YHZ Sound Co-Op Repair Shop
79 Jackson Road B3A 4V7 Halifax, NS, Canada

GOLDEN This F# (70) was dead - tried almost everything - no charm, no sustain. To put a bright new tine in mid the high end of 45 year old pieces was gonna stick out like my soar thumbs I now have from chemicals and buffing 73 tines. I found this ring with no owner 35 years ago - its 10K of gold is now better served dont ya think. The Rhodes has 1 gold tooth and the #70 sounds sweet with a spring clip for sustain that hadn’t helped (at all) previously

Wally Robert- I’d call him an icon of broadcast TV history, and greater still my great friend Warren Robert’s dad, bless his angelic soul. Broadcast equipment was kept to stringent calibration, in some cases tubes were replaced on a preventative maintenance schedule, new tubes tested prior to install. Wally amassed this collection and more lol - there are as well quite a few NOS valves in that box. The man had foresight! Hoping these to come in handy. Need and odd ball you can’t find? Certainly I don’t recognize half of these. I’ll be cataloguing these shortly

Rhodes Action: This 73 is a bit Borged already, but still with its wooden keys. The action impossible on 3 bass notes, we break it down to get at the straps. Often the set of 12 notes is replaced - ha. The moulded parts, old they’re brittle and apt to break when bent as they would have originally. Not prying the jaws open, the strap can be shortened or lengthened slightly by sliding strap sideways out of the jaws, reverse to reinstall. Much assembly to test, most times a few mm is sufficient to play soft notes again

dbx 166 dual dynamics processor. dbx (founded 1971) comes from decibel expansion - basically a property of a circuit central to their early products like noise reduction. When mixing bass I’d use this post any main processing (Eq or comp) and send things like kick drum into the sidechain giving the reigns of the bass to the drums so to speak. These dbx products are pretty transparent and so do what they do kindly. The 160X still famous and modeled into a plug-in. I use four... channels of 929 on Foley and SFX when recording and for dialogue fixing - a smooth process to this day after almost 50 years. When servicing this, was careful to pair capacitor pairs - it’s easy and reasonably quick and important here for DC offset. Original switches were toast - exact same kind in every large Soundcraft console ever made - not a bad switch - short life. The replacements not much better but there’s a price leap from $5 to >$25/ and from there on up. Recycle, repurpose, repair - reap rewards See more

1950(s) DuKane 50 Watt transformer-coupled mono-block amplifier! Pretty cool and in top shape inside. A gift to me - thanks Warren Robert. The PNP 2N2147 (Germanium) tests bad and I’m not sure if it’s original and seems impossible to find any info on this amp - so as I happen to have one PNP3055 I’ll try hauling a car load with a big truck. The two NPN are 2N3055 and test fine. Without paperwork- can’t be certain the 2147 is original and as it’s blown makes one think was a bad replacement / possibly. Would be great to find an original Dukane preamp as I see such things out there in cyber land but maybe it needs a custom build that looks like it This diode pair is press fit into place (full wave rectifier) - sexy as all heck!!! Love the hinged box

KUSTOM CHARGER! Bass amp Made in Kansas. Had many issues so I’m glad I had some salvage Kustom boards to scab original parts. Basically rebuilt this less the smaller resistors that checked out and only 2/3 of the devices! Troubleshooting the noise further I find much in the 14 pin chip after solving most issues. Back to the salvage boards I pull 8 chips to compare on a quick test circuit - lo and behold each chip has its own gain and distortion - so picked two and installed a socket to test them in vitro. Of course picked the louder and lower noise. With little to do with this amps tone I’ll look for a quieter modern chip. These chips are internally compensated to remove the need for external resistors - a trend at the time now standard. Love tube amps, but I’m more a bass player and appreciate a good transitor amp

CAGE IT / This 1950s Harmony back in for an EQ tweak and some good shielding for 2020. Love the perf steel for vintage look

Vintage metal film in oil capacitors in 2020. 70 years later these caps are functioning and within 30 to 50% of labeled capacitance, but as we can see these are leaking oil- what the composition is I’d only guess what was available, perhaps something nasty like PCBs used to pot transformers. Look closely and we can see the leads are copper - common to today’s audiophile capacitor. If you have an old amp, might be a god idea to vet any leaking oil or electrolytic caps. As capa...citor electrolyte chemistry is a highly guarded secret - who knows what’s in the old ones. We can buy ROHS compliant parts today without lead or banned chemicals. When it comes to making old things sound like they should in 2020 it’s common for me to resort to parts made in the old ways - quality metals, polyester and polypropylene for caps and wire or carbon resistors - makes a difference in noise and tone. I guess here for the music/tone I bypass some of my own rules. Last year I began comparing ROHS products to the equivalent old school parts, but unless I fill an amp with the parts it’s hard to get a sense of what will happen overall. Life - one experiment after another See more

