DIY audio: what are you building?

[mwhouston]

You may not always require a pot. My Cowon S6 has a volume control as does my iPad. So in this case an additional pot is a noisy item you can do without. But you would never use an iPad through the ear piece when you can tap direct into the 24\96 DAC with simple IPad to RCAs connector. This way you by-pass more of the crappy iPad electronics like digital volume controls and headphone amps.

Because now you don't have a volume control you may consider a headphone amp with one. Personally I build my HP amps with no pot and only ever use my iPad for music with my home based AC powered HP amps.

[Guest Muon]

Hmm...The thread that DVP started reminded me that I have a pair of Avondale NCC200 clone PCBs that I populated with the supplied parts years ago, but never finished making an amp.

 

 

There are some things I need to alter on the PCBs first, like separating the -0 of the front-end supply and the -0 of the zobel network that are connected on the clone PCBs. Need to add a R/L at the output also.

A pair of 25v-0-25v @160va should be OK for power.

 

Will be done slowly as I get the needed parts remaining.

 

Edit: Damn! I had a perfect case someone gave me, and I forgot to pack it when I moved back up to Bris'

Edited April 6, 2015 by ortofun

[mwhouston]

@ortofun; I give up, what is it?

[Guest Muon]

@ortofun; I give up, what is it?

Avondale make amp modules based on the 1970s RCA circuit like NAIM do, but they do things a little different, and these are copies of the Avondale ones off ebay.

 

70w or 80w per channel and class B is it? *shrug*

 

They still sell the amp boards on ebay http://www.ebay.co.uk/itm/H-140-Audio-Power-Amplifier-Kit-80W-80W-clone-NAP140-/320622026990?pt=LH_DefaultDomain_0&hash=item4aa68fe0ee

Mine came with the filter/rec boards pre made, bit of a bonus for not a lot of $

 

I might replace the ceramics in certain positions also, before I test. I got the ideas for alterations for these boards from reading builds guys on PFM forum have done in the past.

Edited April 6, 2015 by ortofun

[Guest]

Do it.

Do it.

[St_Luke]

Another stand, this one to better match and compliment the Hd650's

Using a 3 layer and pressed mesh.

 

 

 

 

 

 

 

 

 

 

[Guest]

How many pairs of headphones do you have....?

:blink:

That mesh looks sweet.

Edited April 7, 2015 by Dirty_vinylpusher

[betocool]

You may not always require a pot. My Cowon S6 has a volume control as does my iPad. So in this case an additional pot is a noisy item you can do without. But you would never use an iPad through the ear piece when you can tap direct into the 24\96 DAC with simple IPad to RCAs connector. This way you by-pass more of the crappy iPad electronics like digital volume controls and headphone amps.

Because now you don't have a volume control you may consider a headphone amp with one. Personally I build my HP amps with no pot and only ever use my iPad for music with my home based AC powered HP amps.

 

You might have a point there. My source is my phone, a Sony Xperia, and I can't imagine using a source without a volume control anyway. In any other case, I'd consider a higher quality pot. Lucky for me, removing the pot is a quick fix. I'll give it a go tonight or when I have a peaceful moment.

 

I just replaced the burnt chip, it works beautifully, and the bugger is very loud! Tried it on my Grado's and it sounds really nice. I won't use audiophile's press words like silk and seamless and opening and day and night... but they sound pretty damn good!

[St_Luke]

How many pairs of headphones do you have....?

:blink:

That mesh looks sweet.

I did have 6 sold 3 and brought 2 more   new ones arrive in a few days i hope ..... another stand on the   way

[L J T]

I just ordered some Dayton T250P Compression drivers from LSK to experiment with

Going to incorporate them in my next speaker build with pro woofers. A 2 way.

Any suggestions for 10" pro drivers that will be bass limited to 80Hz ?? Looking for a frequency response up to around 2kHz for the bass driver.

I have two Crown XLS 1500 Drivecores to power each driver.

Celestion CF1020 looks a good performer.

[hochopeper]

I just ordered some Dayton T250P Compression drivers from LSK to experiment with

Going to incorporate them in my next speaker build with pro woofers. A 2 way.

Any suggestions for 10" pro drivers that will be bass limited to 80Hz ?? Looking for a frequency response up to around 2kHz for the bass driver.

I have two Crown XLS 1500 Drivecores to power each driver.

Celestion CF1020 looks a good performer.

I dont have much experience with 10in drivers but just wondering what waveguide/horn you're going to use?

[L J T]

Probably the larger round Dayton guide or the 90x90 H110. Happy to experiment with both.

[Music..Man! :)]

Looks like St_Luke got his HD650's

[davewantsmoore]

I have two Crown XLS 1500 Drivecores to power each driver.

 

Unless your trying to run a rock concert then you may find yourself with poor gain structure  (ie.   sending a very small input signal to your amplifier, because you only need a few watts to get loud).

