found the culprit to the 317 heating up, it was due to c3 tantalum going out which caused a short. This was after replacing the 317 and the gyrator section. Before replacing I checked to see if any of the traces were damaged by using power and following the traces to make sure there was continuity, I wasn't sure of another way but this cam to mine. After this I checked the resistors.
I also didn't know the correct way to test the 317, jfets, and transistor so I replaced them, so I could rule them out. Probably wasted some parts, but at least they're not too expensive to replace.
While testing the traces I saw the tants heating up, after I replaced them everything back to normal except the voltage ouput is still a lilttle to high.
If I feed the op-amps 17volts instead of the 12, what is the result? Is it safe to do so?
I think 17v is still within the operating rage of the lm4562 according to the data sheet.
I also didn't know the correct way to test the 317, jfets, and transistor so I replaced them, so I could rule them out. Probably wasted some parts, but at least they're not too expensive to replace.
While testing the traces I saw the tants heating up, after I replaced them everything back to normal except the voltage ouput is still a lilttle to high.
If I feed the op-amps 17volts instead of the 12, what is the result? Is it safe to do so?
I think 17v is still within the operating rage of the lm4562 according to the data sheet.
Could it be that the polarity of the tantalums is incorrect? Most of them have a (very) small plus-sign printed on the case, or a black stripe to indicate polarity. Sometimes you have to consult the datasheet to be sure. Anyway, the short leg also indicates minus.
Is the output of the LM's ok now? If that is already 17V that means your gyrator is doing nothing because it also outputs 17V. There's not much point in using the Teddy Reg like this.
Look at my previous post:
Ray
Is the output of the LM's ok now? If that is already 17V that means your gyrator is doing nothing because it also outputs 17V. There's not much point in using the Teddy Reg like this.
Look at my previous post:
I'm using this schematic. If the print on the board is different, that sucks. Just to be sure: you're not using a SuperTeddy board, right?
Ok, first make sure the LM reg is outputting 18V. With R1 = 220 ohm and R2 = 3k this should be 18.3V to be exact. With the values for R3 and R4 that you have now, the output voltage should be around 13V then. Make sure R13 = R3 and R14 = R4.
If the output is still 18V, check for proper oriëntation of the transistors and measure the voltage at the junction of R3/R4. This should be 13V. If this is o.k., check the voltage at both sides of R6. This should be around 13V as well.
Ray
Ray
Ray,
my mistake, i looked at my teddy board and the schematic you linked to in your post. The board layout is the same as in the scematic except it does not have r13, r14 and c7.
Malefoda, that's good to hear! I will give it a try.
my mistake, i looked at my teddy board and the schematic you linked to in your post. The board layout is the same as in the scematic except it does not have r13, r14 and c7.
Malefoda, that's good to hear! I will give it a try.
ray,
I'm still getting the same readouts as before, maybe I can try a trimpot to dial in r2?
For some reason, the the voltage is not dividing correctly. There is some dropout but definitely not enough and not according to the resistor values I used.
I'm still getting the same readouts as before, maybe I can try a trimpot to dial in r2?
For some reason, the the voltage is not dividing correctly. There is some dropout but definitely not enough and not according to the resistor values I used.
Ray
just read your post, no its not 18v it's only a volt or so down from the input. So, that means the gyrator is not working. No use in using if can't get it to work correctly.
BTW, whats the best way for testing the adj regs, fets, transistors?
just read your post, no its not 18v it's only a volt or so down from the input. So, that means the gyrator is not working. No use in using if can't get it to work correctly.
BTW, whats the best way for testing the adj regs, fets, transistors?
Well, I would concentrate on the LM regulators first then. Check the values of the resistors. Swap the LM for a new one. Try a load on the output of the regulator, like a 2k2 resistor and see what that does. The circuit is simple: one LM, two resistors and an input voltage 😀
Ray
Ray
Ok, so it's not a stability problem due to the minimum load current. So the LM is still outputting almost the input voltage? Measure the voltage between OUT and ADJ and across the 220R resistor. This should be around 1.25V.
You can read my LM317 tutorial to see how the voltage is set with R1 and R2.
Ray
You can read my LM317 tutorial to see how the voltage is set with R1 and R2.
Ray
That's too high, this means the LM317 is not regulating. Check if R2 is properly connected fron ADJ to ground. I suspect it's "floating" on one side. It's has to be a bad connection, because the LM itself sees to it that there's always 1.25V across R1 resistor. It's either that, or the LM is defective...
