The Hi-Fi Build, Hack, Exchange and Repair Thread

I figure I can’t be the only person who has a few things to build and repair, so I figure starting a thread where we can talk about it and exchange parts might be a good thing to have.

I have three sets of speakers that need tweeters right now, and ebay etc is unreliable as a source and tends to have pairs.

Things I am looking for:
2x KEF T27 [black, faceplate wired kind, as fitted to 104aB]
1x Celestion SL600 Copper dome
1x B+W TP-26

Does anyone have any of these?

I have a snazzy crossover to make in the future, so I’ll be posting about that then too.

Feel free to post anything related in here and hopefully we can all help each other out :)

Sam

KEF T27 were these the ones in the B&W DM2’s or were they CF1300’s?

If its the former I have a pair of DM2’s sat in my parents house taking up space you are welcome to cannibalise (West Midlands).

Marantz MP-66 , needs a new source selector switch / dial I think. Might take it apart and use the case to build a valve amp if anyone can recommend a cost effective kit?

Dennon radio receiver, free to a good home?

Heaps of Kef (labelled) drivers on ebay, sure I’d seen tweeters there

There are plenty, yes. Prices vary wildly, and whenever I get around to searching for them the only ones available are stupidly overpriced :D

@ my hippy bud, very kind, but if they’re functioning it seems a shame to take them apart. Are they the Mk1 or Mk2 [handed or symmetrical]?

Just let me know if anyone’s got a pair on here :)

Does beg the question “What on earth are you doing to your tweeters?” doesn’t it.

Either you have young kids sticking pencils in your speakers, your amp is underpowered & clipping, or maybe you just LOVE IT LOUD?

Might be an idea to be more careful with them When they’re repaired!

I need a pair of speakers. I got rid of my Tannoys a few years ago, took up a bit to much space[so I am told]. I now find myself speakerless, and playing through the computer is pretty dire.

Haha, yea, well the story is this:

Until 15 years ago I used my dad’s old gear.

The 104aB’s were killed by a Mix CDR a friend made – I whacked it on for the first time, turned it up to a loud but safe volume and got in the shower. After 15 minutes, one track came on hugely louder and more distorted. By the time I got to it, both tweeters had died :( He’d long since replaced the KEF’s so I just left them. Feeling a bit guilty now, trying to help him fix everything up so he can clear some space, he’s got a lot of gear around.

The B+W’s were me, straight-up. Killed them with a hall party at Uni [the first time], got so drunk I didn’t hear the distortion :/

The Celestions, my dad. The tweeter was covered in crap, so he wanted to remove the metal cover. He started by removing the three screws around the dome to take the tweeter our of the cab, but they actually held the magnet on. It came lose and fell, shearing the coil off.

Just trying to tie up a lot of lose ends.

EDIT – Yes I love it loud, but I actually have very good hearing [tested in an anechoic] Currently using <320W RMS, but am spread out over 2 amps. There’s spare channels in the amps, hence wanting to build a crossover to just use one of them

@integer – describe the space they’ll go in, the room and the kind of music you like and maybe someone can help you out. Also – your location.

Personally, I buy most stuff from cash converters etc.

Here’s a list of classic Hi-Fi to look out for :)

The speakers I am fixing are all spoken for now, but I’ll tell you if I find anything.

MK1’s I think not sure how functioning they are I had two pairs originally one that I gave to a friend and then these are left, and the cabs have seen better days.

Currently taking up space and I have two pairs of MS 1970’s speakers that are more than space occupying enough.

Are Wharfedale 420 speakers worth saving? I have a pair sat taking up space, I got them as part of a gumtree job lot. Free to anyone who comes to Doncaster to get them.

Currently using <320W RMS

Are the speakers you are using capable of handling watt (sic) you are throwing at them? Sounds not if you keep breaking them.

Yes yes. Not broken a speaker in 15-odd years, I wrote what happened above.

80W x4 now, for MA BX2’s and a dual B139b’s in a folded horn sub. It’s all good.

@one_happy_hippy – I don’t think the tweeters are T27’s, just whack em on gumtree or maybe someone here will want them. Thank you very much anyway :)

http://pho.to/9a51Y

http://pho.to/9a522

http://pho.to/9a52d

Old, but good :)

‘Sup?

Been a bit busy with the sub. I finally fully understood the design and was able to make some simple mods:

1 – flip it on it’s side
2 – remove the sleeping bag and replace with carpet lining and a couple of little wads of tightly wrapped fabric sort of smooth the corners in the cab.
3 – flip the drivers
4 – carefully stuff the last tapering part with hollowfibre to an even and fairly tight fill
5 – remove the rabbit from the mouth of the horn

I didn’t stretch the carpet across the mouth of the horn, that seems odd to me.

