Mea culpa!
The hum was caused by interconnects being too near speaker cables.
Mea culpa!
The hum was caused by interconnects being too near speaker cables.
Current: [P20] Roon/Tidal > Custom PC> Chevron Paradox NDF16 > Phast Pre > Neuro. 686 > Tannoy Berkley (RFC tweaks)
Perhaps a loose connection at rear of amp. I 'jiggled' (well known technical term ) the wires at rear of amp, hum went and I assumed speakers cables lying too close to interconnects.
Anyway now switched over amps. This time to Tom's Valeb Nelson Pass inspired 20w amp. Beautiful textured liquidity with rich midband and open top. Slightly less bass slam but still palpable.
Current: [P20] Roon/Tidal > Custom PC> Chevron Paradox NDF16 > Phast Pre > Neuro. 686 > Tannoy Berkley (RFC tweaks)
I once isolated a hum caused by a 2mm exposed wire picking up transformer hum. "Flying leads' solved this.
Chris.
Hi Edward, here's the info on shorting out the treble energy and roll-off switches.
Something to note: this is only applicable to treble energy-1 setting (which I like best) and roll off setting at level. If you attempt this procedure you should set the switches to these positions before you start and not move them again while the links are in place as although shorted out the switches are still connected and moving them will create a parallel circuit which the crossovers or drivers were not designed for and may cause damage.
Three links are required per crossover (the ones with the red lines, ignore other grey cables)which relate to the three pairs of coloured dots on the schematic below. I've put a note to say that there's no connection to the track just above the left hand link as it looks very close on the photo.
P.S. I came up with this myself so do so at your own risk!!
Wow John, thanks very much for this. Looks simple enough. Yes running a parallel circuit is not ideal. If I were to do this I probably would disengage the switches from their spindles (somehow) to remove the risk.
I do hope you already had the pictures available and did not open up your cabs just for me. But if you did a double thanks!
Up to today I've driving the Berkeleys with other amps as my Radford STA25 was out on loan. But now back in and boy do the Berkeleys rock.
I'm gonna miss them when I do the cab restore and xover recap.
Current: [P20] Roon/Tidal > Custom PC> Chevron Paradox NDF16 > Phast Pre > Neuro. 686 > Tannoy Berkley (RFC tweaks)
No problem Edward. My crossovers are in a state of flux (literally) at the moment as I am experimenting with different capacitors and are actually sitting on top of my cabs with massive Mundorf Supremes hanging from them so photos weren't a problem. There are definitely transparency gains to be had with new caps and the biggest difference you will notice is the stereo imaging will come into focus massively compared to the old caps. These drivers can do pinpoint placement of instruments in a big soundstage. It's now one of my favourite attributes of these great speakers.
They can sound dynamically flat with an amplifier with too high a damping factor. The Radford is probably ideal in this regard, not too high, not too low.
Could I ask you for a favour?
Would you measure the bass port diameter and length please and let me know?
Thanks
Diameter is 7cm and length is 12cm (which includes ~0.5cm baffle thickness).
Oh you are in the midst of a recap - how handy!
Yes instrument placement precision is up there in terms of what I listen out for. Makes for a very involving and 'there' sound.
Are you just doing caps or also looking at resistors? I've not done resistors in the past.
Would love to see your parts list. I had imagined going with the ClarityCap ESA range but perhaps your choice is better?
Feel free to take it to PM if you wish.
Current: [P20] Roon/Tidal > Custom PC> Chevron Paradox NDF16 > Phast Pre > Neuro. 686 > Tannoy Berkley (RFC tweaks)