Another day, another sickly Cyrus One arrives for the workbench. This one looks as if it's previously been attended to by Messrs Bodgit & Scarper having failed to master any real directional control of a soldering iron thus melting the electrolytics sleeve but then failing to solder it in at all!
As expected the first of many, not often I see these two as bad as this.
First patient of the day a Cyrus Two whose owner complains of noisy input selector. They didn't even comment on the poor bass response on the right channel (green - left/purple - right) just measured before I start on it! Plenty of duff electrolytics in this one I predict!
Planning on purchasing an Arcam internal phono card for your Delta 290 or Alpha 9 ? Do ensure that the plug on your amplifier PCB where the card fits onto matches the socket colour on the phono card you buy. Otherwise it won't fit properly as there are 2 types. Most common is the white one.
Wednesday’s @thetimes.com cartoon times.newsprints.co.uk/peter-brooke...
A&R Cambridge A60 on the workbench fully loaded with all options:
MC Cartridge loading module and preamp (price £8.50 and £24.95 in 1982!) The upside down PCB is a pre-out buffer amp on what was the Aux input DIN as this amp is an A60AP with split Preamp/PA instead.
A nice NAD 3020 just fully overhauled complete with new RCA's and speaker terminal upgrade and now on it's way back to it's owner.
A great example of 40+ year old capacitors leaking the chemical used to form the electrolyte between the coiled up internal plates. Quite common now with earlier versions of the A&R Cambridge A60.
First example of this rare Cyrus amp seen here. Looks like a Cyrus 2 but no input RCA's and plenty of 4mm sockets at rear. It's basically a bass only amp for the Mission 767 speakers with minor adjustment available. Known as an LFAU or Low Frequency Alignment Unit. Same faults as a Cyrus 2 though!
One vote cast!
In 40 years I don't think the number of failed ceramic caps I've seen has made it to double figures yet! From an NAD3020 PA stage & should be 100nF not a few ohms & caused a 4v dc offset on the output (should be zero). Time consuming to trace but luckily for the customer it's a fixed price repair!
It's very common with those particular two, Roederstein was the brand and at the time a quality offering but after 40 years or so they've done their job!
Cyrus Two with left channel reported quiet. 1st graph shows left channel lower trace and right upper with former having a severe roll off all the way from 50Khz down to a few Hz. Cause is those 2 dying brown electrolytics that form part of the PA feedback path. 2nd graph is what it should look like.
An interesting 1982 price list for A&R Cambridge products found in an handbook passed on by an ex-A60 owner. If the A60 were still on sale at todays prices then it would be almost £750 including VAT.
A reminder in the sky yesterday from a site once used by ARS before switching to BlueSky perhaps?
Almost 220 NAD3020's have passed through the workshop to date but they are dwarfed by the Cyrus One and Two's which are nearing 800 now. There is one major manufacturer that does redirect enquiries for a couple models in my direction which I really appreciate though.
That was a mess. Saw an equally rough bodge at one of the kids places recently, an instant 9.5Kw under sink heater fed as a spur from the back of a kitchen 13A double socket! I was struggling to find where to isolate it on the board initially before the discovery.
Test of a Cyrus 2 before overhaul clearly shows slight left to right channel imbalance and also a small phase difference between channels in 1st image. Almost always down to electrolytic failure as indeed was the case with 2 completely dead electrolytics in the PA stage. 2nd image after replacement.
Really nice to see this recent UK start up producing amps/sources with British components/materials and really hope they succeed especially having designed these with repair and long term support in mind. www.whathifi.com/news/fell-au...
Enjoyed having a quick catch up and a good idea to plan another in the future (just west of Cambridge is midway). Hope you and the family enjoy the rest of the break!
Have a safe trip, Aldeburgh (incl Thorpeness), Framlingham & Southwold really lovely towns near to where you are, give Leiston a wide berth & Saxmundham not worth bothering with either apart from a good Tesco/Waitrose for supplies.
Currently testing sugar cubes...
Common damage on an Arcam Alpha 9 not correctly packed to survive transit. A knock during shipping to the balance/tone controls just snaps potentiometers clean off the PCB. Even a risk during overhaul unless you remove the metal rear fascia to avoid accidentally stressing it while on the workbench.
Planning on purchasing a used Cyrus One or Two amplifier (or 'preloved' to use the current fashionable term!). See this concise handy buyers guide here before potentially handing over your money for a flaky Ebay example and ending up disappointed!
www.amprepairservices.com/cyrus-buying...
A real shame to see a whole sector of engineering that we were trained for just fading away but HF in particular should just be abandoned now and broadcasters should stop wasting energy & expenditure keeping it going. It's about as productive as trying to heat an ocean with a fish tank heater!
Two early Musical Fidelity A1's this week both with the same fault causing channel loss. This input selector switch has several broken solder joints on the pins that solder to the PCB. Caused by slight movement each time the switch is operated eventually fracturing solder joint (no mechanical mount)
It's rare to find a Musical Fidelity A1 where the PCB holes line up with the base threaded inserts. This one just had the 2 M3 studs at the rear and the 3 M3 screws for the front were just left out at the factory! Not bad amps though, produce a typical 12W Class 'A' before entering AB then ~26W max.
Perhaps as the valves have run out they can't even get them rebuilt reliably any more. I used to get many of the valves from the B6122's in Antigua rebuilt at a place in the US. Most worked well as long as they were carefully conditioned on arrival and then powered up gently in the Transmitter.
Many plugs are such a tight fit that plugging in/out over many years eventually tears the socket away from the PCB which is only attached by the 3 solder joints. These replacements overcome this issue and mate far better to modern RCA plugs used. Additionally red inserts are used to identify the right channel inputs and white for left channel as this can be confusing as designed by NAD.
Replacement RCA sockets now available for the NAD3020 as an option when your amp is at www.amprepairservices.com for overhaul. These mate far better to modern RCA plugs. Also red inserts are used to identify the right channel inputs and white for left as this can be confusing as designed by NAD.
Clearly recall riding up that hill for the first time after a snowy 140 mile freezing ride on my Z650 in early Jan 86. Last saw it in Jan 1990 when I left for Masirah as they shut the transmissions down whilst I was away. Cold war finished, Russia not bad guys any more so no need they said......
