Wednesday, 23 March 2022

Belles DMM Preamplifier

One of the more interesting preamplifiers I've had in my main system. I had it for years and kept it around, even hauling it to another province. I've only had a handful of active preamplifiers and I've always liked the Belles DMM that I had. I only stopped using it when in my current step up there was not enough steps in the volume potentiometer. It goes from soft to too loud in a single step. Had to use the "mute" function which was a 20dB attenuation to make it work.

It was a nice basic preamplifier with all the basic features one needed. It has a phono input, tone controls, bypass switch, 2x tape input and 2x auxiliary input (thought one is "tuner"). It also came with a moving coil phono input in their DMC model.

This one is unique because it is labeled as a DMC but, does not have the internal switch for a moving coil. It is a DMM that has a DMC faceplate. Why? Absolutely no idea.

But, it was a very nice sounding unit. Class A, if that means something to you. Also doesn't have a power switch, you just plug it in and keep it on to keep it stabilized before use. 

This one also had the main outputs jacks replaced with better ones.

It was a very nice sounding preamplifier, it was pretty clear and dynamic without adding too much color to the amplifier I was using. I've compared the DMM with my passive preamp. The DMM does add a little bit to the overall dynamics, especially in the bass over the passive but, I couldn't hear additional "warm" or color over the passive. That's pretty good in my books

Outside the volume pot, I had no qualms about it. I also liked the compact format. Vinylengine has a downloadable brochure on the DMM and DMC, well worth the read if you can access it.

Specification via VinylEngine:

Frequency response: 20Hz to 20kHz
Total harmonic distortion: 0.002%
Input sensitivity: 1.25mV (MM)
Signal to noise ratio: 85dB (MM)
Output: 9V (Pre out Max)
Dimensions: 19 x 2.25 x 7.5 inches
Weight: 7lbs

Old pictures:


Sunday, 6 March 2022

Technics SL-1600mkii Turntable

Ever since I've started into the audio hobby, I've always wanted a Technics SL-1600mkii. I've had two of them before and every single time I sell one, I always want to get another one. Why? They are such nice tables.

I know there are better tables out there, such as those with electronic damping arms (JVC, Denon, Sony) or even pure manual transcription base tables (like the SP-10/15/20/25 and their lovely EPA-250 arms and such). But, I've always liked Technics as a brand. They've always made solid turntable, especially their direct drives. 

The SL-1600mkii seems to be an amalgamation of different school of thought. While weighty at 10kgs, it employs a suspended platter and arm (albeit, unlike a Thorens), fully automatic with a well damped platter. There are other suspended direct drive turntables (Pioneer) but, the overall reliability of them isn't as high as the Technics. 

Built quality is always good on them, though they have a weakness with the nylon-type gears. But, for the most part I haven't had any problems with mine (I did apply sum new grease on them) and the table itself is over 40 years old. Of all the electronically controlled fully automatic tables I've had, the Technics has been the most reliable, which is why I tend to like them.

After replacing the belt, this one has been performing flawlessly, even being taken apart on various occasion to perform basic servicing. Disassembly isn't the easiest but, wasn't difficult at all.

The overall aesthetics I find quite pleasing. I like the red strobe light, the pop-up stylus light and how quickly the platter starts and stop. It is a wonderful table to use. Unless, you have clear records (LPs).

It uses photosensors to detect the size of the record being played. So, if the light passes through your clear vinyl it won't play. Luckily, I have the original paper disc that you can rotate to cover up the sensors on the platter. I usually keep it with my sole clear record.

There's a lot of things to like about the SL-1600mkii, VTA adjustment, adjustable pitch control, and able to get some KABUSA improvements. Not to mention Technics, as a whole, has quite the interesting history.

