There's a paucity of information on the Wharfedale Delta series of loudspeakers (Delta 30, Delta 50, Delta 70 and Delta 90).
I can only presume that the Delta 30 postdated the introduction of the Diamond 1 in 1982.
At the other end of the time scale we have the entry-level Delta 30.2 that was made available during 1992/93.
We can compare the two variants here: https://www.hifidatabase.com/Detailed/Wharfedale_Delta_30_5506.php
Click on "Next>>" for the Delta 30.2 offering.
The Delta 30.2 crossover looks none too complicated: https://www.ebay.co.uk/itm/12404946...wkq0GMXNClS/t6R6/j6sokvEbS|tkp:Bk9SR5LY-_GBZQ
I can see an air core inductor and an electrolytic capacitor. Could the the mid/bass driver have been run straight off the speaker terminals?
Click on "Next>>" for the Delta 30.2 offering.
The Delta 30.2 crossover looks none too complicated: https://www.ebay.co.uk/itm/12404946...wkq0GMXNClS/t6R6/j6sokvEbS|tkp:Bk9SR5LY-_GBZQ
I can see an air core inductor and an electrolytic capacitor. Could the the mid/bass driver have been run straight off the speaker terminals?
Yes. The bass unit is much more sophisticated than its humble appearance. There are subtleties which I can't measure and still don't understand. The biggest is that the early, greenish coloured cones always came out best in DBLTs. Marketing was always bugging us to have a black cone like 'other' people.
Swapping the little electrolytic for a film would sound different but not better. It would guarantee the performance for another 3 decades.
This is one of two speakers which had bla measured THD but SOUNDED LESS DISTORTED than more sophisticated $$$ stuff with much better measured THD
The bass unit is also one of my examples of how the break up pattern of a good sounding paper cone differs from the break up pattern of a good sounding plastic cone as seen on a SCanned LAser Plot.
Thanks for the design insight. I can appreciate that the Delta 30 mid/bass driver is more sophisticated than it looks.
My late eighties Mordaunt-Short MS100 "High Definition" speaker employs an in-house, paper cone mid/bass driver that was engineered to roll off smoothly above 5 kHz at an initial rate of 6 dB/octave. This allowed the mid/bass to be directly coupled to the amplifier without the encumbrance of a low pass filter - an arrangement that MS marketed as a "pseudo-active" drive principle instrumental in making the musical performance transparent and "alive".
Wharfedale put out such a proliferation of speaker models in the post XP2 era that the names of many have been lost in the sands of time.
Nowadays, we tend to hear about the long-lived Diamond series to the exclusion of all others. To establish a full genealogy of Wharfedale's output would seem nigh on impossible.
My late eighties Mordaunt-Short MS100 "High Definition" speaker employs an in-house, paper cone mid/bass driver that was engineered to roll off smoothly above 5 kHz at an initial rate of 6 dB/octave. This allowed the mid/bass to be directly coupled to the amplifier without the encumbrance of a low pass filter - an arrangement that MS marketed as a "pseudo-active" drive principle instrumental in making the musical performance transparent and "alive".
Wharfedale put out such a proliferation of speaker models in the post XP2 era that the names of many have been lost in the sands of time.
Nowadays, we tend to hear about the long-lived Diamond series to the exclusion of all others. To establish a full genealogy of Wharfedale's output would seem nigh on impossible.
Thank you all, I've enjoyed learning how my not quite so humble Delta 30s fit into the grand scheme of things!
After New Year I set the Glendale XP2s up in the Living Room and played chirp and pink noise samples through them and the Delta 30s. The Delta 30s flunked the chirp test as there was a definite discontinuity! The Glendales though were good right the way through. I evaluated the pink noise sample using a smartphone frequency analyser app and there was drop off sub 45hz and above 16khz in both, but the Glendales were more even over all. Since then I've listened to hours of variable Classic FM and have come to appreciate a sort of dignified smoothness and power that reminds me of my parent's radiogram. One interesting difference is that my Sony TA FE370 amp needs to be set slightly higher for the same volume as before.
The plan was to recap them, and I did put in an order with Falcon for the required Alcaps, but I haven't received a confirmation for my order, and will not bother to follow up. In conclusion I'm now very happy with the way they sound (and look!) for £80 plus the diesel to collect them.
After New Year I set the Glendale XP2s up in the Living Room and played chirp and pink noise samples through them and the Delta 30s. The Delta 30s flunked the chirp test as there was a definite discontinuity! The Glendales though were good right the way through. I evaluated the pink noise sample using a smartphone frequency analyser app and there was drop off sub 45hz and above 16khz in both, but the Glendales were more even over all. Since then I've listened to hours of variable Classic FM and have come to appreciate a sort of dignified smoothness and power that reminds me of my parent's radiogram. One interesting difference is that my Sony TA FE370 amp needs to be set slightly higher for the same volume as before.
The plan was to recap them, and I did put in an order with Falcon for the required Alcaps, but I haven't received a confirmation for my order, and will not bother to follow up. In conclusion I'm now very happy with the way they sound (and look!) for £80 plus the diesel to collect them.
