I don't know how many units were sampled to draw this conclusion, but it can also be as simple as manufacturing/assembly tolerances. IOW, a static issue. Everyone I know who cuts or embosses directly on these units does a one-time shim, if needed, on their cutting mat (usually vacuum) to true it up and that holds tolerance without issue, which is a lot tighter than what would be needed for playback in consideration of how variable the records themselves are.
Is there a block diagram or some "high level" description of how the SP-10 drive electronics works? I saw a schematic years ago but it was a lot of transistors with little or no description of what does what, much less how or why. Perhaps I could look again and study it more intently.
I've had my ideas of what a three-phase DD drive system should do, and wanted to use this on a SL-1xxx series TT. I wrote about it on diyaudio many years ago but haven't done anything with it.
thank you very much but unfortunately last week the old man who did some precision work on the lathe died and for now I don't know others, also because the turners are difficult to find in my area and if they are found or they don't accept the commission or ask for an exaggerated price. 😢
No, the block diagrams in the manual just show the different functions of each circuit. With experience looking at the diagram and circuit you can get a good idea of how the SP10mk2 operates. The engineering is very good even by today's standards.
Research Gate has quite a lot of information on FOC. One I read from NASA is what spurred me to investigate this type of motor control for the SP10. It's quite a sophisticated control topology and I'm certain it's capable of improving dynamic speed stability of the mk2 motor.
To answer your question, in the context of a deterministic, linear, time invariant system, the impulse response contains all the necessary and sufficient information to re-construct the output for ANY desired input. Such outputs are the time convolution of the input with the impulse response. That is the whole point. In the frequency domain the system transfer function is the Fourier transform of the impulse response.
Naturally an impulsive input is an idealisation, but in practice can be sufficiently well approximated to provide relevant data. It is a highly developed technique in reflection seismology to investigate subsurface geological features.
I am pretty certain this reply will not satisfy you, but anyone else who is interested in my bona fides, is welcome to privately message me.
Actually, FOC was exactly what I was thinking of, and I was wondering if that's what all that circuitry does.
@benb FOC is a sophisticated uC, no analog controller will be capable of this level of control. uC are not my area of expertise, I have a friend who has worked in the uC PID area for 40years and I'll be utilising his input to assist with this project. He's already given me the uC and some libraries to play with but I've been busy with the inverted bearing upgrade. Once this is done I'll make a start.
SP-10MK2A service manual page 5 has a very high level description. SP-10MKII service manual block diagrams are actually rather illuminating once armed with the general overview. SP-10MK2A service manual page 18 has a rather detailed block diagram. It's circuit-centric but calls out the important bits. SP-15 service manual page 13/14 has a moderate level block diagram. Ignore the MN6042 section as the SP-10 doesn't have pitch control.
SP-15 and SP-10MK2A are LSI but the the operating principals and methods are the same.
There are a few here that know it well including at least one that has built a motor control so I think most questions could be answered.
Since I first was informed of the service being considered as shown in the link, I have encouraged it to become more established.
I am now informed there is a established service in place, and it is ripe to receive inquiries on other products to be produced, which I have already commenced with .
I hope this enables others to venture into experiencing the use of Densified Wood with less constraints and concerns put in the way, to those that could usually be met.
I am looking forward to see how the offers increase as a result of creative types making their inquiries.
https://www.lencoheaven.net/forum/index.php?topic=42484.0
I am now informed there is a established service in place, and it is ripe to receive inquiries on other products to be produced, which I have already commenced with .
I hope this enables others to venture into experiencing the use of Densified Wood with less constraints and concerns put in the way, to those that could usually be met.
I am looking forward to see how the offers increase as a result of creative types making their inquiries.
https://www.lencoheaven.net/forum/index.php?topic=42484.0
As I have now discovered somebody I can communicate with directly about having Densified Wood produced. I have made an inquiry about a particular board design I am interested in, which has the Plies Configured with additional cross grain that is not limited to 90 Degrees.
I have been assured by the supplier shown in the previous mails link, that the production spec' for the EV6 Material that is being offered, has the Plies overlayed to have a cross grain that is not limited to, but has layers where then grain is orientated to be less than 90 Degrees.
My attraction to this type of structure has been to have a material that conforms to typical Phenolic Densified Wood Properties, but create a material that offers structure that applies itself to increase on how it can dissipate transferred energy.
I have been assured by the supplier shown in the previous mails link, that the production spec' for the EV6 Material that is being offered, has the Plies overlayed to have a cross grain that is not limited to, but has layers where then grain is orientated to be less than 90 Degrees.
My attraction to this type of structure has been to have a material that conforms to typical Phenolic Densified Wood Properties, but create a material that offers structure that applies itself to increase on how it can dissipate transferred energy.
Hi, does anyone have an idea with what equivalence to replace the 2SD289A transistor fixed on the aluminum panel in the power supply SH10E without making any circuit changes or other parts replacement?
Thanks
Thanks
This should do the job.. It's really difficult ATM as a lot of transistors are nil stock as RS
https://au.rs-online.com/web/p/bipolar-transistors/8070906
https://au.rs-online.com/web/p/bipolar-transistors/8070906
@warrion @ralphcooke many thanks.
I have a power supply that has several components replaced by the previous owner (capacitors with higher capacities) and I also found a 2SC2336 instead of the 2SD389A but it has too low values as collector current, also emitter/base voltage is lower and also of power dissipation and I would like to put everything back as it was originally.
Can the 2SC2336 transistor remain fixed in its place having several lower parameters or better switch to the equivalences indicated by you?
I have a power supply that has several components replaced by the previous owner (capacitors with higher capacities) and I also found a 2SC2336 instead of the 2SD389A but it has too low values as collector current, also emitter/base voltage is lower and also of power dissipation and I would like to put everything back as it was originally.
Can the 2SC2336 transistor remain fixed in its place having several lower parameters or better switch to the equivalences indicated by you?
I had a look at Mouser, the TIP41c seems to come closest, and is most likely available almost everywhere
It is also available from RS-online. The transistor identified by Warrjon, a FJPF13007H2TU will also do the job,
but I don't think you need a 400V device. 🙂
It is also available from RS-online. The transistor identified by Warrjon, a FJPF13007H2TU will also do the job,
but I don't think you need a 400V device. 🙂
Correction Required:
The Supplier has contacted me to make it known the EV6 Material has a Cross Grain Structure that has the Plies orientated at 90 Degrees only.
This competes with the typically available structure of other Brands Boards and is the most desired for a boards structure when used for the purposes discussed within this thread.
I have a Mk3 in a custom plinth. The plinth is roughly of the same size and dimensions as most that one sees.
I am seeking a maker of the flat-type dust covers. Probably don't need anything custom-designed....I suspect any that fit the usual Mk3 plinth tables will suit me as well. Just need a quality source.
I am seeking a maker of the flat-type dust covers. Probably don't need anything custom-designed....I suspect any that fit the usual Mk3 plinth tables will suit me as well. Just need a quality source.
