We are extremely busy at the moment - all queries by email please.
We are extremely busy at the moment - all queries by email please.
DRIVE UNITS BY MANUFACTURER:
MCap EVOO-120
Audiophile grade polypropylene / aluminium film in oil capacitor for loudspeaker crossovers. Precision wound core, hand spooled and potted. 3% tolerance.
Smooth but revealing with great transparency - excellent inner detail.
Length: 21mm
Diameter: 30mm
Leadout: 35 / 50mm, 0.8mm wire - shorter lead denotes outer foil.
Part No: EVOO-120
Datasheet:
1990 Linn Index II LS120 Crossover and wiring upgrade.
Truly Outstanding performance upgrade flying in the face of conventional wisdom.
The resistor value is increased from 2.2 to 2.7 and is an official Linn Service 'performance' upgrade.
HF
C1 3.9uF Jantzen Superior z-cap
C3 1uF Mundorf MCap EVO Aluminium Oil
R1 Mundorf M-Resist 5W 2.7 Ohm 2% MOX
LF
C2 5.1 uF split
3.3 uF Mundorf MCap EVO Aluminium Oil
1.8 uF Jantzen Superior z-cap
Carded lambswool replacing original poly wadding. Increased weight replacing 132g ea. for 215g ea. This was weighed out in stages and determined by sonic performance.
Small amount approx 15cm sq of Bitumen foam panel placed in two pieces in base of cab. (leftovers from another project.)
Jantzen solid core speaker cable AWG 17/ 1.15mm stripped of PVC outer sheath to leave only high performance PE insulation. Doubled and twisted Star-Quad. 2.3mm
x2 400mm lengths ea.
Replace binding post steel nuts and locking nuts on back of PCB with copper nuts x8 and locktight. (steel nuts in signal path???= Nuts)
Remove all Plastic front panels and rubber securing bungs. Seal air holes in front baffle sockets. (Holes!)
Total cost £190.00.
Worth every penny! The cost of replicating this level of performance will be many, MANY times this amount. This understanding determined my budget. Happy to spend £200 upgrading on a gamble for the knowledge and experience. The results are very serious for this money.
I purchased these new in 1990 and paid £220.00. They were never highly regarded but always delivered a satisfying sound I never bored of even though Bass is not a strong point in this sealed design. Proximity to rear wall is everything here.
No previous experience with crossover upgrades. Never built a PCB. Very limited knowledge of electronics A beginner !
Every sonic element is vastly improved. Detail everywhere, Soundstage opened up. Depth, Clarity, Definition, Truly remarkable the level of performance these 'nothing special' loudspeakers are now delivering. They are being driven by Oppo 105 upgraded, John Sampson upgraded Musical Fidelity A1. All solid core power/interconnect/speaker cables.
This project was only completed 'confidently' with the kind, generous help and insights from Willys HIFI who supplied all the excellent Mundorf components.
Cannot thank Will enough for his patience and knowledge. My lack of knowledge and understanding was never a barrier to success only because Will was so helpful, enthusiastic and interested in my enquiries. Will cautioned against my extravagant choice of caps. The results could not be predicted and so a more responsible and cost efficient choice was Will's sagely recommendation. Trustworthy, Knowledgeable and Approachable. How refreshing. My choice was a gamble to push the limits and the budget, the results are beyond my hopes and expectations.
Highly commendable service and support. Outstanding in the Audio/HiFi marketplace.
Thank you Will.
John.
Thanks for the comprehensive review John !
Will & Caroline
Friendly technical support
40+ years in the trade
UK family run business
Excellent customer service
Quick dispatch
In addition to my post from 17/11/2025, here is some information on the final status of the project: Saving the Mission 752 loudspeakers.
Once it was certain that it would be possible to revise the loudspeakers (thanks to Willy), the desire to also replace the low-midrange drivers and convert the crossover to a high-quality version quickly arose. I was fortunate enough to be able to purchase two Burmester 949 MKII midrange drivers from Audax to replace the existing low-midrange drivers (52LFHDA – still available and can be sold). They are practically identical in design, but significantly more refined and powerful. Revising the crossover proved somewhat more difficult because the values of the coils were not printed on them. However, they can be determined by measuring the originals. Mundorf resistors, coils and capacitors of the two highest quality grades were installed. These are not exactly cheap, but once the speaker is finished, the difference is clearly audible. The crossover was also modified slightly. A shunt was integrated into the high-frequency branch. Following a tip in a forum, the crossovers were also moved to the outside. They are currently still on the speaker without a housing. The metal housing provides perfect shielding. As the Willys tweeters are very efficient, they were ‘damped’ slightly. The final cost of the conversion was approximately £600. In return, the speakers now perform at a level that far exceeds their original condition. An exciting project that was only made possible by Willys – thanks to Caroline & Will ❣️
Id had these speakers for a couple of years. I got the S/H and already the tweeters weren't working when purchased. Played them for and while but parked them up hoping one day to organise tweeters. Well that day finally came and i am blown away. Easily better than my Jamo 507A's and TDL RTL 3's. I drive them with an adcom 5300 and nad as pre amp. I am in New Zealand. The turn around time was within 2 weeks. Saving up for the crossover upgrade.
This made a massive difference to my 30 year old Linn Keilidh speakers, giving them a new lease of life.
Willy's is an awesome serivce. I needed a 4" midrange replacement that is a drop in exact fit for the IMF TLS50. If you are ordering from the USA, the Monacor MSH-115, 4" is your best option. I live in Pennsylvania and it only took 5 days from the time I ordered to be delivered from the UK. Royal Mail provides tracking. I dropped in cab and was fired up shortly on the same day. Sounds great. Totally worth buying these instead of rebuilding old speakers.
Willys saved my Mission 752 speakers. The tweeters were defective. The original tweeters are no longer available, and it would have been a shame to throw away these really good speakers. I came across Willys by chance in a chat room. Even there, the company and especially the tweeters were highly praised. I contacted Willys and received a very friendly response. Ordering the speakers went smoothly. However, shipping to and from the UK is a real adventure due to ****. It is expensive, cumbersome and no fun for either side. The tweeters arrived two weeks later and were of course installed immediately. The result is truly impressive. Airy, clear highs (previously a weakness of the 752, which tended to ‘hiss’) and a sound image that really thrills me. The ‘old’ Mission 752s seem to me as if they have been swimming in a fountain of youth. Thank you for the good service and the high-quality tweeters. ❣️❣️❣️
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