I really do urge you to replace those unreliable black and red ELCAP capacitors in the Glendale XP2 crossover.
I did so in my friend's Wharfedale E50 speakers which proved to be transformative, particularly in regard to the bass reproduction.
He had been using the loudness control on his amplifier, but after the capacitor replacement the bass firmed up and that was no longer necessary.
I recommend the German made Mundorf Ecap capacitors from Wilmslow Audio that are available in 33 uF, 10 uF and 5 uF values:
https://wilmslowaudio.co.uk/mundorf-electrolytic-ecap-capacitors
I did so in my friend's Wharfedale E50 speakers which proved to be transformative, particularly in regard to the bass reproduction.
He had been using the loudness control on his amplifier, but after the capacitor replacement the bass firmed up and that was no longer necessary.
I recommend the German made Mundorf Ecap capacitors from Wilmslow Audio that are available in 33 uF, 10 uF and 5 uF values:
https://wilmslowaudio.co.uk/mundorf-electrolytic-ecap-capacitors
At what frequency was the discontinuity?
Very little to go wrong in Delta 30.
- The treble unit might be out of phase
- The capacitor might be dead
I'm tempted to say something about the designer of Glendale XP2. He wanted to achieve just that 😉
The chirp test seemed to start pretty low, but the frequency analyser app did suggest it was dropping off down there. Anyway, it turns out that Falcon Acoustics have taken my money, so I'll take that as a sign to chase them up. At £28.84 all in, it's almost rude not too to find out if I can hear a difference
I hadn't consider that there was anything wrong with them, so just thought it mildly interesting - it was just a blip and will investigate futher once they're set up in the basement.
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It turns out that if you misstype your email address - you don't get a confirmation email or anything else until you chase them up, when you get an almost instant response. My capacitors are in the post and should be with me tomorrow - brilliant service!
Do let us know how the recap goes.
You could start with one speaker and compare it with the untouched one.
You could start with one speaker and compare it with the untouched one.
I did recap some warfdale speakers from my father (Linton XP3) with the same kind of caps on the crossover. They are high ESR elco's, so if you repalce them with low esr elco's of filmcaps, you need to redesign the crossover with the old as guid (for slope and crossover frequencies), otheriwise the sound will be off. You will have to attenuate the tweeter more than with the old crossover, and probally put some resistor on the parallel caps of the woofer to get the same filter. Just replacing those old high ESR caps with modern caps without measuring and adjusting the rest of the crossover is a receipe for bad sound.
We are talking about replacing those unreliable ELCAP electrolytic caps with reliable ALCAP electrolytic caps - not film caps.
If the sound doesn't improve I will eat my hat!
If the sound doesn't improve I will eat my hat!
If the sound doesn't improve I will eat my hat!
That's some serious indigestion hanging on my perception of improvement - or lack of!
Capacitors are here, first crossover is exposed and at my mercy, and I'm about to toy with molten metal...
According to Falcon Acoustics: "A loudspeaker which has been voiced using ALCAP capacitors, or where ALCAP are replacing ELCAP capacitors, will remain true to the designer's intended sound character."
I don't know those alcap's, but i don't trust vendors on this. They mostly talk about what earn them the most. But if the esr is similar, than it can be good. You can try them if you think it' good, but ifnot, you will have to solve it different.
It's hard to know what the origina est was of the elcaps that went bad, so measuring your speaker would be good anyway to know. Modern caps have often a way lower ESR, especially film caps. If those alcaps are made to replace elcaps, they probally also kept the ESR similar (or they should have at least).
It's hard to know what the origina est was of the elcaps that went bad, so measuring your speaker would be good anyway to know. Modern caps have often a way lower ESR, especially film caps. If those alcaps are made to replace elcaps, they probally also kept the ESR similar (or they should have at least).
To be exact:
The 4.7 uF ALCAP is a low loss version equivalent to the 'ELCAP LL' capacitor version. This may be an advantage when used as the series feed to the tweeter.
The 10 uF and 33 uF ALCAP capacitors are equivalent to the standard 'ELCAP' capacitor version.
Well I couldn't measure a difference with a smartphone app, but yes they do sound livelier with a lovely smooth and powerful bass. Galu's hat survives to be eaten another day!
The discontinuity in the chirp on the Delta 30s was on the stream from the Roberts Radio as it happened again on the Glendale XP2 testing - this time I spotted it on the radio display.
Very happy with Falcon Acoustics service and the Alcaps, though surprised to find that the 4.7uF was the same size as the 33uF.
The discontinuity in the chirp on the Delta 30s was on the stream from the Roberts Radio as it happened again on the Glendale XP2 testing - this time I spotted it on the radio display.
Very happy with Falcon Acoustics service and the Alcaps, though surprised to find that the 4.7uF was the same size as the 33uF.
Falcon Acoustics only state that the low loss 50 V range capacitors are larger than the standard 50V range capacitors that is being phased out in favour of the 100 V low loss types.
I can only suppose that the larger size is a consequence of the construction technique required to achieve the low ESR (Equivalent Series Resistance) and "high ripple current capability".
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