll try that and i'll report back.

 

[Swan55]

As @Ronnie D says set the ultra to 200 mV. That should be ok. If it’s too much you can set all Ultra inputs to -6dB.
I presume you have an RCA to DIN cable, @Swan55?

thanks Valentino;
I'll be taking your and Ronnie's advice and set it to 200, then report back.

Yes I already have a converter cable; luckily, when we packed up the equipment I stored that as well (originally used to connect a Yamaha tuner to the Nytech).

 

[Swan55]

Has the CA202 been overhauled at some point in time or is it still in its original state?

Unlike the later CA102 Obelisk (which suffered from insufficient cooling), the CA202 should be thermally stable. But after more than 4 decades it would certainly benefit from a re-capping. It's not just about the buffer capacitors in the power supply. The Nytech amps use one big capacitor per channel to decouple the speakers from the DC component in its output voltage. These caps are crucial to the amplifier concept.

You probably know about the "new" Nytech Audio providing service for the vintage amps also.

PS:
As @Ronnie D and @Valentino pointed out, the WiiM Ultra will work fine with the Nytech CA202.

Hello Harkpabst,

It is still in its original state, bought brand new by myself.

I take you point regarding the capacitors etc.

Thank you for the pointer the "new Nytech"; And as it happens I did know about them and their servicing and upgrade options. In fact I have recently been discussing my situation with their Phill, who has given excellent advice regarding servicing, and also regards the external surface of our unit, where the powder coating is flaking away and some light surface rust is emerging (Phill can renew that as well.)

kind regards

 

[Swan55]

Hello everyone, and thanks for your advice to date.

Whilst we are here: do the DIN input sockets on the Nytech offer any sonic improvements compared to the RCA phonos that eventually replaced them ? Just wondering.

 

[harkpabst]

Hello everyone, and thanks for your advice to date.

Whilst we are here: do the DIN input sockets on the Nytech offer any sonic improvements compared to the RCA phonos that eventually replaced them ? Just wondering.

Companies like Naim and Nytech used to say so in the past ... but honestly ... no, not really.

One advantage of the DIN connection is that the ground makes contact first. But that doesn't affect the sound quality, it's rather a matter of operational safety. It'sa single plug only, so more convenient, too. A potential disadvantage is that the setup is less symmetrical between channels, but that's of little practical relevance. While Nytech always use cheap DIN sockets (before they converted to RCA), Naim used to use the fantastic lockable DIN connectors from Preh. However, they list me when they started explaining that their devices would sound better with the lock undine or even the locker ring cut and removed.

 

[Swan55]

ok, it's now a few days later, and here are our results :-

With the output from the Ultra reduced to 200mv, the output level from the Nytech was (predictably) very low, and needed the Nytech volume to be turned up to its highest levels for us to hear music satisfactorily.
Increasing the Ultra output through all its steps back up to 2000, gradually increased the input levels and allowed us to reduce the Nytech volume to achieve the same music output. Again, all predictable.
With the Ultra output back at 2000, the Nytech worked ok, and did not appear to overheat etc. - although I don't know what the longer term effect might be, if any, on the Nytech internal components from having a much higher input signal level from the Ultra.

So thanks to everyone for their advice on our posts original question.

 

[slartibartfast]

ok, it's now a few days later, and here are our results :-

With the output from the Ultra reduced to 200mv, the output level from the Nytech was (predictably) very low, and needed the Nytech volume to be turned up to its highest levels for us to hear music satisfactorily.
Increasing the Ultra output through all its steps back up to 2000, gradually increased the input levels and allowed us to reduce the Nytech volume to achieve the same music output. Again, all predictable.
With the Ultra output back at 2000, the Nytech worked ok, and did not appear to overheat etc. - although I don't know what the longer term effect might be, if any, on the Nytech internal components from having a much higher input signal level from the Ultra.

So thanks to everyone for their advice on our posts original question.

The high input signal won't cause any problems for the amplifier, it just means you will be using the lower part of the volume control range which may introduce channel imbalance at low volume levels. My Audiolab 8000A had an input sensitivity of 150mV and I used 10dB attenuators purely to allow more of the volume control to be used.

 

[Swan55]

But . . .
There is however a part 2 to our testing of connecting the Ultra to our 42 year old Nytech amplifier.
(we were also using our vintage Naim NACA4 speaker cable)


In our testing, we found that, with no equipment connected to the Nytech, that we had:-

* a buzzing noise through both loudspeakers but more so on the left channel, and
* loud interference "white noise" through both loudspeakers.

* interestingly, if we changed the Nytech input selector to either Aux or Tape (away from Disk), then the buzzing was immediately greatly reduced and the white noise almost disappeared (at amplifier 90% volume).

We were able to test with a different pair of speakers (same cable) and the results were the same.

With the amplifier set to Aux (to select our Ultra), then at our normal listening levels the white noise is not present and the buzzing noise is a very faint background noise (which I can hear if I listen out for it, but my wife cannot hear at all).

I'm assuming that these results indicate that the amplifiers internal components are indeed showing their age and a service is in order ?

The view of members would be welcome.

 

[Swan55]

The high input signal won't cause any problems for the amplifier, it just means you will be using the lower part of the volume control range which may introduce channel imbalance at low volume levels. My Audiolab 8000A had an input sensitivity of 150mV and I used 10dB attenuators purely to allow more of the volume control to be used.

Thanks slartibartfast - that's good to know. Much appreciated.