ruffrecords

Flickinger 535 op amp schematic
« on: September 14, 2018, 05:06:57 PM »
Anyone got a schematic for the Flickinger 535 op amp? I have scoured the web but cannot seem to find one.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'


Re: Flickinger 535 op amp schematic
« Reply #1 on: September 14, 2018, 05:21:35 PM »
I made this from some photos of an actual card. Can't vouch for it beyond that. Output transistors are a guess, the others come from other Flick cards I've seen.

Note this doesn’t sim properly in LTSpice so it’s not quite right.


« Last Edit: September 14, 2018, 05:39:17 PM by dogears »

ruffrecords

Re: Flickinger 535 op amp schematic
« Reply #2 on: September 14, 2018, 06:28:04 PM »
Thanks for the schematic. Yes, something looks odd around Q4 and Q5.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Flickinger 535 op amp schematic
« Reply #3 on: September 14, 2018, 07:48:45 PM »
there is a schematic in his patent.

for both the -5 and -7 versions,
the output transistors are the 2N2102 / 2N4036 complements.

PRR

Re: Flickinger 535 op amp schematic
« Reply #4 on: September 14, 2018, 09:53:16 PM »
THAT one again?? (Or is this another Flick?)

Every time interest wanes and I archive it, someone stirs it up again.

Re: Flickinger 535 op amp schematic
« Reply #5 on: September 14, 2018, 11:06:37 PM »
The 535 is a later one, I believe.

ruffrecords

Re: Flickinger 535 op amp schematic
« Reply #6 on: September 15, 2018, 04:19:26 AM »
THAT one again?? (Or is this another Flick?)

Every time interest wanes and I archive it, someone stirs it up again.

Someone on another board claimed it was a knock of/improvement of the sound techniques op amp so I wanted to see a schematic to judge for myself. Clearly it is very different.

Cheers

Ian
www.customtubeconsoles.com
https://mark3vtm.blogspot.co.uk/
www.eztubemixer.blogspot.co.uk


'The only people not making mistakes are the people doing nothing'

Re: Flickinger 535 op amp schematic
« Reply #7 on: September 15, 2018, 10:49:01 AM »
Thanks for the schematic. Yes, something looks odd around Q4 and Q5.

Cheers

Ian

Here's what I used. Maybe you can find my goof.





moamps

Re: Flickinger 535 op amp schematic
« Reply #8 on: September 15, 2018, 12:35:32 PM »
Note this doesn’t sim properly in LTSpice so it’s not quite right.

It works in my simple sim.

mjrippe

Re: Flickinger 535 op amp schematic
« Reply #9 on: September 15, 2018, 12:56:48 PM »
Here's what I used. Maybe you can find my goof.



Are you saying there is a goof on the boards you are selling on ebay?
https://tinyurl.com/yajnf9t2


hitchhiker

Re: Flickinger 535 op amp schematic
« Reply #10 on: September 15, 2018, 02:08:59 PM »
Why would he be reverse engineering from pics his own pcb? And be goofing it to boot?


Are you saying there is a goof on the boards you are selling on ebay?
https://tinyurl.com/yajnf9t2

Re: Flickinger 535 op amp schematic
« Reply #11 on: September 15, 2018, 04:12:50 PM »
Those aren’t my boards, those are the ones I made the schematic from. I don’t know what transistors are being used in the clones, and some of the resistor values may be wrong.

Moamps, curious, mind sharing your sim results? When you say it works, in what mode? Inverting or noninverting, how much gain?

moamps

Re: Flickinger 535 op amp schematic
« Reply #12 on: September 15, 2018, 05:05:18 PM »
The program is old Circuitmaker pro.
All resistors as you stated, all NPN are 2n2222, all PNP are 2n2907, noninverting mode,
+in 10k to ground, -in 5k to ground and 50k\\22pF from the output. Gain  is 11.

PRR

Re: Flickinger 535 op amp schematic
« Reply #13 on: September 15, 2018, 05:16:27 PM »
> this doesn’t sim properly

Looks OK at a glance. Can you screen-grab your actual sim plan with a few key node voltages?

Re: Flickinger 535 op amp schematic
« Reply #14 on: September 15, 2018, 05:37:20 PM »
I will when I get a chance, out of town tonight.

When I did this, if I remember, it wasn’t unity gain stable (wasn’t expecting it to be) but I recall adding some gain. I figured maybe my transistor guesses were off, or maybe my pinouts were.

mjrippe

Re: Flickinger 535 op amp schematic
« Reply #15 on: September 16, 2018, 12:58:13 PM »
Why would he be reverse engineering from pics his own pcb? And be goofing it to boot?

Misunderstood that he was reversing from these - thought they were his build and he was asking us to find the error! My bad!  :-[

Re: Flickinger 535 op amp schematic
« Reply #16 on: September 16, 2018, 07:34:50 PM »
Found my mistake in the simulation - I had the 51R and 3K base and emitter resistor values under Q6 reversed in my simulation.

However, with the transistors I had (2N5210 and 2N5087 with BD237/8 output) it was no bueno. Using 2N2222 and 2N2907 cleared it up. But I was guessing on the transistors from this earlier post.



Here's OLG and phase



Anyone have any idea what the originals were? The earlier ones were TI epoxy type with what looks like a 2N4036/7 output pair?

« Last Edit: September 16, 2018, 07:41:42 PM by dogears »

PRR

Re: Flickinger 535 op amp schematic
« Reply #17 on: September 16, 2018, 08:09:53 PM »
> with the transistors I had (2N5210 and 2N5087 with BD237/8 output) it was no bueno.

If you get the NPN/PNP polarities right, it will not matter what the transistor types are. High-hFE parts will give a lower THD number, but it will bias-up and pass clean audio with (NPN/PNP-sorted) scruff from old Sansui hi-fis.

PRR

Re: Flickinger 535 op amp schematic
« Reply #18 on: September 16, 2018, 08:22:20 PM »
BTW: in SPICE it is not generally necessary to put decoupling caps on voltage sources. Unless you have an internal series resistance the output impedance of a Voltage Source is ZERO.

However when you set-off from there with those 10 Ohm resistors, you SHOULD have a decoupling cap to hold-down the far end of the series resistance against the heavy sloshing from the output stage.

(In _this_ case, in SPICE, everything is balanced and there may be little ill effect from soft rails. But if you see such things at a glance you may not need SPICE anyway....)

Re: Flickinger 535 op amp schematic
« Reply #19 on: September 16, 2018, 08:33:51 PM »
> with the transistors I had (2N5210 and 2N5087 with BD237/8 output) it was no bueno.

If you get the NPN/PNP polarities right, it will not matter what the transistor types are. High-hFE parts will give a lower THD number, but it will bias-up and pass clean audio with (NPN/PNP-sorted) scruff from old Sansui hi-fis.

I thought so to, so maybe it has to do with the model that is being used. But I checked the NPN/PNP and one oscillates quite a bit more than the other. I’d assume if I had the type backwards it wouldn’t reproduce the input waveform at all.

Thanks for the bit about the cap - I usually don’t include them in LTSpice but in this case I did. I see your point about the resistance.


 

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