Infinity Quantum 2 - High Impedance Readings
- Thread starter MoreBeer
- Start date
MoreBeer
Money + Money =More Money
Good to know. Maybe I'll just order one to see. The old pots can be cleaned although the wiper which makes contact with the coil really needs to be scrubbed with fine emery cloth to get decent contact as the plating of that little nub on the wipers are just about shot. This small contact nub possibly corroding long-term is a concern as I'd rather not rip these apart again. This was my primary reasoning behind getting new pots.
Aside from that, using CRC contact cleaner followed by letting everything soak with CRC c-26 electrical lubricant works great with the other parts. In fact, the coil cleans up like new. This method is superior to just using Deoxit.
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toxcrusadr
Omelette au Fromage
If you replace them, hang onto the originals and/or offer them to someone else here whose pots are worse than yours!
If you can figure out where you like them set, you can replace with a fixed resistor a someone alluded to a few posts up. But if these Chinese ones fit, so much the better.
If you can figure out where you like them set, you can replace with a fixed resistor a someone alluded to a few posts up. But if these Chinese ones fit, so much the better.
MoreBeer
Money + Money =More Money
Think I'm going to replace all the caps as I'm getting some bad readings on a few of the yellow caps. The meter reading below should be close to 3.5 uf but is almost 24 uf. One thing I can't understand is why Infinity piggybacked small .33 uf caps on top of the two larger yellow caps in this image? It doesn't actually change anything? Does it???
The crossover in this image was not as badly corroded as the other for some reason.
Luckily the beer can filter caps are good and well within range of 700 uf and 1100 uf and all the inductor coils check out as well.
The crossover in this image was not as badly corroded as the other for some reason.
Luckily the beer can filter caps are good and well within range of 700 uf and 1100 uf and all the inductor coils check out as well.
The small value caps could very well be film/foil bypass caps
I've read that those big lytics are very good and not surprised they still measure well however ESR measurements should be taken.
slimpikkins
Super Member
Do you have one side of that cap unsoldered? If no you are measuring the resistance of other components giving you a false reading.
MoreBeer
Money + Money =More Money
There's really nothing else there which can alter the reading on this cap. Plus the same cap on the other crossover tests normal at 3.6 uf.
Hi Folks,
I've been reviewing the posts about the QLS-1's for some time and finally bit the bullet to begin the rebuild on my set. My father and I picked out these speakers and purchased them from Lyric HiFi White Plains, NY in 1977. I was 17 at the time and was in heaven. We also purchased GAS equipment to complement them. Over the years I have always loved Infinities and now also own a pair of Renaissance 90's and a pair of Kappa 8's. The QLS's have been in storage for some time but after speaking with magicmarksy who has a rebuilt pair for sale on Ebay, I decided it was time to bite the bullet. I have already ordered all the caps, the chinese pots (a repair shop changed out the original pots with low wattage pots that are worthless), and 25 watt resistors to replace the series/paralleled joke that is in there. I have a good LCR meter and did not find issue with the coils, they measured a bit lower than expected at 100 hz test frequency but Bill Watkins told me that at 30 hz (which I can't try) they would probably measure fine. Bill also said that the coils rarely go bad and that other problems will probably be introduced since replacements will not be compatible.
While I'm waiting for the parts to be delivered, I am doing triage on the drivers. As a quick check,I was wondering if anyone knows what the total DC resistance should be for the bank of tweeters and mids? Also if anyone knows how tweeters and mids are series/parallel connected to achieve that total resistance/impedance? I may like to use heavier wire.
BTW I am trying a couple of expensive Solen "Silver" 2.7 mf caps ($20/ea) for the tweeters to see if that sweetens things up a bit.
Thanks in advance for your responses!
I've been reviewing the posts about the QLS-1's for some time and finally bit the bullet to begin the rebuild on my set. My father and I picked out these speakers and purchased them from Lyric HiFi White Plains, NY in 1977. I was 17 at the time and was in heaven. We also purchased GAS equipment to complement them. Over the years I have always loved Infinities and now also own a pair of Renaissance 90's and a pair of Kappa 8's. The QLS's have been in storage for some time but after speaking with magicmarksy who has a rebuilt pair for sale on Ebay, I decided it was time to bite the bullet. I have already ordered all the caps, the chinese pots (a repair shop changed out the original pots with low wattage pots that are worthless), and 25 watt resistors to replace the series/paralleled joke that is in there. I have a good LCR meter and did not find issue with the coils, they measured a bit lower than expected at 100 hz test frequency but Bill Watkins told me that at 30 hz (which I can't try) they would probably measure fine. Bill also said that the coils rarely go bad and that other problems will probably be introduced since replacements will not be compatible.
While I'm waiting for the parts to be delivered, I am doing triage on the drivers. As a quick check,I was wondering if anyone knows what the total DC resistance should be for the bank of tweeters and mids? Also if anyone knows how tweeters and mids are series/parallel connected to achieve that total resistance/impedance? I may like to use heavier wire.
BTW I am trying a couple of expensive Solen "Silver" 2.7 mf caps ($20/ea) for the tweeters to see if that sweetens things up a bit.
Thanks in advance for your responses!
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Perhaps not heavier but copper wire instead of what's there which I don't think is copper
chef free
Super Member
The 2.85 ohms is just the tweeter array measured at the crossover. If you are getting 7 ohms for the array, you need to reflow the soldier buttons on the EMIT diaphragms. I had a few tweeters up in the 25 ohms range before I reflowed them.
