I upgraded my pair of SA/1's with four 100,000uF, 100V CDE caps per chassis.
Regarding driving the Kappa 9. In my second setup (for the wife) I run a set of Kappa 9's with a old Threshold Stasis 3 amp. My wife likes to dance with disco SPL's (not with disco music though) and the power is sufficient. I find that a incredible performance by the Stasis 3.
Regarding driving the Kappa 9. In my second setup (for the wife) I run a set of Kappa 9's with a old Threshold Stasis 3 amp. My wife likes to dance with disco SPL's (not with disco music though) and the power is sufficient. I find that a incredible performance by the Stasis 3.
The Stasis 3 (according to the German Audio Magazine 'Hifi Exklusiv' 2 x 163Watts @8Ohms and 2 x 233 Watts@4 Ohms) did not fair so good with the Watkins woofer on my QLS. It became too hot to touch and blew a 5 amp railfuse.
Nice feature was that all the LEDS on the failing channel became stationary
The SA/1's have no problem whatsoever with the Infinity QLS's even fullrange.
Maybe the first incarnation Stasis amps (Stasis 1, 2 and 3) do not fair well with these loads?
Nice feature was that all the LEDS on the failing channel became stationary
The SA/1's have no problem whatsoever with the Infinity QLS's even fullrange.
Maybe the first incarnation Stasis amps (Stasis 1, 2 and 3) do not fair well with these loads?
On the topic of 12e, my right channel has developed some noise. A hum which does not seem to be mechanical as I can hear it on the speaker (IRS Beta). I will try disconnecting the Servo Control cable to see if its the Servo injecting noise.
Now, my amps dont get warm at all, let alone hot, I wish I could tune them up myself or locally (South Florida) since shipping them is prohibitive.
Now, my amps dont get warm at all, let alone hot, I wish I could tune them up myself or locally (South Florida) since shipping them is prohibitive.
Also interested in finding a quality service provider for high end gear here in South Florida. Any suggestions would be welcome.
In the case of the hum, check the DC offset to be sure it is happy. It should be less than say 100mv. This means checking the voltage with a multimeter in DC across the + and - binding posts. If the DC offset is high, seek service. I do not believe there is an adjustment for it.
The bias is not normally hard to adjust on these amps. On the S series, you turn a bias pot (which can be sensitive as it is a single turn pot) while reading the voltage drop across any of the emitter resistors. Increase the voltage drop across the emitter resistor in 5% increments with the bias pot. The heatsinks should be between 45C-50C. You will want to place the cover back on every time you make an adjustment and let the amp adjust to it's new temperature (takes about 1/2 hour). When you get it pretty much nailed down, check it after a couple of hours.
I do not know what the actual spec is but you should see something like 50mv-120mv voltage drop accross a emitter resistor if they are 1 ohm resistors. So if you have a reading of 45mv, inrease it to say 48mv-50mv and watch the temps.
On the S series, you remove the back cover to access the pot.
A good person to message for more biasing details would be Jon Soderberg of Vintage Amp Repair. Attached is the E series schematic.
I know Epic audio in Naples FL does some servicing. I don't know where you are in FL but you could give them a call.
The bias is not normally hard to adjust on these amps. On the S series, you turn a bias pot (which can be sensitive as it is a single turn pot) while reading the voltage drop across any of the emitter resistors. Increase the voltage drop across the emitter resistor in 5% increments with the bias pot. The heatsinks should be between 45C-50C. You will want to place the cover back on every time you make an adjustment and let the amp adjust to it's new temperature (takes about 1/2 hour). When you get it pretty much nailed down, check it after a couple of hours.
I do not know what the actual spec is but you should see something like 50mv-120mv voltage drop accross a emitter resistor if they are 1 ohm resistors. So if you have a reading of 45mv, inrease it to say 48mv-50mv and watch the temps.
On the S series, you remove the back cover to access the pot.
A good person to message for more biasing details would be Jon Soderberg of Vintage Amp Repair. Attached is the E series schematic.
I know Epic audio in Naples FL does some servicing. I don't know where you are in FL but you could give them a call.
I remember hearing a pair of QLS speakers in the 70s. They were playing some pipe organ music and also some of Joni Mitchell's Don Juan's Reckless Daughter with Jaco Pastorius doing his thing. This system produced some of the deepest, loudest bass I've heard before or since. This defined "pants-fluttering" bass for me. The dealer said they weren't adjusted quite right, but they sounded amazing. The amplifier was a GAS Ampzilla II, IIRC.
I am in greater Fort Lauderdale so Naples is not a bad drive! Thanks for the info.
I have a Zen Line Conditioner (Decware) with the optional DC filter. Still have the noise.
Nailzgun, see recommendation above! There is a shop in Boca which I am going to try with my DAT Deck (Stereo Fixers).
What are you trying to get fixed?
Check your dc offset. It is simple and invaluable to know. The dc offset is what is going out of the speaker terminals, not what is going into the Amplifier
That is not too far off. The idea is around 25C above room temperature. So if your room is say 75 degrees Fahrenheit, then you would want to set your amp for around 49. Realistically, somewhere between 45-50.
Yeah, feel free to ask any questions. Once you track down the pot, make sure there is only one (which I believe there should be). Also, make sure there is nothing connected as you do it. The big thing is making sure you know what the emitter resistor is and how to measure the voltage drop across it (not hard)
I'll come back here when I feel confident enough to open it up.....
Accountant playing as electronic tech!
Accountant playing as electronic tech!
Hello everyone. I would like to clarify some doubts I have about the Threshold SA12E diagram.
In the universal FEB schematic:
-Where is the cathode of the diode in U1 (CNY17-3) connected?
-Are the thermistors NTC or PTC?
-Which of the three thermistors is connected to the heatsink?
-In transistors Q14-Q15: Where are their collectors connected?
-Where are the emitters of transistors Q1-Q2 (-7V, +7V REG OUTs) connected?
Thanks in advance to all those knowledgeable in the matter willing to help. Blessings.
In the universal FEB schematic:
-Where is the cathode of the diode in U1 (CNY17-3) connected?
-Are the thermistors NTC or PTC?
-Which of the three thermistors is connected to the heatsink?
-In transistors Q14-Q15: Where are their collectors connected?
-Where are the emitters of transistors Q1-Q2 (-7V, +7V REG OUTs) connected?
Thanks in advance to all those knowledgeable in the matter willing to help. Blessings.