Specifications via VinylEngine:

Type: full auto turntable
Drive method: direct drive
Control method: quartz synthesizer
Motor: DC motor
Platter: 332mm 2kg aluminum alloy die-cast
Speeds: 33 and 45rpm
Pitch control: 12%
Wow and flutter: 0.025% WRMS
Rumble: -78dB
Tonearm: universal static balance type
Effective length: 230mm
Overhang: 15mm
Effective mass: 12g
Dimensions: 149 x 453 x 399mm
Weight: 10kg

Saturday, 11 December 2021

PSB Avante

If people have forgotten, Canadians make great speakers. Here are one of the original designs that came out during the early to mid 1970s that started to use the NRC anechoic chamber. PSB like many others Canadian brands (the most famous would be Energy with either Energy 22 line) had access to this wonderful camber to create/design their speakers.

These PSB Avante speakers are one of the originals that came out of the NRC during that time. From what I've been told, there is actually a pair in the museum. There are quite a bit of information about the NRC and the man behind the scene DR. Floyd Toole who help many Canadian brands make their mark on the audio scene. Potentially, it is possible Paul himself may have help built these speakers as Paul's father was a cabinet maker, and these cabs are well made with nice bevel fronts and very nice real wood veneer (walnut?). 

What makes these speakers unique are the black silicone blobs on the woofer. Why? I guess paper cones had different consistencies back then and the added weight help create the "sound" that PSB wanted by adding mass. Newer PSB Avante had the same model woofer but, probably better consistency on the paper material.

The drivers aren't anything unique, they are all Philips drivers, it's the "tuning" on the woofers that make them interesting. I am pretty sure these speakers came out of a book/magazine by Philips on making speakers. Though these crossovers designs are different than the ones I could find from those PDF files I've read. Initially, they sounded alright, pretty flat with the peaky tweeter but, overall pleasant.

The crossover is quite simple, a couple resistors and air coil inductors with a single electrolytic 10uf capacitor, which was replaced with a brand new matched metallized polypropylene film capacitors.

Quite a bit of effort was done in recapping these speakers. The grills were quite difficult as the main adhesive was probably a RTV silicone and it was used in everything so I could only do the bare necessities with my basic tools. I did redo the grills with black speaker grills as the old ones were quite worn out and they do look nice. 

So how do they sound? Initially, they were still a tad bright but, I guess with the burn-in time, they mellowed out. They sound a lot clearer than previously and when driven by my lovely recapped Pioneer SX-636, it quite the vintage eye candy. Surprisingly, it does have good amount of bass. the 8" long throw woofer isn't something to snuff at. They are pretty decent. Philips made good speaker drivers. Even the tweeter is pretty nice. They have good spatial breath, good separation and gives an illusion of a wide soundstage. Very pleasing to the ears. 

Finally, I gave the cabinets a rub down of oil and they look lovely. While they were in decent shape to begin with, the oil helped give them a pop back to life.

Overall, I think many would be quite pleased with these speakers. I personally think an 8" woofer is quite adequate for most living spaces as it offers enough bass to provide a "full" sound. These are fairly neutral speakers and will probably work well with most type of amplification. I've driven them with my 200wpc power amp with no issues. They work well with music and movies. Big plus to Canadian speakers!

There are some specifications online but, they are of generation newer over these ones. But, I suspect they would be very similar as they too used Philips drivers.

Saturday, 2 October 2021

What a crazy year!

 It's been a crazy year!

Things have certainly changed over the past year. Sadly, I am no longer in Winnipeg as I had to move to British Columbia. Though, I am not overly active, I still hope I can write up on some gear that I hauled to BC with me or stuff I find. Though, my new living arrangements has shrunk since moving.

Currently, I am in the process of refurbing a pair of original PSB Avante. These are the first generations that had silicone goop aka caulking as both an adhesive/gasket and to add mass to the woofers. They are also done up in wood veneer unlike the later generations. My refurb consist of new grill cloth, new poly cap in the crossover and new speaker binding post.

I will also be refurbing a pair of another speakers after the PSB. Though, it will be a slow process as I have other things that I must do. 

Sunday, 29 March 2020

Technics SL-D2 Turntable

From a vintage turntable point of view, I personally think Technics (primarily their direct drive models) are some of the best built vintage turntables available. They have excellent motors (even their slim line p-mount turntables are very good), well made, and extremely easy to service.

For the most parts, they do not require much, some oil as per the service manual and simple cleaning and adjustments of the controls.

