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Wakefield Turntables
20-10-2018, 19:55
I want to add a little more flexibility to my cartridge loading on my MM 834 clone and I decided that I want to try and control the loading capacitance of the cartridge. I may want to play around with other cables etc at some point in the future. Ideally I'd like to be able to select very small increments and if entirely possible see a visual reading maybe a numerical display. So my question is, how is this best implemented? I'm happy to spend money on good quality components.

sq225917
20-10-2018, 20:15
More than the stage cost. Unless you're happy with a Chinese 24 position switch and a dial display.

Easiest way to do it would be a set of two pin pcb sockets on flying leads. Then just screw different caps in. Or build in a pair of 4ca sockets just for cap loading. That's an easy job


Do you want to mess about repeatedly or find the best value for a specific cart?

Wakefield Turntables
20-10-2018, 20:30
Thanks for the speedy reply.

Wakefield Turntables
21-10-2018, 19:06
Do you want to mess about repeatedly or find the best value for a specific cart?

No I want a simple rotary switch on the front of the phonostage fascia which outputs capacitance to a simple dial display that way I can visually see what capacitance has been selected. This saves having to mess around making decals for differing values on the front of the phonostage fascia.

YNWaN
22-10-2018, 03:13
It all boils down to the age old conundrum, do you want convenience or quality.... because the two are, to a point, mutaly exclusive.

Primalsea
22-10-2018, 07:32
I think that if you wanted a front-viewed switch and somewhat better quality you would have to mount the switch (switches for both channels would be better) at the back of the phono stage, close to the input sockets and use extension bars so that the knobs can be mounted on the front fascia.

sq225917
22-10-2018, 09:16
Were it my delicate phono signal i'd want the shortest wiring path possible, so rear mounted switches with extension bars as Paul says would be the way forward. I'd be looking at Elma, Shalco, Seiden or Goldpoint selector switches and styrene caps. Getting the display dial for the front is the tricky part, that's full-on custom work.

For me the sweet spot in terms of switch quality, size, number of positions and price is the Goldpoint single deck 12 way. http://www.goldpt.com/selector.html

bbbiker800
22-10-2018, 11:58
No I want a simple rotary switch on the front of the phonostage fascia which outputs capacitance to a simple dial display that way I can visually see what capacitance has been selected. This saves having to mess around making decals for differing values on the front of the phonostage fascia.

The Lounge Audio Copla provides that I think but only for MC cartridges. Regards Richard

disarmamant
22-10-2018, 18:38
I want to add a little more flexibility to my cartridge loading on my MM 834 clone and I decided that I want to try and control the loading capacitance of the cartridge.

You may not be gaining much flexibility, depending on the make of MM cartridge your intending to use. If your 834 valve phono clone uses ECC83’s in the first stage then the loading capacitance is already around 200pf or more just from the Miller capacitance of the high Mu input triodes.

If you factor in the capacitance of the phono cable from the arm to stage it could be already nearing 300pf. Adding more capacitance is unlikely to benefit most modern MM cartridges, such as An Ortofon 2M which expects to see 150pf to 300pf.



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Aerobat
25-10-2018, 15:01
I built my Pearl 2 with adjustable loading and gain. I used Belden Brilliance shielded microphone cable to the switches. Nothing fancy and works well.

https://4xo37g.by.files.1drv.com/y4miIMMkIrvzR19dK4r_J69EF9ABkSlbCt_LCeFowkzjdUr6q0 2ivR2F7HVHYMM8cYNx6krAsvLaFTBbavYtrRtGt5dSGU_aTY3o PdTcwRp_RRWZMqxBklX9gDx1upM98MKu4eojAyABMFhEmy2wlD DO-2X7T0X8jC2-Aq6djO6NkEdXwRfKsE891fRVCZjByGjpmYou5ZizUc9kEgJqhc nuA?width=1024&height=576&cropmode=none

Wakefield Turntables
25-10-2018, 18:40
Ive been offline for 2 days. Will post later lads!