#291
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On the N-800-F there are two caps: a 10.5uF and a 4uF. Typically with most modern film caps you would do a 10 and a 3.9.
I've been buying Soviet surplus caps for my crossovers over the past year: MBGO, MBG-CH, and KBG-MN. The red ones are MBGO 10 uF. They are small for their capacity and are pretty good. The hammertone silver ones are MBG-CH and are same family as MBGO but are larger for the capacity. Both are wax, and I think paper/poly dielectric. The -CH have improved HF response and are a lot bigger.. the silver cap is only 4uF. The KBG-MN are even bigger and are true WPIO. I have the MBGO bypassed with a Vitamin-Q and the HF cap is bypassed with a Duelund Silver CAST bypass cap. The inductors are air core dipped in organic beeswax WPIO and are over a wood dowel and clamped down. I didn't like the idea of those huges inductors being free to move around. BTW The HF inductor shouldn't be a super big gauge and similar DCR to stock. The LF inductor of the same value should be as big of gauge as you can go since it is in line to the woofer and any voltage drop lowers bass output... I'm sure it's not much maybe a fraction of a dB. You could do a really nice cored inductor too but air core should be better if you can get a big enough one to keep the DCR low but then they do get expensive. Quote:
Last edited by junker; 04-25-2017 at 12:06 AM. |
#292
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I replied to this almost a week ago, but I guess it wasn't up to snuff for the moderator? Oh well. Anyway, thanks for all the help Junker. Here's a top shot of my Garrard with that black walnut veneer I mentioned in case you get the gumption to make another set of Altec cabinets.
instagram.com/p/BTSdAbflR1x/?taken-by=mistergrantray Last edited by jdandy; 05-01-2017 at 11:12 AM. Reason: active link to social media like Instagram against forum rules |
#293
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Oh wow you are right that veneer looks awesome. It would be incredible on speaker cabinets!
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#294
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FYI. There's a sweet-looking pair of Altec A7's on CL here in San Francisco. Don't know the guy, but it looks like he modeled the cabinets after the custom set Stokowski had built, which Jeff Day bought a couple of years ago. His list of drivers and crossovers sound pretty dreamy, but he didn't post any interior shots to back up his claims, or show the condition of the components, so who knows. Might be why the price is so cheap?
Just do a search for "Magnificent Altec A7 speakers." If I didn't already have my 846As, I'd be running over to his house to verify those drivers/crossovers are legit. |
#295
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So I've finally gone ahead and installed the denim insulation in the 604s. That stuff is a really great value. $36 for 6 rolls with free shipping to my local Home Despot. Just went and insulated a side, a strip up the middle back, and the top. Similar to how the Flamencos are covered but without the nasty fiber glass. Junker approved!
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#296
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Are you digging it because it's an easier material to handle without affecting performance? That'd be my guess, because fiberglass insulation on skin is clearly worse than Chinese water torture.
I can't really see the new insulation making a noticeable difference in how the cabinet allows the driver to perform, but I'm happy to be wrong. |
#297
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I build my 604 from scratch so I needed something and normally I use 10mm wool Filz Felt ($$$). The denim is affordable, effective, easy to deal with, and easy to cut or even tear with your hands.
On my Flamencos the fiberglass didn't have good coverage... and I rebuilt my backs. Plus I don't like handling it and don't want broken fibers getting into the speaker. Last edited by junker; 05-13-2017 at 12:56 PM. |
#298
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Sweet. So I can add that denim to the list for if/when I rebuild the cabinets. In the meantime, I just finished building the stands for my 846As and am waiting for the Chinese ink wash to dry before I cut felt tops to be mounted with double-stick tape.
After that, I just need to remove the bases on the cabinets and heft 'em up. Quote:
Last edited by grantray; 05-10-2017 at 11:49 PM. Reason: bad flickr links |
#299
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Wow! Those came out great. Did you drill holes on the top layer and then glue two 3/4 layers together? And hairpin legs worked out very well Imo! You're using felt cloth or the adhesive stuff? I completely regret using the adhesive type for something because I could never get the glue residue off.
I'm still in shock at how well they came out and match your decor! |
#300
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Thanks! I'm using small sections of double sided tape and felt cloth cut to roughly 1/8th trim of the edges. The ply is indeed two sheets glued to together. I didn't feel comfortable with using wood screws to hold nearly 100lbs per speaker, so I doubled up the 3/4 ply, increased the tops ply's hole diameter, and used brass bolts/washers with locknuts to keep everything tight and stable.
I set the 846As on the bench to A/B test them against DeVore O/93s, which I've since sold. It was no contest. The horns demolished the Ape's tweeter. That bench height put the horns just above my ears, and about 1-2 inches higher than the the tweeter on the O/93., and the way sound fills the room at the placement is pretty mind-blowing. I also doubled up the 3/4 ply to approximate the solidity of the walnut bench. The Altecs sounded so good on the bench, I wanted to match that with the stands as much as possible. I'll get the speakers up on the stands this weekend, and after that, move on to figuring out what 2A3 or 300B Bottleneck kit to build so I can get over the chasm of building electronics and translating schematics to working components Last edited by grantray; 05-12-2017 at 10:58 AM. Reason: broken flickr links |
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