Some negatives of these series of turntables are the hinges, well not really the hinges, they are robust. It is the plastic tabs on the dustcover that insert to the hinges. Those tend to break. There are remedies all over Audiokarma if you're looking for some.

Another sore stop is the mat. The Technics mats are generally great mats but, for some off reason I've noticed they become hard (frisbee hard) and start to leech out oil which makes cleaning an awful mess.

Thankfully, this Technics SL-D2 was in great condition. But, needed a few items. The mat had started to become hard so it was replaced with a very nice JVC QL-Y3F mat and a headshell with cartridge. The dustcover was in excellent shape and the plastic tabs were perfect as they can be for a 30+ year old table. It just needed a good cleaning to remove the built up grime.

Some basic specifications:
Platter: 312mm aluminium alloy
Speeds: 33 and 45rpm
Motor: B-FG servo controlled
Pitch control: 10%
Wow and flutter: 0.03% WRMS
Rumble: -75dB
Tonearm: static balance, tubular
Tracking force adjustment: 0 to 2.5g
Effective length: 230mm
Dimensions: 430 x 130 x 375mm
Weight: 6.9kg

The Technics SL-D2 is a 2-speed, direct drive, semi-automatic turntable. It has a pitch control, a cut/stop button and the ability to "stop" the platter by having the 33/45 switch in an neutral position. This was a very common turntable, retailing around $200USD back in the day.

I like these tables a lot. Considering the current market in Winnipeg, they are very hard to beat.

I would put this above the Akai AP-D2 and multiple others because of the overall quality and ease of servicing and maintenance of these turntables.

This Technics SL-D2 is equipped with a Spectrum branded Acutex 310IIE cartridge with a brand new aftermarket elliptical stylus. These Acutex cartridges are always nice sounding, not as dynamic as an Audio Technica but still very capable. Dynamic, a tad neutral, with good detail all around.


Thursday, 19 March 2020

Mirage Omni Series

One of the last series of speakers that were made by Mirage that were available in Canada (or at least in Winnipeg). I originally bought these for my parents however, they never used them and even left them here in Winnipeg when they moved out of province!

I've only listened to these speakers maybe a handful of times and once at Visions Electronics. When they were being demonstrated for a sale I was very impressed on how beautiful they sounded. I was running them with a Crown D-75 power amplifier and Belles preamplifier.

They were very immersive sounding, I guess the "omni" part were correct, while they were not as direct sounding or a sharp sounding as other speakers they were excellent for what they were designed for. This was one of the reason why I bought them in the first place, for my parents to use them in a home theater setup.

Truth be told, I do have a soft spot for API speakers, even though this was made during the Gentec era. I love Canadian speakers, period.

The overall presentation when sitting about 10 feet away was great. Airy, neutral and definitely the 550s (6.5" woofers) were bass heavier than the 350s (5" woofers). Vocals were nice and clear and the overall ambiance was nice. What's not to love.

Cabinets were beautifully designed, curved not squared or rectangular. Aluminum tweeters, which at times I prefer, and rubber surrounds. They are truly well made speakers. Grills were a bit of a pain to remove and be careful of the plastic speaker grill pegs.

These are gone but, they still left a lasting impression on me. I may update this with more information later one as this is definitely for posterity.

Akai AP-D2 Turntable

Akai AP-D2 is a direct drive turntable of the very late 1970s and early 1980s, usually the straight tone arm is general sign to "age" a turntable. I've had many Akai before and definitely had my fair share of AP-D2s and they are solid tables. Easy to use and more importantly quite easy to service.

It is a 2-speed direct drive turntable with automatic return with a "servo lock" which locks in the speed, therefore this guy does not have adjustable speeds pots.

Overall, it is a solid direct drive turntable. This one was equipped with an Audio Technica AT-3400 (probably originally a rebadged version of the Audio Technica) and a new aftermarket Jico stylus was installed. Sounds great!

This is really a no-frills direct drive turntable with basic features but, that's all you need to make music!

This guy was in excellent condition. And, now found a new home!