Matt, I'm with Rabbitz, I'll hang on until you are happy with the results and another confirmed addict.
Cases are not cheap to buy but very easy to find, there are always old cheap DVD players and broken amplifiers on the nature strips here when people move out of houses and can't throw everything in the rubbish bin.
Our local council has a recycle centre that sorts thru the rubbish as it is taken to the transfer station, I once bought a brand new down sleeping bag for $20-
Start scrounging
Cases are not cheap to buy but very easy to find, there are always old cheap DVD players and broken amplifiers on the nature strips here when people move out of houses and can't throw everything in the rubbish bin.
Our local council has a recycle centre that sorts thru the rubbish as it is taken to the transfer station, I once bought a brand new down sleeping bag for $20-
Start scrounging
The case is on its way soon, things have been hectic here looking for work.
Matt, don't buy amplifiers off eBay unless you know explicitly and specifically what it is you are buying, I would say that of the last 5 amps I bought: in the last few years, only one was advertised truthfully.
Working does not mean working well, but occasionally a bargain can be found.
Don't buy, scrounge, you are only after the cases and transformers to build chip amps after all.
Matt, don't buy amplifiers off eBay unless you know explicitly and specifically what it is you are buying, I would say that of the last 5 amps I bought: in the last few years, only one was advertised truthfully.
Working does not mean working well, but occasionally a bargain can be found.
Don't buy, scrounge, you are only after the cases and transformers to build chip amps after all.
Ok yeah, I was mainly thinking about using the cheap amps for cases and salvaging any parts.
Ok, thanks so much and good luck on the job hunt.
This economic state is effecting my family as well unfortunately, so I fully understand any waiting that is needed on my end.
Now I have a question for you guys, it has nothing to do with the speakers but I figure this is the easiest place to ask.
What does a buffer do? (Such as this one )
And more specifically what does it do in a preamp?
I bought mine from Allans music , the best source recently was DJ city in Melbourne
http://www.djcity.com.au/products/c...ro-2-way-stereo-3-way-mono-crossover_342.html
Although you will see the price is now $199-, but there is no difference in sound quality between Brand new in box and display or scratched and dented stock.
http://www.djcity.com.au/products/c...ro-2-way-stereo-3-way-mono-crossover_342.html
Although you will see the price is now $199-, but there is no difference in sound quality between Brand new in box and display or scratched and dented stock.
A buffer provides no gain but it will, if the upstream component or stage does not have a very low output impedance, reduce the output impedance. This increases the current driving capability of the system.mattcalf said:
Putting aside subjective claims, a buffer does neither good nor harm if the upstream stage already has sufficiently low output impedance to drive the next component or stage in the audio chain. It is therefore not necessary unless your components are not well matched, i.e. not capable of driving the next component in the chain. This is not usually a problem but can arise with valve preamps and with SS or valve headphone amps.
Ok tnargs thanks for your answer, it's alot clearer now.
My plan is to build a pre-amp with a bbp remote controlled volume control and I figure I'll build either a Pedja Rogic or a Pass B1 buffer to go with it.
I feel bad for starting this discussion in this thread, should I make a separate thread or is everyone cool with it?
My plan is to build a pre-amp with a bbp remote controlled volume control and I figure I'll build either a Pedja Rogic or a Pass B1 buffer to go with it.
I feel bad for starting this discussion in this thread, should I make a separate thread or is everyone cool with it?
The B1 buffer is very good indeed and extremely transparent.
Just does what it's supposed to by sorting out the impedance issues between the source > pot > power amp. I've found every power amp I've built did benefit from a buffer or an active stage as the pot alone caused roll offs and loss of dynamics.... that's even with following the 100:1 rules and a source with Zout <50R. The only amp that I've built that works well with a pot alone is a LM3875.
I built the no cap version (Zout 330R) by Salas and is about as simple as it gets. The power supply was a modified Jaycar / Altronics (Silcon Chip) and the pot remote controlled via an Altronics (Silicon Chip) kit. I mention those to give you an idea of where to source some of this stuff.
http://www.diyaudio.com/forums/showthread.php?postid=1654522#post1654522
I recently did one for a friend in Melbourne for use with a PrimaLuna valve power amp while he was waiting for a valve pre to be completed. He was using a DACT attenuator and noticed the benefit of the B1. A much smaller board and layout.... virtually point to point.
