AirTight ATM-300 - new Coupling Caps
So I want to replace the coupling caps in my Airtight 300B amp. The original ones are $5 Sprague orange drops. 0,1uF interstage caps between input tube (12AU7) and driver tube (12BH7A) and 0,47uF between driver tube and 300B.
I love the amplifier, it is very resolving and airy with great soundstage separation. However I miss some body and fullness, and tighter bass, hope new coupling caps can help with this. I like a natural sound with lots of body and texture, good detail and a tight and deep low end.
I have read alot of forum posts and narrowed my choices down to these 3;
Duelund CAST cu sn tinned copper
Jupiter copper foil paper and wax
V-cap ODAM
I have read that some capacitors are best used in lower voltage applications and others are better in higher voltage applications, so I am open to using different brands in interstage/300B coupling.
Please share your experiences, impressions and recommendations. Not necessarily with the Airtight, but preferably used as a coupling cap.
I generally agree with your points, and I'm no speaker designer, but I wonder how crossover caps could always be totally neutral. For instance, if you replace a factory electrolytic with an equivalent film cap, won't the film cap's lower ESR by definition give the frequency band it's in a slight boost?
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Dear @salectric " No capacitors is perfect. "
YES, the best cap is no cap in the same way that the best fuse is no fuse and that's why I take out all the fuses input electrical power in my electronics. Yes, it makes a change for the better.
R. |
Dear @devinplombier : I'm with you. No cap is totally neutral and electrolitic cap behavior is diffirent that the film ones. In the case offf my speakers that are really old/vintge ADS L2030 ( fantastic silk dome drivers in the tweeters and mid ranges,. ADS made its own drivers in all its speakers but the 2030 that were made in exculive for ADS by a Germany manufacturer. ) ) the crossover original caps for the woofers were an electrolitic ones ( 100uf. ) There are several alternatives coming from Sprague, Vishay, Kemet and the like . Instead I choosed film caps Wima MKP10 wired in parallel to achieve 100uf and performs better than ever but we have to consider that I'm talking of the bass frequency range where what you said you just can't be aware of it .. R. |
@rubjel , Tinned copper Duelands. The othere cap that is very organic but no longer made is the Jensen copper foil caps. Very organic sounding cap. Jensen was bought out by a conglomerate who discontinued these caps. As long as you are in there you can also take a look at the plate resistors on the input tubes. Most are either carbon or flame proof metal oxide used for reliability. I replaced them with higher wattage MiLLs wire wound audio grade. You will lower the noise floor a few db as well. |
