Electrostatic speakers: Quad ESL 57: resistor and cap replacement with comparison
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- เผยแพร่เมื่อ 13 ก.ย. 2024
- Patreon page: / solveelectronics
Today i decided to replace the resistors and capacitors inside the transformer of my Quad ESL 57's. What do you think?
I have often repaired these. You just made them sound tinny, not clearer and those parts aren't appropriate. Nothing wrong with any of the original bits if within reasonable value. I do prefer the sound of later blue ceramic capacitors to the earlier brown ones but not a big deal. Never found replacement sourced ceramics quite as good. If I were to attempt a tweak, I'd use nonmeagnetic (close to a transformer), noninductive metal resistors (Mills?) and find some (large) polystyrene capacitors of correct value and squeeze them in or raise the transformer a bit to accommodate.
Point is, Quad got it right and it will take more effort to try and make it better. Probably also involves trade offs since the device was voiced with what what was used. I've heard these modded with VG quality metal resistors and PP caps and they sounded worse to me.
Also, tape that rear dustcover with the thinnest packing tape you can source and tighten with heat only enough to take up slack. Those should not be tighter than just not flaccid. Better a minor wrinkle than to over tighten a woofer panel. Tweeters should be taught. I know some will say I should be telling you to replace the cover but if you do it carefully, you won't notice the difference. They're called dustcovers for a reason as dust will foul the panel and I guarantee it rattles at times like that. It's not a passive process. There's an electrostatic attraction for dust.
Well, they sound far better than they did, and the video doesn't do the sound any justice, as they are very colourful and full bodied. I didn't try to make them better than what they were, that wasn't my aim. My aim was to bring them up to spec as the values for almost everything was out. Of course, it would have been better to have quality resistors, but those were also direct replacents and recommended for replacing them
@@SolveElectronics It's all relative. Glad you like them.
"If within reasonable value" is the key thing here. I replaced the crossover resistors of my ESL's many years ago. It turned out that the old resistors had drifted by 15 to 20% which is unacceptable for a crossover network. Before, the speakers had a noticeable difference in sound, and that problem completely disappeared. I wonder how many ESL's are sent for repanneling, where a simple resistor replacement would have solved the problem.
Massive difference from where I'm listening. The worked on speaker sounds louder and much clearer than the one with original components. The bass comes across at a higher frequency and less low frequency bass response. But the mids are definitely clearer that is what I think. Do I like the sound of the upgrade........s👍🏾
Really useful, I have the resin EHT boards as well. Liked that music you played.
Hard to tell the difference on TH-cam, but as soon as you upgrade the caps and resistors the 57 comes to life. I found polypropylene caps and metal film resistors to have a clarity that was so far ahead of the old components it wasn't funny. That combined with new Mylar film diaphragms increased the sound output significantly. Twin stacked quads are hard to beat. I have never liked the sound of carbon resistors and have always replaced them with metal film in my amplifiers.
Definitely true, it is hard to tell, which is a bit sad! But they definitely come through. I should look at them again in some time, as one side treble is quieter than the other, and the bass is more pronounced than the other too
You might want to try audiophile quality low induction wire wound resistors and better caps. You don't need to spend crazy money to beat sand cast resistors and ceramic caps. When the bass output increases, mids and highs might sound lower due to the relative sound level differences. I loved those speakers when I first heard them in person. They are amazing.
Thanks for that info! I found it hard to get the resistor and caps I wanted so I just went for those. If I could have found some really good one, which I was hoping for, then for sure I would have gotten those, but I just couldn't
By the way: "Ceramic and carbon composition, not to be confused with carbon film, are naturally non-inductive because they don't have any windings" so I think it's fine to say they're fine to use, but I should find some better quality ones for sure!
Only way you can tell is frequency response test with a standard special ultraflat response in a nutral sound proof room you have wooden flooring not many heavy draped curtains
On another note, Are you using the rear damping? I noticed that the tweeter panel specific damping was not in the shots and normally stays attached when the back cover is removed.
Yes
Great sound from the one with new resistors. I bought a pair of original, unrestored Quad 57's yesterday and one has half the volume. Any ideas what would cause this?
Leave them to run for a while. It can also be the eht board. One of mine was also quiet and I replaced them. They made a massive difference. You can find the board at onethingaudio. Check my other video on these
@@SolveElectronics Yes, I'm going to try a new eht board. I hope this is all it needs.Thanks!
Those old resistors are carbon, you replaced with ceramic Wire Wound, I would have purchased a complete new pcb from Quad
Now I looked in the datasheet of the resistors and they are rated for 1000 volts so the resistors will also selfdestroy after some time.
They're 5w resistors and the ones that were in them were 3w, so they should never breakdown
@@SolveElectronics Sorry they will break down. Look what other people use that repair ESL.
@@franswouters3390 I'll have a look 😊
@@SolveElectronics You needn't worry that those resistors will break down, because it is the resistance value and power rating that determines it's maximum voltage handling. This link explains it well
seielect.com/news/20170821_-_Resistor_Data_Sheet_Information.pdf
Personally, I would not change those resistors or capacitors unless they were not measuring in spec ( within 7% tolerance ). Those components are more likely to have been damaged if the panels had been arcing. If any of the panels showed signs of that, I would check their values. If they were ok, I would leave them alone. You would be better off replacing the dust cover on that bass panel. I'm sure you have already seen this repair guide.
www.pearl-hifi.com/06_Lit_Archive/07_Misc_Downloads/QUAD_ESL-57_Rebuild-Mod.pdf
The dust cover being damaged can affect the sound.
Hope this helps
@@mikw1809 thank you very much for the information, every day is a learning day! I will look into that. Thank you
Please! Take off these bad cement resistors! They are not for audio at all.
Your new capacitors are 3KV "DC" the original capacitors are 4KV "AC" so after some time your new capacitors will be destroyed.
Ah shoot! Well, I'll look into finding some new ones!
Sorry but this “Restoration” is vandalism, really. Do find some inferior speakers to destroy instead
Glad you're enjoying it. For those looking to repair or upgrade resistors, do not use these types as they will be magnetic and can be affected by the transformer. en.wikipedia.org/wiki/Proximity_effect_(electromagnetism)
For those that are willing to read how things work, this isn't how it works for any resistor. Please delete your comment