Ray
Ray
OK, I did what you adivise Ray, I jumpered the R2 to the adj on the LM on the 337 and volt in is -23.5 and out -18.3 at the LM. Teddy is putting out -14.3v still not quite the 12 but it's getting there.
On the 317, I jumpered also and its input is 23.5v but out on the lm is only 22v. It's alot better but not quite the same as the negteddy. Maybe 317 is bad, I will swap as soon as I get more 317's in. This Teddy is output is 15.7 about 1 volt lower than it use to be.
Question on the cd63, is it safe to remove the 12v regs on q801 and q802 along with its caps if Im gonna use the teddys to power opamps. Or are the stock regs powering anything else on the cdp.
BTW, got the boards yesterday. I'm excited but will play with the teddys powering the opamps to compare with DOS in future. Or just dump the opamps for DOS if I can't get the teddys going for it.
As of the moment I have 5v regs at analog and digital at the dac, servo,decoder. Is it advisable to put 2 teddys one for analog and digital to power all three sections.
Eventually the 2 teddy regs on seperate PSU.
Thanks for your help!
On the 317, I jumpered also and its input is 23.5v but out on the lm is only 22v. It's alot better but not quite the same as the negteddy. Maybe 317 is bad, I will swap as soon as I get more 317's in. This Teddy is output is 15.7 about 1 volt lower than it use to be.
Question on the cd63, is it safe to remove the 12v regs on q801 and q802 along with its caps if Im gonna use the teddys to power opamps. Or are the stock regs powering anything else on the cdp.
BTW, got the boards yesterday. I'm excited but will play with the teddys powering the opamps to compare with DOS in future. Or just dump the opamps for DOS if I can't get the teddys going for it.
As of the moment I have 5v regs at analog and digital at the dac, servo,decoder. Is it advisable to put 2 teddys one for analog and digital to power all three sections.
Eventually the 2 teddy regs on seperate PSU.
Thanks for your help!
That's better! 18.3V is spot-on for your resistor values. So there must be a bad connection or broken track somewhere. The LM317 could be defective, but it could also be that R2 has a bad connection to ground.
Q801 and Q802 can be removed if you're not using them to power the opamps and HDAM section. The muting circuit uses the -12V as well, so this will be disabled. If you have the muting transistors removed, it's already disabled.
Adding extra regulators should bring more improvement, because the circuits get more separated. Things like noise are less likely to travel between circuits via the power lines.
Good to hear your boards arrived o.k.!
Regards,
Ray
Q801 and Q802 can be removed if you're not using them to power the opamps and HDAM section. The muting circuit uses the -12V as well, so this will be disabled. If you have the muting transistors removed, it's already disabled.
Adding extra regulators should bring more improvement, because the circuits get more separated. Things like noise are less likely to travel between circuits via the power lines.
Good to hear your boards arrived o.k.!
Regards,
Ray
For the cd5400, there are many threads about modding.
Use the search function for CD5400
Andy
.
Use the search function for CD5400
Andy
.
With the 6000 rip out those two large smoothers for the +/- 12V and replace with some snap in style caps like the Mundorf SI or our own branded SI cap (same item). Some pcb work is required here but it really does do a good job of bringing in the OTT forward sound.
Also remove the silmics around the dac digital rails and replace with Oscon SEPC. Remove the 4 Silmics at the audio output and replace with a MKP MKT capacitor.
But as Andy says there sould be plenty of threads on these players
Brent
And how about if i also upgrade clock to TCXO and replace HDAM by dual OPA LM-49720HA. Totally it costs around 150USD. Is it good to pay?
Thanks a lot
Thanks a lot
My '67 is really beginning to sing at 150 hours. Thanks Ray and Brent. I'll make a proper report here in a few days. This was a serious upgrade to the old dame! she took it like a trooper (after sulking in the beginning)
just a quick thought: this IS digital; bits...plus/minus etc. The better the source, the more the dots are connected into a seamless whole that sounds like music rather than a synthetic replica. After a long painfull sulk, no doubt due to the new caps, the dots make a very pleasant and convincing analogy. I would say at this level (which is still a ways off from the best one can do with this) i am getting much closer to what i associate with a really got TT rig, at greatly reduced cost. When I think of what I spend in the old days...and I still had to clean the needle every time, fuss and get up to turn over the bloody record. No remote!