Phillips 830A speaker type variation

[chipp1968]

I have just Purchased a lovely Phillips at the W B auction in working order ,and all I need to do is revive the cabinet. I have an interesting question regarding speakers. I always understood that this set had a moving reed speaker and any pics I've seen on line recently show that sort, with its drive unit in the cone etc. My set has a moving coil unit which appears totally original and is mounted on a round baffle, fixed with clips that come up though holes in it, all looking pro and original. So Does anyone else have this arrangement? is it normal, maybe a later updated run of the set?

[Mike Phelan]

Interesting - as it looks like a PM speaker, I would not have thought that such a thing would be available at that time? May be wrong there.

If it was originally a mains-energised one, the coil would have doubled as a smoothing choke, so some changes would have to be made.

[PJL]

It looks like a Phillips PM speaker similar to the one in an 834A I have here but the output transformers different and the holes are covered. Perhaps it was an upgrade performed early on in it's life?...Peter

[chipp1968]

Its interesting ,I would like to find out . They definately had PM speakers in the early 30s as I had one in an HMV radiogram of 1932.If it is an upgrade its all very pro ,not a home alteration its all too cleancut and machine like

[Paul_RK]

Yes, a 1929 Columbia radiogram here has a moving-coil 'speaker: they had been around a while, but were more expensive to make than moving-iron types and so were restricted for a while to higher performance equipment. Philips' own 730A, from the generation before this set, uses one - at least mine does. This example does look decidedly like an early Philips unit and I'd go along with its being most likely a change introduced during the production run of the model.

Paul

[kolstar]

Hi

I'm certain that your speaker is perfectly correct for the british version of this set. It's a typical 8 inch Philips permanent magnet moving coil speaker of about 1932. The same unit was used in the Philips model 630 as well.

I think there exists a continental version of the 830 (might have a different model number) that does indeed have a moving iron cone loudspeaker (same as used in model 930) but I don't think that version was ever sold in this country.

Regards
Alan McGregor

[chipp1968]

Thanks that is interesting , most that pop up online are continental so that makes sence ,and some have been imported recently

[geofy]

The speaker for the 830A looks almost modern apart from what appears to be an output transformer as an integral part of the frame. Curious that my Philips 650A made in 1938 as what appears to be an older speaker design with external bolts and cloth dustbag because of the open spider voice coil suspension and cotton wicks in-between the magnet and frame.

Geof

[chipp1968]

Interestingly the clamps holding yours into cabinet are the same type as mine

I have to note that sound quality with this set is not brilliant, its OK on speech, but music is distorted. I've noticed this with a lot of my sets here which is why I don't use them. I don't know whether its to do with modern broadcasting techniques and or my aerial arrangements, plus bad reception here?

[geofy]

Philips seemed to like this clamp arrangement, I even had a smaller sixties Philips speaker that used the same fixing method. The speaker in my set sounds just as good as a modern one.

When you say you do not get good music reproduction does this apply to all sets, even modern transistor ones, if this is the case you might be getting weak and distorted radio reception, or just the valve sets you have. The speaker in your Philips should be capable of very good sound reproduction.

[chipp1968]

No. tranny sets are OK. I had a mid 30s KB with frame aerial, and that was OK as is a DAC90 which has an internal aerial. This set is presumably professionally restored, as have some of my other sets been, so It shouldn't be the set, but it's possible.

Just cobbled up a portable CD player to the pickup, both volume controls work, at least the one on the set seems to too. I thought in this age of sets they were bypassed? and needed a separate one in-line. anyway unless there is some impedance problem the thing works but I don't think its how the moving coil speaker should sound. It's quite shrill and lacking any colour, more how I would expect a cheap moving iron speaker to sound than this one. Its better at low volume and doesn't exactly blast at high, just distorts, its a bit weak sounding so it may be the radio or the speaker. I need to try an external speaker, but presume that should be a high impedance one, and I've only got a horn I think

[geofy]

I am not to familiar with reed type speakers. Has the original speaker which may have been a reed type been replaced with a moving coil of totally different impendence, this would explain why it doesn't sound too good if the set is designed to drive a reed type. If the components in the set are working it could be that the speaker itself is faulty, a likely symptom of what you describe can be caused by the speech coil being stuck, maybe due to rust around the pole magnet. A suitable temporary speaker will tell if the audio output is working correctly. One 'problem' when using a digital source in any vintage amplifiers is the digital source has a much wider dynamic range and could potentially damage components that where never intended to reproduce this type of signal.

[chipp1968]

From what I have ben told recently it appears the British version of this set uses my speaker and the continental ones use the reed speaker . Its definately a phillips type speaker in mine as I have been looking at pics of other models .
The possibility of the pole piece sticking has already crossed my mind , but i wont know till i find a suitable test speaker . A freind of mine bought an unrestored Murphy A70 at harpendon bring and buy which had a siezed speaker and when freed the set actually worked perfectly !!

[geofy]

The bakelite attachment to the speaker is, I am assuming, an output transformer, in which case you will have to go on the secondary side of this with another speaker.

If you can remove the speaker, a simple test can be made by gently tapping the cone with your finger, it should make a sound like a small drum being tapped, resonant, if it sounds flat then the cone is likely to be stuck. A small battery across the speaker contacts will show if the cone is moving but only make a brief contact each time.

[chipp1968]

Thanks ,stupidly i didnt think about connecting another speaker from its own tranny I will have a look at it on saturday , I wanted to clean upthe case then anyway.As the speaker is working then it must be moving so i dont think the battery test will be usefull ,i suppose its possible its partially moving but not its full motion , though there is no sound of rubbing except if i run it at full volume or occationally on loader passages . so it seams to need attention anyway .

[PJL]

It looks in superb condition.

I haven't tried my 834A on a CD but distortion is quite bad on radio due to the anode bend detector. As the gram input does not change the bias I would not be surprised if it is distorted too...and the speakers have no low frequency output - I read somewhere they couldn't make powerfull magnets then.

There were high quality sets in the early 30's - only this wasn't one of them!...Peter

[chipp1968]

yes my murphy A8 produces surpurb quality sound from my i pod ! This is why im asking as the philips is "rubbash"

[geofy]

Spelling aside An early Philips permanent magnet speaker is capable of very good sound, it shouldn't be expected to have the deep bass of a modern speaker, as it has just a paper suspension and pressed cloth/paper/paxoline centring spider. But it will be capable of a reasonable and acceptable bass response, and the Philips speakers of the mid thirties also had a parastatic plastic tweeter cone fitted to the central spider screw. Quite an innovation. I would personally only use an iPod with a proper docking station, not an old timer. Then again I am unlikely to buy an iPod.

Geof

[chipp1968]

Yes i would expect it to be a bit better than it is .
I use an ipod as a sourse of music ,which is what its for .I dont see it any different than connecting a period 1932 record reproducer as a source of sound. would you perhaps connect a casette recorder ?

[geofy]

Hi Chipp
It could be that you are getting a mismatch by coupling the output of an ipod to the input of an early radio, if you are using the gram input this will have a load resistor across the input suited to a gram pickup of the period. Also digital sound has a more dynamic response and could send potentially damaging levels to the old fashion amplifier. If it where mine I would only use it in conjunction with an old gramophone playing 78's. A cassette recorder output would probably be more suitable. We shouldn't expect these old radios to perform like they where brand new. A bit like taking an old Austin Ruby (from around the same period) and sitting it at eighty (sorry officer, seventy)on the motorway for mile after mile, not what it was designed for, not that it could reach that sort of speed!

Geof