Technics RS-B965

[George S.]

Took me about 4 weekends to learn REW well enough to start understanding the basics. There is much I still don't as I'm just a hobbyist and not a Audio Engineer. This evening I'm going to give Audio Tester another go and will post how to calibrate the software to the soundcard if I get that far.
Have never had any luck with ASIO drivers or tried that "Asio for all". Even the experts seem to have issues with ASIO.
Have a ton of household chores to do first, including rustproofing the cars for the coming winter here in the US Great Lakes rust belt.

 

[vince666]

It's not impossible what you are saying.
Soundcard have 36,7/39 Ohm on the output and input cant be measured because it starts from 10 MOhms ang going up to over 20 MOhms.
965 have a 100.4/99.7 Ohms on the output and input is also over 10MOhms

interesting.... also my B965 have about 100 Ohms at their outputs.

Regarding the inability to use ASIO drivers (i mean the dedicated ones, not the ASIO for all) might mean that your card simply doesn't support them?
On my cards here, I always choose their own dedicated ASIO drivers... the only time I had to use the ASIO for ALL drivers was MANY years ago with a Creative Soundblaster Live! PCI soundcard but, soon after, I switched to another card which had its own ASIO drivers, properly supported.

About those "mono, right, left, stereo" settings at your audiotester, I never happened to touch those settings so here they are setup like you find them by default.
It's interesting that on your latest plots, you now have flat response or quite so...
But, hey, the point that you don't see any level changes while tweaking the input level know on your decks is WEIRD... actually, here, input level knobs do definitely influence the measured level.

 

[George S.]

No luck using Creative ASIO drivers when doing Software Defined Radio, or Asus ASIO drivers with measurement software. Causes instability in the programs and Windows. These ASIO drivers are a component of the normal windows driver download from the manufacturer, but not included if I just plug in the device and allow Windows to load the driver. A fresh install of Windows, and just plugging in the device and allowing Windows to find and install the driver works best for me. Fresh installs of Windows is fast and easy because I use dedicated machines for this. Windows install media is on a flash drive, and I use a SSD boot drive for Windows only. Fast installation. Anything else I want to keep on the machines is on older mechanical drives in the same machine. I try to keep it simple.

 

[Alex SE]

Well, after that I spent whole afternoon testing drivers and software, both REW and Audio Tester are working with ASIO. Strange things that I can not explain happened under adjustments which included restarting computer, installing and uninstalling REW and ASIO4ALL. Have even found some ASIO from Creative v.1.0.3 (only one that can be found on the internet). At the end, both REW and AT could see ASIO.
Don't know what to say, I feel that non of those measurements can be trusted. The best would be to have real oscilloscope and real tone generator, but it's far away from reality. I mean, those two would cost 400-500 or maybe even more, for what? Couple of decks that are worth equal? Don't think so.
For now I'm tiered of thinking and trying different things. I guess I'll leave decks as they are. Somehow I think that decks are as they should be, it's a soundcard that makes a problems.

 

[George S.]

I agree with all you have said. If you decide to try again, ditch the ASIO, stick with bare minimum Windows drivers.

 

[Alex SE]

To be honest, I wasn't even know about ASIO until couple of months ago. Probably because I'm no longer interested for computers as I was before. Music, movies and games sounds OK, so there was no reason to try to make it better. Somebody wrote somewhere that PC sounds best with ASIO (?!) and if the one want to use a PC as a music source for recording tapes, the one should go for ASIO. As I remember, it was that WASAPI is best. Who knows...

 

[vince666]

actually, i use ASIO drivers since about year 2001, on the soundcard and software which support them properly.... BUT because i need low latency i.e. while playing/recording instruments on a multitrack/virtual-recording-studio software (i.e. Cubase).

of course, if i play a song with windows media player, it will use the windows drivers not the ASIO.

as they rightly say in that description you shared, the ASIO drivers bypass the operating system and give the audio software a direct control on the soundard to just be able to have low latency.... that's the actual/main reason of using them.

 

[Alex SE]

Thanx Vince for sharing information. So, you mean that, when music is played on a PC, there should be no difference between ASIO and Win drivers? How about for testing/measuring purpose?

