Recent content by ludo

Still alive sir. Sending you a PM

I also notice that one can no longer see these posts unless one registers and logs in. I don't like that. My contributions here may not have been groundbreaking but I like to think they were sometimes useful to members and non-members alike. I posted them for the benefit of both and don't see...

I notice now that the phono opamp already has 100uF caps on the power pins :geek:

Couple of things that are pretty easy, and that you should hear. Preamp My vote for NE5532s also. 4558 has it's place but not here. I also see that each opamp's supply pin is being fed via a 100 Ohm resistor without any further caps to bypass the rails for the opamp. This is a damned fool's...

If the source selection works then the IC is most likely still just fine. They tend to let nothing through if they get damaged. Sanyo makes three types of this chip, each with different functionality. They're not uncommon. You even see them in mini-hifis. They are not perfect, but they work...

The source selector is actually one of those Sanyo ICs, not a set of relays or mechanical switches. Only the CD input bypasses this IC (and only if CD Direct is enabled) So the relays do further switching. That Sanyo IC is where lightning strikes like to barge in and make itself unwelcome by...

Here's a block diagram of the amp showing the signal switching. The signal switches are all relays, not mechanical switches as the diagram might suggest. With the exception of the Mute relay, all of them are common to any signal the amp passes and can cause a signal dropout. So if one is...

Many moons ago I ran into something like this with a NAD 304, and then again with another one. So maybe this one has a similar problem, seeing as the circuit appears to be pretty much identical in the 314. If you like soldering you might try this, otherwise just mention it to Nilam. In the...

Some possibly useful info about gas geysers. I maintain 4 of them on a smallholding. Out here in the sticks there is no insurance and consequently no installation standards. Of course, if you want your insurance premiums to mean anything you need a certified installer to do the job with a brick...

Before you touch the pots, there is a 47uF cap on the laser supply that goes vrot with these laser mechanisms. I think it sits under the transport. It is probably the one that connects to pin 17 of the TDA8808 IC. My schematic is quite fuzzy but it could be C112. Replace that (and maybe sommer...

Hi folks. It's been a while  :) There was a time when I thought the SR850 is the best bang for the buck headphone ever made. Seriously. It's not perfect but it has tremendous potential. So I would be very happy to fix them for you. I'm guessing yours also have the screw-on adaptor from 3.5mm...

If using a pair of 1N4148s in place of D408 you could place a resistor in parallel to one of the pair. 100 Ohm or so could be a good start. You can still trim bias on R462 then. 1N4007 used at low current (~9mA here) might already  give lower Vf than 1N4148 and be easier to insulate and mount...

There seems to have been some variety in the arms/headshells/carts used on that model. This one is obviously very different https://www.lpgear.com/product/KENWKD0022R.html This type of headshell may be a useful addition as it allows using other 1/2" carts...

Sub-genius input: Q409 cascodes Q407. By having Q409 collector fed from the Voltage amp stage it must have a sort of feedback effect as well. This will be a minor effect though, as current changes in Q407 will be small. Could be worth simulating to see what exactly is going on there, especially...

The IRFP244 will work just fine. The higher VDS variety of a particular part (ie IRFx244 vs more common IRFx240) usually have somewhat higher on resistance. Seeing as the P channel has more than twice the on resistance than the N channel to start with, you can even think of it as an "improved...