Sounds good, faster and with more slam. More even response too, though my listening position has a huge suckout around 45-52Hz, nowt I can about that :/
response is now pretty even from 28-80Hz, apart from a few ripples. Next – get a job and buy/build a x-over.

Is that a house rabbit?

One of two.

Wow, more pics please!

Yeah….. let me find a rabbit thread to ressurect ;) *

Meanwhile, look what’s been going on in the world of Cable Bullshit Bingo!

AudioQuest HDMI Cables

* cinnamon – TBH I can’t be arsed to upload several pics and I don’t have an open rabbit appreciation thread. You can look at all the bunny pics I have ever taken if you wish – add me on FB with the same username as here.

@gofasterstripes; thanks for that link, fascinating reading! The truth would be out there, if it wasn’t bad for enterprise!

BUMP!

I’m going to be repairing a Cambridge Audio Azur 540r fairly soon, will post pics. Bulging PSU caps and DC offset :(

I have slightly hacked my setup again, now using the sub’s B139s in series with the low-pass terminals on the back of my AE109’s, and then those in parallel with the Mid/High section. Seems to work OK and means I’m able to get by on only a single amp while one of them is out of action. God knows what the x-over point is but it seems to work quite well considering I just doubled the impedance the low-pass x-over is designed for 8O

Going to order a MiniDSP later today to use as a digital crossover. It going to be taking PCM stereo SPDIF in and needs to output either 1 SPDIF with a 6-channel encode for my amp’s internal DAC, or, I could use a DSP that outputs 6 analogue and just use the amp as a Poweramp alone.

The choices for the DSP are still a little confusing… I want to keep the audio quality at 100%, obviously, and some formats sounds better than others. The Amp is Rev2 CA Azure 540r, and I was planning to use DTS audio out from the DSP…. If possible.

Anyone got any experience or thoughts about how to do this?

https://www.minidsp.com/forum/minidsp-for-newbies/13511-dsp-for-3-way-speakers-av-amp-and-pc-dvd-phono

Outbound link for DSP forum and full details of question.

How not to save money by buying second-hand speakers….

Now most people would buy the Diamonds… but I have a soft spot for 70? Technics Speakers

…more to come ;)

Well, when we went to test them, they were shot… but for 10 Euros, I could have a cast aluminum box, and that? got to be a good start for a project, right?

A unique, super low coloration, ultra-dead, acoustic suspension project ;)

So:

They came home with me.

Let? have a look inside shall we?

Cute…

…but b0rked.

However after consultation with the lovely guys at Speakerland Oss http://www.speakerland.nl I returned with:

and a simple filter [bass:choke/treble:2nd order + series resistor]

Hmmm…

Hmmmmmmm…..no

Yes! But tricky. Need to chop the studs around the tweeter off and mod the bass driver.

So. Onto the build:

First, chop, sand and prep the cast aluminum cabinets:

(oh did I not mention the Hyster Yellow paintjob?)

Next lay your parts out and prep your equipment and tools:

I started by making templates for the 650g of ripple-finish lead for the cabs, including cutouts for the crossover and crossbrace (another mod I added)

Assemble crossovers:

Where? the bicycle angle I hear you ask? An iinnertube+double-sided tape cabinet seal:

Triple-check clearance and get medieval on it? ass:

(note precautions against getting filings in the driver, which has a vents BEHIND the spider, so bits could fall straight into the magnet gap)

Nice.

So, we need a seal here too:

(yes I trimmed the ends)

Yeah! It all fits!

Now, add a little acoustic surface treatment ;)

(slightly tidied after this pic)

Some long-hair wool, about 25g/cab (smells good :) )

(NB terminal block used for XO phase testing, will remove/direct solder later)

Screw together, real tight. Check airtightness: Drivers take seconds to return after being depressed.

Place on the end of 100w and run-in. Note 1.75m TQWP sub for scale (not connected).

Add a little EQ (ball park at this point) as the horns are boosting these freqs.

(nb +12 is neutral for the VLC preamp)

ENJOY THE DIMINUTIVE BEAUTIES!

Listening:

Pros:
*Clarity
*Micro-dynamics
*Width of soundstage
*Power handling/volume output vs size
*Smooth bass rolloff with surprising depth
*Very little vocal coloration including on female voices
*Very tuneful bass

Cons:
*Strong peak around 3kHz
*Efficiency
*Listening position/toe-in very important
*Upper treble somewhat rolled-off

Next Steps:
May address the peak with an improved filter, or, in software.

