My Calpamos Build

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#143
I have, though it’s been some time since I did, so this is an older memory. My impression at the time is that the speakers sounded a little thin with the 300B. The Calpamos dip down to 5ohms at about 35Hz. Now that it’s been some time, and the speakers have definitely had enough time to loosen up a bit, I should try this combination again. My 300B amps are also wired for 8R output, so it’s a bit of a mismatch. I haven’t yet installed a switch to toggle the output between 4R and 8R. I have the switches, just haven’t installed them yet. This is likely to be my next mini project.
 
#144
Eric said:
Found it! The crossover is mounted on top of the dampening material. The dampening material has a heavy sheet of tin foil on the top that is coated with paint. The solder joints on the bottom of the crossover are poking through the paint and shorting on the foil, thus “removing” a few components from the crossover circuit.

With the crossover mounted in the cabinet, pressing down in a particular location created the problem. With the crossover removed from the cabinet, I am unable to duplicate the problem. I’ll add a layer of cardboard or thin plywood under the crossovers in both cabinets.

Problem solved!
Click to expand...
Somehow I recognized this problem very early on in my head and came up with a good way to mount the crossovers. Toni mounts spacer sleeves on the breadboards, but the circuit boards also sag considerably from the weight of the large coils. I also didn't really like the way Toni's crossovers were mounted in the Calpamos. After making small changes to the crossovers (positioning of components), I will use additional spacer sleeves in the middle of the circuit boards. I will install a mounting plate in the housing on which the crossovers will be mounted.
 
#145
Eric said:
I've examined the crossover and all that I can find with close visual inspection is this resistor leg that looks like the copper has corroded to some extent. I'll reflow all of the solder joints anyhow.

Does anyone have any commentary of the appearance of this leg of the resistor?
Click to expand...
When I rearranged a few components on the crossovers, I found a Mundorf resistor with a small flaw. They don't like being tightened too tightly with cable ties. I then checked the resistor and it was completely fine. It just looks worse than it is.
 
#148
No, unfortunately not, we have already written to you. I am still faced with the challenge of building the housing. At the moment I am still waiting for the right season and scraping together some money for the wood. Unfortunately everything has become more expensive. But I am very happy to hear that you are still happy with the Calpamos speakers..
 
#151
Well , I'm not surprised actually looking at the boards. For the moment though I will look closer at Cornscala B project 🙂 considering the state of my finances. For a long time already I hoard CAR T3 Boxes with those "wretched" horns. Original design, which I never liked when I had a chance to hear it used TAD TL1601/TD4001/ET703 with an exact copy of TAD crossover they used with TH4001 horn. The speakers got great reviews but what doesn't?. I bought original crossovers from CAR (Classic Audio Reproduction) because they changed the design to Edgar tractrix and Field coil Cd's. TD4001 which I also had I sold becuase I couldn't stand it. Since it's not easy to find something which will just drop in instead of 2380a and lacking the skill for scratch design I will have to find some passable solution .
 
#152
To be fair to Tony, the parts quality of his crossovers is clearly top shelf. The coils include 8g and 10g from Mundorf and Jantzen in order to achieve low resistance. Some of the caps are silver caps and resistors are high power Mundorf. Then, he assembles and tests them before they ship. Completed, they weigh close to 30 lbs in total, so shipping across the ocean is a bit expensive as well.

I've looked at the Cornscala projects as well - they look pretty interesting. I think I'll need a bigger house if I keep building new speakers...
 
#154
Actually, rehashing the old beaten horse subject of 2380a horn shortcomings and solutions of using modern throat less Cd's with lower compression or Japanese users extending the throat of this horn for more lf loading, smoother sound I may try TAD TD4002 which is both , modern throat less design and it has a conical extension from 1.5 " to 2 ". This with the CAR crossovers I have and they are SOTA quality as well and weight a ton . All Alpha core ribbon inductors and Howland caps. They would probably cost more than $2200 If marketed today.
 
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