advertisement


DIY FB1i anyone?

I'd also say I'm sure if I really noticed any change swapping the resistors to mills, so you may want to try "bog-standard" cheaper resistors first. Have you got the drivers yet? (I'd be interested to know the part number of the tweeter...)
 
James Evans said:
I'd also say I'm sure if I really noticed any change swapping the resistors to mills, so you may want to try "bog-standard" cheaper resistors first. Have you got the drivers yet? (I'd be interested to know the part number of the tweeter...)
Click to expand...

I think its a Vifa D27 in the '+' version?

Another source for crossover caps and parts is Wilmslow (despite the appalling site).

I would second JE's suggestion of rebuilding hardwired, rather than trying to salvage the PCB.
Click to expand...

Im fammiliar with Wilmslow, agreed about their site....

Im considering salvaging the PCB to be honest. What im considering is using a resin compound to fill in the space between the PCB and terminal plate. I saw something simmilar on Jhon Eekels site I think? Obviously I wouldnt do this until any necessary tweaking was complete.
 
fatmarley said:
Mike,
That crossover was a great find! I didn't think you'd find one in a million years.

Mundorf and Mills resistors can be bought from www.hificollective.co.uk
Click to expand...

Cheers Matt. I was really lucky there.

Just need to buy drivers and build cabs now (and repair the networks).

I think I'll have the front baffles made by wilmslow (Who else does bespoke cabinets by the way?) and build the rest myself. Should be pretty easy to do.

Are PMC using a 'special' damping material?

m_d7299841b2c41ebe2cd0ebb89fee52b3.jpg
 
Stripped down the crossover with the worst damage to inspect....

Bad news is that one of the traces is broken (but easily repaired if I choose to). Good news is the Coils are marked with their values which means brand new crossovers could be built with sexy Coils.

Here are some pics:

l_d071d6747b94f0034265825f471a9f88.jpg

l_b1daf839c3717c8e333445c04a52574c.jpg

l_ff95a12e8b6ef96095417c7af685bae6.jpg

l_e8aa4334afaff53842b7ba861a47fe9b.jpg
 
In the photos above the coil on the left is marked 1.2, on the right one is marked 0.9.

Is there anyone out there skilled enough to draw up a schematic for me using the above photos? All the values should be visible from the earlier pictures.

By the way, the solen cap was defo fried, had a large hole in it.
 
mikesnowdon said:
In the photos above the coil on the left is marked 1.2, on the right one is marked 0.9.

Is there anyone out there skilled enough to draw up a schematic for me using the above photos? All the values should be visible from the earlier pictures.

By the way, the solen cap was defo fried, had a large hole in it.
Click to expand...

Mike, based on the above your xover is:

fb1.gif


quickly knocked up in ppt so boxes for inductors rather than coils, but it should be clear hopefully!

Very similar to the DB1 xover unsurprisingly
 
if you source that pyramidal foam damping post the link here please! Madisound have the shielded version of the original DB1 drivers on offer at $29 a pop at the moment. I'm quite tempted to knock up a cloned pair with the tweeters I've just taken out of mine.
 
James Evans said:
if you source that pyramidal foam damping post the link here please! Madisound have the shielded version of the original DB1 drivers on offer at $29 a pop at the moment. I'm quite tempted to knock up a cloned pair with the tweeters I've just taken out of mine.
Click to expand...

No worries, will post the link when I find it.

The Db1 cabs should be easy to duplicate. just find a reference point and work at the dims from there.

Thanks for the xover scematic.
 
yup, I have all the internal dimensions. The foam is the tricky one - if it can be plain foam and not pyramidal then that makes life easier.
 
Do you mean 'pyramidal' aka Dimple foam? If yes then the stuff is readily available. My only consideration would be getting the same density of the foam itself. Need to do some more detective work....
 
No luck with the damping foam yet. Had a read though and found a few articles claiming that PMC 'have developed a new material' which I dont believe. Its marketing speak for "we tried lots of *ready manufatured* foam until we found one we liked best" Its gotta be out there somewhere.......

2 things seem to be critical with the foam: First is the density or 'weight' and second is the positioning/thickness. It appears that the foam used in the above FB1i pics - directly behind the driver - is flat rather than dimpled (or its 2 peices or dimple foam facing each other?).

As a "plan b" on the foam issue I'm considering Troels Gravesens approach on damping TL's.

http://www.troelsgravesen.dk/cabinet-damping.htm

He uses a combination of some kind of felt material and egg-crate/dimple foam. Obviously I would do this in a fashion that mirrored the PMC layout, and try to keep the overall thicknesses the same as PMC.

In this link to Troels site there are some pictures to illustrate what I mean:

http://www.troelsgravesen.dk/ATR-TL.htm

Any ideas/comments?
 
Hi Mike,

How are you going with your FB1+ build?

I own a pair and I'm looking at building a pair or DB1i for the bedroom, would love to hear how you've got on.

Cheers,
Q
 
Q, do you have the driver part numbers and xover schematic for the i? Be interested to see them if you have.

cheers

James
 
Hi James,

No I don't have the details for the i series.

I do have some pic of the drivers and xover of the FB1+, not sure if I can upload to this site though.

Here are the details of the drivers.

HF - Vifa - D27TG-35-06 6 ohm - 06122004 - www.tymphany.com/d27tg35-06
LF - Vifa - M17WG-09 8 ohm - 09082002 - www.tymphany.com/m17wg-09-08

I've managed to cook one of the LF drivers and the replacement was around the $80AUD mark. The LF drivers are discontinued, but the HF is still being manufactured.
 
Hi gscott.

I havent started yet due to other projects such as my 8 month old baby girl. :D

Keep us posted on how you get on. I know James was interested in diying the DB1.

Mike.
 
You must log in or register to reply here.


advertisement


Back
Top