Overall:
Built, hacked and repaired SB-F2 –> SF2 (my second handmade speaker)
My back hurts but a really fun way to spend 36hours ;)

Advice needed – I have been offered a Project Debut 2 turntable from a friend for £40, I know he will have looked after it and its recently had a new cartridge. Anything I should look out for and tips on setup/cheap mods?

I’ll also need a phono stage but they seem quite spendy, any ideas?

my failed attempt at repairing an old arcam delta 290 amp.

so…. ill be putting it on ebay soon as spares/repair as the superfi bod told me theyre still in demand when not working. dont know if the fact ive cut into the selector will mean nobody wants it now but i was only going to scrap it anyway.

also have decent old yamaha cd player and denon tuner if anyones interested in owt…..

dont really understand hifi so dont know what a phono stage is but i have a pre-amp that used to be needed with a turntable too if thats anything like you need robdob?

Yes a phono pre-amp. Signal from a TT isn’t strong enough for a normal line input, modern amps don’t tend to have a phono pre-amp built in like old ones did so you need a seperate amp.

I need an amplifier to complete my dining room system, have a nice sony CD player and picked up some lovely little gale speakers off freecycle for £0 in mint condition but I don’t have an amp.

not interested in bluetooth/multiroom/wifi stuff!!

These pre-amps sound good and will get you going before you spend £££s!…

https://www.amazon.co.uk/Behringer-PP400-Microphono-Compact-assorted/dp/B000H2BC4E/ref=sr_1_4?ie=UTF8&qid=1504870922&sr=8-4&keywords=phono+preamp

@sadexpunk

You’re saying the speakers on both amplifier outputs work when the amp is in mono mode but not in stereo mode?

This would appear to be a fault with the switching, yes. Have you tried googling the numbers printed or stamped anywhere on the input selector switch, on the metal casing or on any of the internal switch units? It may be a very cheap little bit to replace, if you can find the part.

yes mate, mono but no stereo. ive updated my thread and youre quite right its the selector swich. tried everything, emailed arcam and had a reply saying they dont make the switches any more and the amps more than likely borked due to age. said i could pay £60ish for a service and itd happen again in a few months so i tried cleaning it myself but it hasnt worked.

thanks

I’ve got a pair of Eltax Monitor 3 speakers and a Sherwood AV receiver RD-6103R up in the loft. Pretty sure I’m not going to use them as they have been up there a while and don’t tend to sit and listen to music at home. Where is the best place to move on with least hassle? Are they worth much these days?

@gofasterstripes

Wow, Great job!

Nice work on those little speakers! Very impressed indeed. :D

Nice work, but why sealed to the point they take seconds to return. That’s some cone damping. Why not a bass port so the cone moves freely? (says the guitarist who uses both open-back and closed-back cabs and knows how subdued closed back cabs sound compared with open or ported.

The boxes are designed to be airtight, rubber lip seal and all. The original drivers were also very nicely sealed in, so I figured I’d just replicate that and see what I got. Also, they’re intended to be the PC speakers, so they’re intended to be used close to a wall.

Turns out with this speaker, it’s not dead sounding, certainly not around voices or guitars. But then this is quite a different combination of parts to your guitar amps: these woofers are glass-fibre cones with rubber surround. The guitar amps I have seen use large boxes with paper drivers and cloth or doped paper surrounds, and whose drivers displace a lot of air. So I imagine the effect is quite substantially different in terms of interaction. Eg, the cones take a couple of seconds to return when depressed several mm, but only bass notes below, say 100hz, get anywhere close to that level of excursion even when playing very loudly, so it’s significantly damping the bass but not the mids, that’s where the enclosure does more I think.

I’ve not even really begun tuning them yet, more wool, different cap for the tweeter and the mini DSP, all or any may yet be employed;)

I’ll let you know how it goes, so far the response is a bit lumpy but the quality of the sound, especially the insight around the mids is stunning… Not sure if my BX2’s have much of future now!

@CZ/Jamborgie : thanks !

After some more listening, and a little dabbling with this puppy:

miniDSP 2x4HD (comes highly recommended, very useful for hi-fi hacking, these)

I have an awesome set of nearfield monitors!

You can’t just stick a port in an IB design (did you get woofers with the right parameters for the box volume?) because the drivers need to have completely different parameters.

Unless you work for Bose or Sonos :P

I think the TS figures are not ideal, but the tone and quality of the driver makes it work well enough. I was pretty limited in time and money, so we chose from what we had available at the time.

They had some new ported designs there with a ScanSpeak beryllium tweeter, those sound totally effortless and detailed :D