 

[vince666]

Thanx Vince for sharing information. So, you mean that, when music is played on a PC, there should be no difference between ASIO and Win drivers? How about for testing/measuring purpose?

in theory, it should be no difference in sound.
but, for sure, the ability of getting also low latency (which is mandatory while running music production software) is heavily influenced by the drivers of choice.

anyways, if we can choose the ASIO drivers (and they work fine with the software of choice) , we automatically know that the software will get direct control on the soundcard without relying on the windows system.
But i don't know (never tested it) if there might be any noticeable difference while making measurements.
Audiotester, for sure, is a software which works fine with ASIO drivers... I always used it like that.

 

[laatsch55]

Are you guys aware of Daqarta?

 

[Alex SE]

Thanx for that, haven seen it before. 30$ version should do a job. Will try it as soon I find some time (weekend?). If it works, I'll buy license.
One more thing came to my mind - maybe my card is damaged?! Best way to check it?

 

[laatsch55]

Wrong guy to ask..start talking computer shit, I'm lost..

 

[Alex SE]

Wrong guy to ask..start talking computer shit, I'm lost..

What I mean, card seems to work normal, but sometimes, I do a same sweep test 2 times (repeating), and I have different results. Sounds crazy, doesn't it?

 

[laatsch55]

Yeah, THE MOST FRUSTRATING PART OF TESTING, not being able to have consistent , repeatable results.

 

[Alex SE]

I have on the motherboard integrated soundcard that I never used (until now) so I have tested two combinations. Output from external card and input from internal. Results are the same. Second alternative out from internal card and input from external. Results are same again. So "default" external card seems to be just good. Mystery with card is solved now. As I mentioned, second deck is showing the same results so it sounds almost impossible that two same decks have a same problem.
As someone mentioned, it can be something with resistance mismatch and right now I can't imagine anything else.

 

[vince666]

but resuming....

the decks sound fine and your issues are due to the measurements/soundcard only?

if so, i'd say it's much better than getting perfect measurements while the decks are sounding like crap.

doesn't it?

 

[Alex SE]

OK Vince, I wanted to adjusted overall gain (rec gain), and measuring result made me disappointed (read shocked). Wanted to compare source vs tape and source was bad to as you could se on picture. So, deck doesn't recording bad, signal thru a deck i bad. Then I measured 727 which gave noticeable better result. Then I tested the other 965 and it looks about the same as first one.
I was wondering if there is something bad with 965 decks and then sound card came in picture. As I said, after couple of different ways, conclusion is that it can be something with resistance mismatch. Don't know. Will leave it on the side for now.
Next thing to do is to move those 5 hot transistors to a separate PCB, of course with mounted heatsinks and newly made holders (it have to look as nice as possible). Then, I'll be back to some other things. Point is to make everything perfect I'll upload pictures when everything is done.

 

[vince666]

But, the (possibly) resistance mismatch issue and the obvious differences you can measure on the 965 and 727 happen only while connecting the decks to the soundcard for measurement purposes or do they also show that kind of different behaviour on bass also while the deck is connected to the amplifier while using it?

I ask it just to figure out if yours is only a measurement problem or if you also have a proper performance problem while actually using the decks.
As just told above, it's better to have a measurement problem than to have an actual performance problem.
But I perfectly agree with you that it's just annoying to not get the measurements right... for sure, I wouldn't be happy at all if that happens to me.

 

[Alex SE]

So moving those 5 hot transistors if done, and so long temperature is lower, perhaps because of new (hand made) heat sinks.


Next thing to do is to adjust peak meters and output level.

Now question for those who know:
How resistance is calculated? When peaks are att 0db there should be 400mV on the output but it is 365mV. There is a 100K resistor at the output (se a picture below), and I guess that it should be mat be say 110K?! but is there a formula to calculate exact value of resistor needed?

 

[vince666]

i am not that expert on this, but why changing resistors at output?
can't you do something directly at the meters, where your problem actually is?

and, why don't you check levels at dolby chips, where it's more important that it's the right one?

nice solution for those heatsinks, as those transistors don't have a hole for the screw.