Thanks chef free!
With the tweeter array attached to the crossover with the rear emit switch on I get 2.85 ohms. If I disconnect the green tweeter wire from the board with the big coils on it then I get 7 ohms for the all the front tweeters, I guess I should be getting 2.85 ohms? I saw the thread about resoldering the buttons. I hope I don't damage anything.
With the tweeter array attached to the crossover with the rear emit switch on I get 2.85 ohms. If I disconnect the green tweeter wire from the board with the big coils on it then I get 7 ohms for the all the front tweeters, I guess I should be getting 2.85 ohms? I saw the thread about resoldering the buttons. I hope I don't damage anything.
MoreBeer
Money + Money =More Money
I would up replacing everything in my Q2 crossovers with the exception of the inductor coils. You should probably do the same. If needing to replace any of the mids or midbass drivers, I found excellent drop-in replacements that sound great. Specs are very close to the originals although I'm convinced they improved upon the sound as I did an A/B comparison using one rebuilt speaker with the old mids and midbass and the other with the new. Played a mono signal and switched back and forth. Huge difference. More life, cleaner overall.
slimpikkins
Super Member
The wire in the QLS is tinned copper. Great project you have there, my beleaf is it is not worth changing out the wire, but what the heck do I know. There’s yards of wire in the voice coils too which is there to stay so where does it end. Please if you get a chance take some pics and post them as you progress or maybe start a new thread. All the best Vinny and welcome to the forum.
Yah, I'm changing everything except the coils including the input terminals and the fuse holder. I will have everything this week except the replacement pots. I've resolved the tweeters in 1 speaker at 2.9 ohms and I still have 4 ohms on the other set of tweeters, I have to get it down to 3.
All the other drivers are working. I would consider an alternative driver for the mid bass since I always felt it was lacking but I like the idea of keeping it as original as possible otherwise.
I am really looking forward to getting these setup. I have been listening to the Renaissance 90's for a few years and really love them, but the bass is a bit subdued. I love the Watkins setup in the 90's and the QLS-1's that removes that upper bass peak that most speakers have. I need to relive that QLS bass! I can't take my Kappa 8's too seriously because there is no Watkins bass and has that annoying peak. The other drivers in the Kappa's are great.
When I took apart my Ren 90's I saw that they used heavy gauge wire even for the tweeter so I am thinking to do the same. Definitely heavy gauge for the woofers. It was interesting that Bill Watkins Jr said that Infinity was still learning when they developed the Quantums.
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I will see about taking some pictures. The before pictures would look pretty bad since a "speaker repair" shop got hold of them and made a mess. Kind of ruined the black plastic plate that the pots etc mount on and freakin threw out the 5 ohm pots and replaced them with low watters that failed quickly.
While I was investigating, it occurred to me that the cabinets are made very solid with several cross braces in side to stop vibration, but that plastic crossover mounting plate is very flimsy and must defeat the purpose of the strong cabinet?? I wonder if I should try sealing that off and leave the crossover plate outside as an experiment? I might try that later. I wouldn't know if it's helping with all the other changes being made.
Thanks MoreBeer and slimpikkins for chiming in! I feel like I belong.
All the other drivers are working. I would consider an alternative driver for the mid bass since I always felt it was lacking but I like the idea of keeping it as original as possible otherwise.
I am really looking forward to getting these setup. I have been listening to the Renaissance 90's for a few years and really love them, but the bass is a bit subdued. I love the Watkins setup in the 90's and the QLS-1's that removes that upper bass peak that most speakers have. I need to relive that QLS bass! I can't take my Kappa 8's too seriously because there is no Watkins bass and has that annoying peak. The other drivers in the Kappa's are great.
When I took apart my Ren 90's I saw that they used heavy gauge wire even for the tweeter so I am thinking to do the same. Definitely heavy gauge for the woofers. It was interesting that Bill Watkins Jr said that Infinity was still learning when they developed the Quantums.
.
I will see about taking some pictures. The before pictures would look pretty bad since a "speaker repair" shop got hold of them and made a mess. Kind of ruined the black plastic plate that the pots etc mount on and freakin threw out the 5 ohm pots and replaced them with low watters that failed quickly.
While I was investigating, it occurred to me that the cabinets are made very solid with several cross braces in side to stop vibration, but that plastic crossover mounting plate is very flimsy and must defeat the purpose of the strong cabinet?? I wonder if I should try sealing that off and leave the crossover plate outside as an experiment? I might try that later. I wouldn't know if it's helping with all the other changes being made.
Thanks MoreBeer and slimpikkins for chiming in! I feel like I belong.
MoreBeer
Money + Money =More Money
I don't believe the plastic mounting plate in the back is hurting the integrity of the cabinets. Probably overthinking in regards to that. I also can't see the point of having that big messy crossover outside the cabinets?
These big Quantums are really nice speakers and quite iconic. The only downside is they sound like crap at low volume as they really need to get pushed to sound really good. I found that using a subwoofer helps at low listening levels and I also use an eq preset to boost the highs.
At lower volume, my new system with Klipsch towers and an SVS sub beats the pants off the Quantum 2's....no contest.
These big Quantums are really nice speakers and quite iconic. The only downside is they sound like crap at low volume as they really need to get pushed to sound really good. I found that using a subwoofer helps at low listening levels and I also use an eq preset to boost the highs.
At lower volume, my new system with Klipsch towers and an SVS sub beats the pants off the Quantum 2's....no contest.
Do they wear?