 

 

Going to incorporate them in my next speaker build with pro woofers. A 2 way.

Any suggestions for 10" pro drivers that will be bass limited to 80Hz ?? Looking for a frequency response up to around 2kHz for the bass driver.

 

Are you planning a passive crossover?    It can be quite a challenge, for this specific design.    Driver which have the high end extension, don't have the low end sensitivity.

 

Acoustic Elegance TD10M

B&C have a few suitable drivers

18Sound 10W500

Scanspeak discovery series if you're happy with something that has less sensitivity

[L J T]

Unless your trying to run a rock concert then you may find yourself with poor gain structure (ie. sending a very small input signal to your amplifier, because you only need a few watts to get loud).

Are you planning a passive crossover? It can be quite a challenge, for this specific design. Driver which have the high end extension, don't have the low end sensitivity.

Acoustic Elegance TD10M

B&C have a few suitable drivers

18Sound 10W500

Scanspeak discovery series if you're happy with something that has less sensitivity

Thanks for the suggestions Dave. I'll look into them.

No passive crossovers for this build.

I have an active 2 way stereo balanced crossover that will be used in conjunction with the Crown's internal crossovers, allowing me to create a band passed signal for the mid/bass driver. I am not focussed on low frequency response, output, or overall output. These are not my design goals. My intention is to build a bass limited 10" or even 12" with a compression driver that plays well down to 80Hz.

The external crossover and the Crown's both have LR24db/octave crossovers, so phase and output slopes will be very close.

The Crowns were chosen for their performance and features they provide in my current system. The preamp I am using allows the Crowns to be driven sufficiently and I understand your comments about gain structure.

Yes when the speakers are built they will only require a few watts at most to reach my preferred listening volume. It will be high efficiency, not necessarily high output. The high power is on hand for when I decide to change things in the future.

[davewantsmoore]

No passive crossovers for this build.

 

Makes it easier for you then, don't have to deal with the lumpy impedances, or the HP/LP filtering at 80hz   

 

 

I reckon there are probably more options out there for a 12" woofer .....  if you can handle going for a larger horn so you can cross at ~ 1khz

[L J T]

Makes it easier for you then, don't have to deal with the lumpy impedances, or the HP/LP filtering at 80hz

I reckon there are probably more options out there for a 12" woofer ..... if you can handle going for a larger horn so you can cross at ~ 1khz

You are correct Dave. I am modelling some 10"s and find they are limited by xmax and cone displacement. I have modelled the Celestion TF1230 and results look promising. I managed to model it within the needed passband and it's not limited by xmax or cone displacement. This should be promising as the program I am using only allows for a 12db/octave high pass signal to be applied to the predicted amplitude response, and of course it will be 24db/octave in reality.

Now I left my laptop at work, so no more sims until tomorrow

[davewantsmoore]

 I meant 12" drivers because there is more choice.   10s seem unpopular for some reason....  surprised to hear your're topping out a 10" if you are -6dB@80hz with a decent slope .....  but that all depends on how loud you are simulating for?!    

 

If the TF1230 meets your requirements, then plenty of 10s will work, surely?!.....  

[betocool]

Finished my headphone amp! Stage 3 completed!

 

The filed container with a transparent packing tape wallpapered on all sides:

 

The PCB with double sided tape on the bottom side:

 

Switch, jacks and LED mounted, as well as all innards:

 

The End:

 

Now... on to further projects...

[mwhouston]

@betocool; clean, neat build. Good work.

[Guest]

Very cool!

A red LED at the tip of the cigar would have been sweet though

[L J T]

I meant 12" drivers because there is more choice. 10s seem unpopular for some reason.... surprised to hear your're topping out a 10" if you are -6dB@80hz with a decent slope ..... but that all depends on how loud you are simulating for?!

If the TF1230 meets your requirements, then plenty of 10s will work, surely?!.....

Sorry Dave, I missed your post.

Yes a 10" it will be.

I have been doing a lot of simulations and the TF 1020 fits the bill nicely

It models well in the enclosures I have been playing with.

Now to get some MDF and make up a trial box.

[mwhouston]

Just completed another, yes another, Class D amp (4 in a row amd one to go). I use the mifi Eatern Audio Technologies, T4, 180W Tripath module. 500VA tranni amd single 15,000uf smother cap. PS can deliver 16A at 48V.

Amp sounds good so far. I'll start thread and post some images.

[thesavage]

 I'll start thread and post some images.

 Please post a link to your new thread in here. Always nice to see a detailed build!

 

Cheers,

 

Tim

[mwhouston]

Take  look at Class D power amp #4; http://www.stereo.net.au/forums/index.php?/topic/81219-my-4th-class-d-power-amp-with-the-t4-audiophile-module/?p=1331984