It's a sensible idea to ask your questions in this thread as it's a bit of the learning one at that and we have some idea of your goals. When you start getting your hands dirty with the electronics then go over to the relevant forum.
Just does what it's supposed to by sorting out the impedance issues between the source > pot > power amp. I've found every power amp I've built did benefit from a buffer or an active stage as the pot alone caused roll offs and loss of dynamics.... that's even with following the 100:1 rules and a source with Zout <50R. The only amp that I've built that works well with a pot alone is a LM3875.
I built the no cap version (Zout 330R) by Salas and is about as simple as it gets. The power supply was a modified Jaycar / Altronics (Silcon Chip) and the pot remote controlled via an Altronics (Silicon Chip) kit. I mention those to give you an idea of where to source some of this stuff.
http://www.diyaudio.com/forums/showthread.php?postid=1654522#post1654522
I recently did one for a friend in Melbourne for use with a PrimaLuna valve power amp while he was waiting for a valve pre to be completed. He was using a DACT attenuator and noticed the benefit of the B1. A much smaller board and layout.... virtually point to point.
It's a sensible idea to ask your questions in this thread as it's a bit of the learning one at that and we have some idea of your goals. When you start getting your hands dirty with the electronics then go over to the relevant forum.
Attachments
I've come up with a basic list of things I think my Pre-Amp will need:
2x B1 Buffers (for total 4 inputs 2 outputs)
1x 18v-0-18v toroidal transformer + 5v for volume controller
2x 18v regulators
1x 5v regulator
8x rca plugs (3 in/1 out)
2x XLR/jack combo (1 in/1 out)
1x remote volume control
I'm really hope for 2 outputs at least but I'm not sure if the bbp board will supply them. If not can two buffer board or a modifier buffer board give me an extra output?
With the regualators will they reduce voltage from my transformers, so if I can get an 18v trannie and a 9v trannie will the regulator correct the 9v to 5v(which is what I'm guessing the volume control will need)?
2x B1 Buffers (for total 4 inputs 2 outputs)
1x 18v-0-18v toroidal transformer + 5v for volume controller
2x 18v regulators
1x 5v regulator
8x rca plugs (3 in/1 out)
2x XLR/jack combo (1 in/1 out)
1x remote volume control
I'm really hope for 2 outputs at least but I'm not sure if the bbp board will supply them. If not can two buffer board or a modifier buffer board give me an extra output?
With the regualators will they reduce voltage from my transformers, so if I can get an 18v trannie and a 9v trannie will the regulator correct the 9v to 5v(which is what I'm guessing the volume control will need)?
Oh how I wish I was!! But...
- I'm too young
- I can't afford it
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I was planning ahead for something like the Behringer Electronic Crossover which takes XLR. But incase I don't end up buying one then i'll have the option of the 1/4" jack which can either go to a single ended amp or split into RCA with a custom cable.
Planning ahead is a good idea, but the Behringers are mono/stereo so you do need 2 out L & R to run as stereo splitters.
I use them with RCA to XLR cables I make up myself.
A couple of my amps run 1/4 inch inputs, the Alesis for instance but I thought most pro-amps these days used XLRs, if you do use XLR just remember that they are always crossover cables Male and Female
And the days of buying vinyl albums at Op-shops for 50 cents has well and truly gone, I kept all of mine and always look for them at garage sales.
I use them with RCA to XLR cables I make up myself.
A couple of my amps run 1/4 inch inputs, the Alesis for instance but I thought most pro-amps these days used XLRs, if you do use XLR just remember that they are always crossover cables Male and Female
And the days of buying vinyl albums at Op-shops for 50 cents has well and truly gone, I kept all of mine and always look for them at garage sales.
So the input that says 'not used' on the back, is actually used?
Back panel
I've accepted defeat on the 'multiple output' front, atleast in the pre-amp equation. Is there another device I can buy/build that will split my outputs into many without losing quality?
EDIT With the regualators will they reduce voltage from my transformers, so if I can get a 9v trannie will the regulator correct the 9v to 5v(which is what I'm guessing the volume control will need)?
Probably better off keeping it simple to start with and just use RCA.
