My HIFI systems 1970s to 1980s

Content:

1. Mono HIFI, early 1970s
2. 4 channel HIFI, late 1970s
3. 2 channel HIFI, early 1980s

Note:
I take no responsibility or liability for what are written here, you use the information at your own risk!

What I'm writing here are not about any fancy super HIFI equipment but something that was important for me, to built something by myself.

2: 4 channel HIFI, late 1970s

Now I had a real problem, I wanted a stereo power amplifier, a solid state tuner and two new speakers. But with not so much money, how to solve that ?

Power amplifier:

I had started working and even if it wasn't a good salary I at least had something. I had now money to built the power amplifier I found in the Radio Television magazine last year. It was at that time a power full one, 75 Watt at 8 Ohm or 150 Watt at 4 ohm. And most important, it was something that I could built myself. And when I do that, why not have 4 channels ? It must of course be much better, at least more exiting. I bought all the components I needed. The two 300 VA transformer wasn't cheap, and the eight big coolers cost a lot too. Some of the components wasn't easy to find and maybe it took me six months to built it. The electronic design wasn't very stable and the first thing that happened when I powered it up was that the power transistors got damage. I replaced them with a new model that could handle higher voltage and also solved the stability problems with a modification. After that I had no problems with the power amplifier.

Tuner:

Next thing was to replace my vacuum tube tuner with a solid state construction. My plan was to built it myself, but I found a Dynaco tuner for less price than I could built it by myself. It was the Dynaco model FM-5, it was told to be very good. It was the Swedish company ELFA who great offer and sold them for a very low price. They had other Dynaco equipment too but I had no money for that.

More information about Dynaco FM-5:

• https://www.hifispeaker.wiki/ item/ dynaco-fm-5 (Dynaco FM-5, Wiki)

Twin speakers:

And last I need two new speakers. The famous Swedish Carlsson speakers was copied by many, I bought a kit of the Carlsson OA 5 model. It was bought from a man who lived in Örby. The wooden parts was already pre cut to correct dimensions. The man who sold it worked at LM Ericsson and had connection to Sinus, a company that manufactured speaker elements. Each speaker was equipted with: one 8" bas and four 1" treble elements. For some strange reason I covered the the speaker box with a blue wallpaper, the same as I had in my bed room. At least they got an unique look.

At last I found a photo of my unique blue speakers. I'm sitting in the blue sofa with my blue speakers, blue wall paper , blue heater element and blue jeans. Could blue had been my favorite color ?

My friend Robert who also built his own HIFI equipment but with another approach, he used Sanken modules for the power amplifier. Later he bought my blue OA 5 speaker replicas, but they got stolen. So if you find some old Carlsson speaker replicas that have blue carpets on it, it's for sure my old speakers :-) .

Cabinet:

I made a very sturdy cabinet where I could place my HIFI equipment. I don't wanted any vibrations to the turn table, it got very heavy. This photo is from 1978.

Equalizer:

After that I had bought all these new equipment I felt: now I must built something by myself again. I got inspired by the trend to have an equalizer to control the sound. I built a four channel variant. It had a lot of inductances in its filter that I had to wound, very time consuming. Maybe I built this equalizer in 1976.

It wasn't only a equalizer, it included a pre amplifier too. The RIAA correction and its amplifier was put into a shielded box to reduce the hum. At the bottom of the front panel, a lot of switches to control the signal path.

JVC cassette player / recorder:

The last thing I bought in that era was a JVC portable cassette recorder and player, modelCD-1636. It had received very good comments about its qualities. I thought it might also be fun to be able to bring it outdoors and make recordings, I only did that once. I bought it in a radio shop at Gullmarsplan and it was at 1977.

More information about JVC CD-1635 mk II:

• https://www.hifispeaker.wiki/ item/ jvc-cd-1635-mkii (JVC CD-1635 mk II, Wiki)

Black paint:

A bit later in 1978 I have painted the equalizer and the cabinet black. If you look carefully you will find a headphone, Yamaha HP1, very advanced for its time.

Sonab OA 2212:

At 1978 I had used my equipment a couple of years, one problem left to solve. I had a 4 channel amplifier but only two speakers. I was already familiar with the Carlsson speaker design and now I have a bit better salary. Can I buy some new speakers ?

The Sonab 2212, the top model was very expensive, more than I could afford, I must solve that ! The reseller Söderberg at Sveavägen in Stockholm had an offer and sold them to a very low price, I think they want to empty their store from them. I bought four of them and it was the most advanced model, Sonab OA 2212. The number, 2-2-12 tell that it has: two 6.5" bas, two 6.5" mid range and twelve 1" treble elements.

More information about Sonab OA 2212:

• https://www.carlssonplanet.com/ en/ speakers/ produced/ sonab-oa-2212/ (Sonab OA 2212, Carlsson Planet

4 channel source:

At that time it wasn't easy to find 4 channel sources, only some movies and it was not a discrete source, Dolby Logic. Some musicians used it too, Pink Floyd and others. It was recorded on VHS tape which I didn't have at that time. JVC had a concept of vinyl recordings with four channels, but it was never introduced on the market.