Decca Stereo Decola information

[Jamiesjamies]

Hi there. This is my first post on the forum. I have been lurking for awhile and have learned a lot from various threads. I don’t currently have any vintage HiFi but have become slightly obsessed with Decca equipment, and am on the lookout for a near mint Deccalian 88. I am posting, though, because for me the pinnacle is the Decca Stereo Decola. I have seen period adverts for it and as well as the common design that we all know, it says “contemporary style will be available.” I just wondered if anybody knows if any were made in a different style, or if there are any special order finishes in existence, for example an old Bonhams listing had the mono Decola and TV in special order bleached birds eye maple, it was gorgeous! So any thoughts, information or knowledge on this amazing piece of HiFi history would be most welcome!

[RojDW48]

This is one I had for a few years and restored with the help of another member. They are truly spectacular instruments. I listened to it for a couple of years after restoration but sold it coz it took up so much space!! It went, inevitably, to Japan, where they are regarded with almost religious reverence. Not an easy thing to restore - the electronics are peculiarly 'Decca' but well worth the effort. I bought a Decca Stereo Decola demo record, which referred to transistors, but I have never come across a transistorised version.

[Jamiesjamies]

Thanks for the pics! There was one on eBay last year for £5k which I thought was a lot but when I saw what one was advertised for in Japan I understood why! Would you say the quality of sound is as good as modern hi fi separates?

[Edward Huggins]

The sound will not be like that to be experienced on "modern hi-fi", nor should you expect it to be.

It all depends on how much you enjoy/have enjoyed sound from vintage valved equipment. I guess I need to ask you first what valve systems, old or new, have you listened to of late?

Given this, we might better guide you as to what to expect.

[electrogram]

I have never owned or heard a 'whole' Decola but I did once own pair of the 'separates' speakers. These look like the ends of the stereo Decola and have the same drive units. It maybe heresy to say so but I thought they were pretty poor, sounding boxy and nasal and generally leaving a lot to be desired. The cabinets were surprisingly light in weight too.

[rontech]

I heard one of these at Radiolympia. I cannot remember if it was 1959 or 1960.
I do recall it sounded pretty good in the context of the day. I think that pickup arm / cartridge was considered one of the best available at that time.

[barretter]

The stereo Decola cost 395 guineas in 1961 which is about £9000 in today's money. It contained a couple of 15 watt amplifiers comprising an EF86 input valve, an ECC83 phase splitter and 2 EL34s in push-pull. I think the one the Japanese lust after is the 1949 mono which contains PX25 triodes.

[snowman_al]

Originally Posted by Jamiesjamies

Would you say the quality of sound is as good as modern hi fi separates?

Not even close. It was 'right' for its time, but not hifi even then...

[Cobaltblue]

Originally Posted by barretter

The stereo Decola cost 395 guineas in 1961 which is about £9000 in today's money. It contained a couple of 15 watt amplifiers comprising an EF86 input valve, an ECC83 phase splitter and 2 EL34s in push-pull. I think the one the Japanese lust after is the 1949 mono which contains PX25 triodes.

I have sold 2 of these to Tudor Reese in around 1990 they both went to Japan and I sold them for over almost £2,000 each ISTR even then.

I didn't own them both at the same time but within months of each other.

I bought the first one which I used for about a year but SWMBO was constantly bending my ear about it being in the way so I sold it to TR. Once it was gone she said she missed it so I found another one. Within weeks she was complaining again so that one also went as well.

I enjoyed they I thought of them as a pretty decent sounding Radiogram.

The filaments of the pre-amp valves are fed from the Cathodes of the EL34's so when the EL34's emission drops the filaments get under run.

Cheers

Mike T

[RojDW48]

The most exceptional feature of the Stereo Decola's sound was the stereo image. You could sit way off axis and hear coherent staging. I have heard all sorts of attempts to get that right, but none as successful. It is worth remembering that this was designed in the days the whole family sat down to enjoy a programme of music - not just one saddo pinned to the 'sweet spot' !