Forget about the regs etc.... just get this kit as has all you need including 5V output for remote etc.
http://www.altronics.com.au/index.asp?area=item&id=K5501
It just needs the 1K1 resistors changed to 680R (mine used 5k trimpots for fine tuning) to give 9.75VDC. You only need 1 transformer with this a 15-0-15 or better and safer a 16VAC plug pack. It's connected to the lower 2 inputs of the power supply which is the junction of D1, D2 on the +ve rail side plus ground. The other AC connection on the -ve rail side is not used.
For the remote look no further than this. The pot is rubbish but the circuit is good.
http://www.altronics.com.au/index.asp?area=item&id=K5026
As far as inputs go just use a 4 way break before make 2 pole switch and for 2 outputs just use 2 RCA sets wired together as it will give 2 pre outs.
Forget about the regs etc.... just get this kit as has all you need including 5V output for remote etc.
http://www.altronics.com.au/index.asp?area=item&id=K5501
It just needs the 1K1 resistors changed to 680R (mine used 5k trimpots for fine tuning) to give 9.75VDC. You only need 1 transformer with this a 15-0-15 or better and safer a 16VAC plug pack. It's connected to the lower 2 inputs of the power supply which is the junction of D1, D2 on the +ve rail side plus ground. The other AC connection on the -ve rail side is not used.
For the remote look no further than this. The pot is rubbish but the circuit is good.
http://www.altronics.com.au/index.asp?area=item&id=K5026
As far as inputs go just use a 4 way break before make 2 pole switch and for 2 outputs just use 2 RCA sets wired together as it will give 2 pre outs.
Hi Matt, the splitter (XO ) has two sets of lettering; one on top one on bottom.
Bottom set is for stereo use, 2 inputs L & R, 4 outputs
( L low: L high / R low: R high )
and the XO can be used also with the Low outputs summed as a mono subwoofer
If used as a 3-way XO then you use a single input per unit and it works as a 3-way XO, but the pre-amp still has to work as stereo, and you then buy 2 units
if using a 3-way splitter I prefer the next model up as it is cheaper than two CX 2310.
If you price good quality passive cross-overs for low frequencies you realise that high value quality coils and capacitors can cost hundreds of dollars and are not as versatile as any reasonable active unit.
Our ears are not as sensitive to distortion in the lower frequencies and while some people do think that 4th order crossovers are too steep midrange drivers crossed over very low
( say 120/150 Hertz )
do seem to need steep slopes to perform at their best.
This is also to a degree dependent on how loud you play your music and I do crank it up quite often, especially for parties / although parties have their own needs and I have a separate system for parties ( louder but less defined ) but that is a different story and deserves a separate thread
Bottom set is for stereo use, 2 inputs L & R, 4 outputs
( L low: L high / R low: R high )
and the XO can be used also with the Low outputs summed as a mono subwoofer
If used as a 3-way XO then you use a single input per unit and it works as a 3-way XO, but the pre-amp still has to work as stereo, and you then buy 2 units
if using a 3-way splitter I prefer the next model up as it is cheaper than two CX 2310.
If you price good quality passive cross-overs for low frequencies you realise that high value quality coils and capacitors can cost hundreds of dollars and are not as versatile as any reasonable active unit.
Our ears are not as sensitive to distortion in the lower frequencies and while some people do think that 4th order crossovers are too steep midrange drivers crossed over very low
( say 120/150 Hertz )
do seem to need steep slopes to perform at their best.
This is also to a degree dependent on how loud you play your music and I do crank it up quite often, especially for parties / although parties have their own needs and I have a separate system for parties ( louder but less defined ) but that is a different story and deserves a separate thread
That is a good deal, has good options such as time delay on the woofers.
It is a good starting point, looks like you want to hit the ground running where sub-woofers are concerned.
If you want to jump right into using Bi-amping and run subs or big woofers with these bookshelves then think about doing the sealed box, you then play with XO frequency around the boxes natural roll-off of around 80Hz
Regards
Ted
It is a good starting point, looks like you want to hit the ground running where sub-woofers are concerned.
If you want to jump right into using Bi-amping and run subs or big woofers with these bookshelves then think about doing the sealed box, you then play with XO frequency around the boxes natural roll-off of around 80Hz
Regards
Ted
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