D112 common simple to fix issue. I prefer a few drops of wax here over glues

Golden Audio - This studer module sports some killer switches we don’t see anymore with few exceptions in the audiophile equipment world. Where a few pennies in gold and epoxy make this switch near immortal it as well passes audio exceptionally- the bright shiny surface an excellent conductor of HF. As well as can see the contact material is thick - great for LF. So when you’re wondering why an SSL console or Avalon preamp pass signal so well, it is in part these details that make for a great audio device that we can count on to last. Check out the thick insulated can over these Phillips electrolytic caps here

TAPE OP. they called me - some days anyway. I miss that daily analogue relationship with tapes and finely tuned mechanics and electronics, large remote controls... This Roland 201 I suggest had a fair bit of alignment issues out of the gate. The tape guide here has an opening more than 0.005 larger than the 0.250 tape so it’s riding up and down the heads - drifting in and out of alignment. As well the head wear shows this. Swapping the left guide for the right, a better fit, shows we need a new guide - simply wasn’t made very accurate in the first place and brand spanking new likey wasn’t much of an issue. This 201 lived in Japan until recently

Golden! No oxides, no collected debris - this National Semi voltage regulator - the coolest I’ve seen, seems to work like a dream. Silver a better conductor than gold but the gold doesn’t break down. Texas Instruments makes a 340T but nothing like this - in a quick search I couldn’t find anything like this - those days are gone

I’ve always wondered of current when it dips into the negative. If the current loss is the same why do we see this happen. Typical of positive and negative voltage regulators, I’ve rarely replaced a negative reg, but always clean iron filings and such off the positive charged devices which are attracting negativity charged dust. Is there no positive dust

Show me your tongue Visted with the great Brit Fader last week. He is well and deep in repairs. I could listen to Brit’s stories all day and he doesn’t mind talking capacitors lol. Some devices can function better than when they were new with some good attention to quality where it’s most required. Ploughing through some repairs myself until Aug 1. Reopen shop near end of October, but through Sept Oct can take on some emergencies in the evenings. Quickest to PM Christopher Mitchell rather than this repair page as it goes - not so keen on how fb organizes messenger messages so I’ve not taken their offer to organize them ha

PLEASE CONTACT ME (CHRISTOPHER MITCHELL) DIRECTLY VIA MESSENGER. FB not working for me. NOTE: Repair Shop open until end of July. Re-open some time in October

In August 1937 The Toho Industrial Research Laboratory commenced research and trial manufacture of selenium rectifiers . The laboratory was dissolved at the end of the World War 2 and the late Tetsuji Kotani, who was the chief of the semiconductor laboratory at the time, inherited the engineers and facilities, and established Toho Sanken Electric Co., Ltd. In 1962 the name was changed to Sanken Electric Co., Ltd.. Sanken North America, Inc. (controlling company in North America region) was established in 2013. Now a diverse company, they still make quality transistors though very small This Yamaha would make a good two channel bass amp - with new caps - sound like new. Is advised the owner they might find something better to revive but they wanted this puppy and it will live for many years

SAFE & SOUND - I’ve made great use of this mitre saw investment - building studios, sets, renos, albeit now I’ve given her new purpose. Workpieces wander when not well held in place and it’s a bummer to cut a piece only to not have it perfectly fit/cut as was set in the saw. The commercial hold-downs are wimpy and don’t clamp the pieces next to the blade where the force is needed so I started there -replacing the cast aluminum arms with 1.5 square stock steel and added set s...crews and steel plate for the holders. The jig is fashioned around two (g)un (b)arrel vise blocks (a maintenance tool from China). This jig or holder made for gently handling non-Ferris rod, mostly solid copper rod. Even my supplier in the business of cutting metal had problems with the round stock and the sticky copper so a solution was required. This the first cut, I wasn’t sure if I’d slide or chop with the saw - this was a chop down and I be happy The supports at each end help to square the piece with the blade. With the overall holder/jig built I imagine making a set of blocks to hold other things and sizes. The hold downs worked out great for any wood working as well. A friend had said, why not start making your own tools - good idea, thanks See more

Balancing Acts - unconventional producers often need unconventional mods. With not much room on the side and a monster dial sticking out the front I thought - cool, they can change the tone easily this way. With the transformer output strapped directly to the gain pot, one can simply turn down to pull the T. This is a vintage replacement for a Western Electric Transformer. Not sure if it’s value but it’s identical in specs to the WE valued about $400 at auction. Capacitors couple very well, still a transformer I’d argue and after decades carries more depth and detail to a signal And she got a new lid while she was at it (perf. steel top)

Something special about things in a box. I was super impressed with these pickups today telling us an old story - Faraday was right. Improve on the dogma with thick gauge steel like military comm, and you can dip further into the silence - a conversation I’ve had with the real deal by the by. Hands down the quietest set of single coils I’ve heard. The screws are into a plate below so I’m imagining the poles are grounded. Curious is the face shape of the pickup. All the braided circuit wire was oxidized but it sounds choice Forgot to mention the strange colouring of the metal - perhaps a bit of tempering colours, not sure