[barretter]

Originally Posted by Cobaltblue

The filaments of the pre-amp valves are fed from the Cathodes of the EL34's so when the EL34's emission drops the filaments get under run.

Cheers

Mike T

It appears the Gramophone reviewer was wrong and the Deccola stereo used 8D8 input pentodes for a very specific reason as explained in the attachment by somebody who repaired one. It would be interesting to see a circuit digram.

[Techman]

Originally Posted by barretter

I think the one the Japanese lust after is the 1949 mono which contains PX25 triodes.

I think that we can all be assured that any of these with power triodes that are sold abroad will end up being gutted and the remains thrown on the next bonfire or in the nearest skip. Selling one of these to an unknown foreign buyer is basically signing its death warrant!

[OldTechFan96]

Is there still a large demand for these old output triodes? I'm sure that I saw an advert for newly made PX25's.

[barretter]

Yes, new PX25s and PX4s are made by KR Audio in Prague at very hefty prices. The Art Audio company makes a single-ended stereo PX25 amplifier using them.

[Cobaltblue]

Originally Posted by barretter

It appears the Gramophone reviewer was wrong and the Deccola stereo used 8D8 input pentodes for a very specific reason as explained in the attachment by somebody who repaired one. It would be interesting to see a circuit digram.

Yes I am sure they are 8D8's as I suggested in this post

https://www.vintage-radio.net/forum/...43&postcount=6

Cheers

Mike T

[frankmcvey]

There's quite an interesting video on Youtube showing the manufacture of KR Audio valves. There's quite a lot of skilled hand work involved, hence the price, I suppose.

[Herald1360]

Whoever wrote that attachment got things wrong too- the ht transformer doesn't have to supply 150mA more current for the front end heaters but it does have to supply 37.5V more HT voltage at the total HT current to accommodate the heater voltage requirement. The extra power the TX has to deliver will be 37.5 * total ht current of which 37.5*0.15 = 5.6W goes to the valve heaters and a further (37.5*37.5)/280 = 5W to the 280R ballast resistor mentioned.

[Hartley118]

I recall hearing the stereo Decola in its launch demo at the Russell Hotel Audio Fair in, I guess, 1961.

By the standards of the day, it sounded pretty good. However, hindsight tells us that, whilst the deck, pickup and amplifier are still regarded as top notch, that speaker arrangement is, to say the least, somewhat quaint. That big elliptical woofer looks pretty cramped in its small reflex box and, as for those multiple tweeters, today’s philosophy would suggest that a one inch dome tweeter would give a less directional response than all those paper cone units. Just think of the interference patterns between the units

However, just like the original Decola gave a better sound than those three 12-inch Goodmans speakers would have suggested, maybe the stereo Decola was another example of subjective sound quality beating any lab measurements.

Martin

[barretter]

Originally Posted by Cobaltblue

Yes I am sure they are 8D8's as I suggested in this post

https://www.vintage-radio.net/forum/...43&postcount=6

Cheers

Mike T

You are right and the Gramophone reviewer is right. Here is a list of the valves used in the Decola. The 8D8s and ECC83s that get DC heating are in the control unit and the EF86s are used in the power amplifiers where they presumably share the 6.3V used by the ECC83s and EL34s, which will be AC. I should read more slowly.

[RojDW48]

Originally Posted by Hartley118

That big elliptical woofer looks pretty cramped in its small reflex box and, as for those multiple tweeters, today’s philosophy would suggest that a one inch dome tweeter would give a less directional response than all those paper cone units.
Martin

Not tweeters - all mid range drivers and, as I noted earlier, the breadth of the stereo image was extraordinary. There was a facility to add tweeters - switched jack sockets in the x-overs, which diverted the HF to the plugged in tweeters. I tried it, of course, but the result was deeply disappointing - that wide soundstage disappeared as the tweeters took over responsibility for directionality. The bass reflex cabs were suspended on foam blocks (I replaced with springs - likewise the rather lovely Collaro transcription unit) and all the internal framing was hardwood. I think we may safely assume Decca encountered a problem or two with really quite deep bass cabs in the same box as the TT !!