Royd A7 crossover refurbishment.

[brian2957]

I recently bought a pair of Royd A7 speakers off Ebay . I put them into my system for a couple of days to loosen them up . However even after this time they tend to sound a little ' shrill ' in the treble. Bearing in mind that these speakers are probably 30 years old I was wondering if it would be worth replacing the capacitors and the resistor in the crossover .
Value of the 2 caps are : 10mfd 50wv (bi-polar )
3.3mfd 50wv (bi-polar ).
Both are made by a company called Bennic.
Value of resistor is 5w 2.7 ohms +/_ 5%.
Can anybody suggest a suitable replacement for these parts and where I can buy them please . Any help appreciated.
Thanks ,
Brian.

[DSJR]

The A7's and other early Royds were designed for the vinyl era, and a very specific type of buyer. The cartridges we often sold at this level had a very down-tilted response and the extra sharpness of balance on speakers like these (and the Ssssssssintra in particular - ugh!) was deliberate, adding more sparkle to a dull source.

Upgrading the caps to Ansar polypropylenes or similar may well make a beneficial difference - some pics would be nice to ascertain what "type" of caps were used then - can't remember if the Bennics were electrolytic or not. No need to spend a fortune, but if you sensitively breathe on them and use them close to a wall on high stands, the shrillness should subside somewhat and be replaced with a lively engaging tone instead..

Good luck.

[brian2957]

Thanks Dave . I'm using a computer file-based /Dac at the moment and did suspect that this may be part of the problem . The stands are Atacama and are 22 inches high incidentally and they are app. 5 inches from a wall. I read somewhere that crossover components can become less effective over a period of time and may benefit from replacing.. I also wondered if changing the values slightly might 'tame ' things down a bit. Thanks for your help .
Brian.

[DSJR]

Is there an inline tweeter resistor? Adding half an ohm wouldn't hurt (or fitting one of not there) may tame any excessive sparkle. If the issue is more with upper midrange, then I don't know, as fitting a random 100 ohm resistor across the bass coil may or may not take some of the upper mid excess off. Other values may be needed and an understanding of the crossover used and the maths involved is essential to get the correct "flavour" for the drivers, inductor and overall loading.

Sorry to sound so vague, but if they didn't cost you much I'd probably sell them on to keen Royd fans and look for summat a bit more natural in balance - plenty of KEF Coda's about for instance, and Celestion Ditton 100, 110, DL4, DL8 and even some of the Wharfedale Diamond series for smooth sounding miniatures..

[brian2957]

Photo of crossover here Dave

[brian2957]

Is there an inline tweeter resistor? Adding half an ohm wouldn't hurt (or fitting one of not there) may tame any excessive sparkle. If the issue is more with upper midrange, then I don't know, as fitting a random 100 ohm resistor across the bass coil may or may not take some of the upper mid excess off. Other values may be needed and an understanding of the crossover used and the maths involved is essential to get the correct "flavour" for the drivers, inductor and overall loading.

Sorry to sound so vague, but if they didn't cost you much I'd probably sell them on to keen Royd fans and look for summat a bit more natural in balance - plenty of KEF Coda's about for instance, and Celestion Ditton 100, 110, DL4, DL8 and even some of the Wharfedale Diamond series for smooth sounding miniatures..
Problem is I am a Royd fan . I was using a pair of A7s (pre computer / DAC ) but they were lying up in the loft for a couple of years needing a re-foam When these came up at the right price I jumped at them . I took the crossovers out if the old A7s and will try to refurb these .If it doesn't work I will replace the old crossovers . I would really like to make these useable . If not I will let somebody else get the use of them .
Thanks
Brian.

[Reid Malenfant]

Hi Brian, bit of a simple crossover :eyebrows: Looks like the bass/mid is simply allowed to roll off naturally as there are no visble components feeding it :scratch:

You should be able to find some MKT or similar film type caps to replace both of those without too much bother. I'd change the power resistor to something like 3.9 ohms as the caps will have a lower ESR & will be a little more efficient, read brighter.

I'd also connect a 39 ohm 5 - 10W power resistor from the output of the 3.3uf feeding the tweeter to ground. This will supply some damping to the tweeter which it doesn't have right now. Effectively there is a bit of a tuned circuit between the 3.3uf capacitor & the inductance of the tweeter voicecoil. Connecting a resistor directly accross the tweeter should kill a lot of sibilance due to the tendency for these two to oscillate a bit :)

[brian2957]

Hi Brian, bit of a simple crossover :eyebrows: Looks like the bass/mid is simply allowed to roll off naturally as there are no visble components feeding it :scratch:

You should be able to find some MKT or similar film type caps to replace both of those without too much bother. I'd change the power resistor to something like 3.9 ohms as the caps will have a lower ESR & will be a little more efficient, read brighter.

I'd also connect a 39 ohm 5 - 10W power resistor from the output of the 3.3uf feeding the tweeter to ground. This will supply some damping to the tweeter which it doesn't have right now. Effectively there is a bit of a tuned circuit between the 3.3uf capacitor & the inductance of the tweeter voicecoil. Connecting a resistor directly accross the tweeter should kill a lot of sibilance due to the tendency for these two to oscillate a bit :)
Thanks Mark , I understand most of what you have written . Do I connect the 39 ohm 5 w power resistor from the 3.3 uf capacitor to the ground terminal on the tweeter or somewhere else. If its the tweeter which terminal is ground . What value of resistor would you suggest to connect directly across the tweeter mate.
Sorry for my ignorance but I'm probably 'simpler' than the crossover when it comes to electronics. Got to start somewhere I suppose.
Thanks for your help.
Brian.

[Reid Malenfant]

This should explain things better than words :)

6058

[brian2957]

That's the one Mark . I prefer pictures myself . Much easier to ' read ':mental::D
Many thanks again ,
Brian