Hi Rupert
The link probably needs the little Rover thing, so here is a copy and paste
Hmm the link is not working too well try via Google looking up stereo coffee LDR
Best to send me a PM so we can work out your exact requirements like cabling.
Single input is OK, we will use a dual Bourns 250k Pot, One side doing cold and the other Hot. this is very similar to two of our single kits so pricing will reflect that.
Cheers / Chris
The link probably needs the little Rover thing, so here is a copy and paste
Hmm the link is not working too well try via Google looking up stereo coffee LDR
Best to send me a PM so we can work out your exact requirements like cabling.
Single input is OK, we will use a dual Bourns 250k Pot, One side doing cold and the other Hot. this is very similar to two of our single kits so pricing will reflect that.
Cheers / Chris
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Hi Paul
Thats great, our Type c board has a few added improvements, so will get one to you very soon. Yes we can do 2 inputs and two outputs. do you need each to be volume adjusted independently or both together ?. to do this we will change position of what is normally input 3 to be a second shunt. it will need 2 control boards.
Hear from you soon
Cheers / Chris
Thats great, our Type c board has a few added improvements, so will get one to you very soon. Yes we can do 2 inputs and two outputs. do you need each to be volume adjusted independently or both together ?. to do this we will change position of what is normally input 3 to be a second shunt. it will need 2 control boards.
Hear from you soon
Cheers / Chris
Ah, I see. Wouldn't it be possible to make it with a single pot fully balanced ? Sorry for my ignorance
ps. this link only works when copied into the address line of your browser
stores.ebay.com.au/stereo-coffee
Hi Chris
Just checking other applications for this beyond a passive pre-amp. Could it be used in an existing active pre-amp to replace input selector and volume control? I have a couple of pre-amps that use different resistance pots, 110K and 250K log, one tube based and one transistor.
Kind regards
Grant
Just checking other applications for this beyond a passive pre-amp. Could it be used in an existing active pre-amp to replace input selector and volume control? I have a couple of pre-amps that use different resistance pots, 110K and 250K log, one tube based and one transistor.
Kind regards
Grant
Ah, I see. Wouldn't it be possible to make it with a single pot fully balanced ? Sorry for my ignorance
ps. this link only works when copied into the address line of your browser
stores.ebay.com.au/stereo-coffee
Hi Rupert
Is the issue reliable tracking of each wiper ? If so i can see why a single appeals. I can do some tests to see if a single pot can be used with our circuitry balanced. Will report back
Cheers / Chris
Hi Paul
We did some tests with two power amps both 220k input impedance and and two sets of speakers ie parallel the existing output for dual output. It is quite successful.
Cheers / Chris
Hi Thanks for the feedback... Not sure what you mean
(my ignorance) .. I imagine a box with a single volume knob, not two .. but maybe I misunderstood something. Sorry.Hi Grant
Yes could be adapted to active pre amps removing switching and volume control problems they usually have. as it it is a L pad - it could feed other circuitry as a very clean first stage, If you are very familiar with one brand of preamp circuitry, adaption would be possible. Care would need to be taken to not lessen audio performance, which opens up chapters of how to use subsequent gain stages without distortion or coloration.
Phono stages would need initial gain and RIAA eq.
Cheers / Chris
Hi Thanks for the feedback... Not sure what you mean
Yes would be a box with a single knob, just a dual gang pot would make Double L Pad balanced much easier.
Cheers / Chris
Hi
We have made change to Type c boards ( all ) so as it is not necessary to add resistance at the LDR board end. the latest Type c board sound absolutely correct in terms of audio ( ie the best we have heard ), and we are very pleased to be finally shipping them. Staggering bass performance only when there is such sound on the CD, absolutely correct in terms of stereo balance, depth etc
We can presently build about 4-6 a day. ( ... er Oscar our dog has to have a walk or three ! )
There may be advantage in very small resistance from the Green block to each series and shunt anode, 8-10 ohms, but very minor.
Cheers / chris
We have made change to Type c boards ( all ) so as it is not necessary to add resistance at the LDR board end. the latest Type c board sound absolutely correct in terms of audio ( ie the best we have heard ), and we are very pleased to be finally shipping them. Staggering bass performance only when there is such sound on the CD, absolutely correct in terms of stereo balance, depth etc
We can presently build about 4-6 a day. ( ... er Oscar our dog has to have a walk or three !
) There may be advantage in very small resistance from the Green block to each series and shunt anode, 8-10 ohms, but very minor.
Cheers / chris
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Hi
Sources and how good they are - are extremely important to get the best from your stereo coffee ldr. We had been trialling our final revisions of type C on a Pioneer PDS507 with LM4562 op amps. We had reached the end of what the CD player could do, there was no more it could provide as a source.
Our many users are likely already using very good equipment as source, but its an area to really achieve the best from your equipment when using the stereo coffee ldr preamp.
Our experience was that we connected back in our old favorite the yamaha CDR HD1500 with all of its audio tracks recorded via a Type 1 DBX ... and WOW this confirms how good Type C is.
So our strong advice remains to use very good source components. If you want to take the path that we think is best, you will need to track down a DBX 150x compander or 155, and if can afford to do so partner it with a Yamaha hard disk recorder like the CDR HD1500 or CDR HD1300.
However if thats not in your budget, you can use the 150x real time, and follow the advices published in the DBX manual regarding mono and stereo phone plugs, as the 150x can be used balanced, and there is correct, and incorrect wiring when using them unbalanced.
Regarding our balanced stereo coffee kit, are XLR's needed by those looking at purchasing ?, or is it better we supply boards with facility for you to wire them ? We would supply instructions as to which board is Hot, and which board is Cold and conform with XLR standard accepted wiring.
Cheers / Chris
Sources and how good they are - are extremely important to get the best from your stereo coffee ldr. We had been trialling our final revisions of type C on a Pioneer PDS507 with LM4562 op amps. We had reached the end of what the CD player could do, there was no more it could provide as a source.
Our many users are likely already using very good equipment as source, but its an area to really achieve the best from your equipment when using the stereo coffee ldr preamp.
Our experience was that we connected back in our old favorite the yamaha CDR HD1500 with all of its audio tracks recorded via a Type 1 DBX ... and WOW this confirms how good Type C is.
So our strong advice remains to use very good source components. If you want to take the path that we think is best, you will need to track down a DBX 150x compander or 155, and if can afford to do so partner it with a Yamaha hard disk recorder like the CDR HD1500 or CDR HD1300.
However if thats not in your budget, you can use the 150x real time, and follow the advices published in the DBX manual regarding mono and stereo phone plugs, as the 150x can be used balanced, and there is correct, and incorrect wiring when using them unbalanced.
Regarding our balanced stereo coffee kit, are XLR's needed by those looking at purchasing ?, or is it better we supply boards with facility for you to wire them ? We would supply instructions as to which board is Hot, and which board is Cold and conform with XLR standard accepted wiring.
Cheers / Chris
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Attachments
Ask and you will receive
Works well thanks again Chris.
Hi Paul
Glad to help.
Cheers / Chris
I thought I'd chip in here and post some comments I've just made to Chris on the latest control board I've received from him.
"Have fitted the 4th control board (that I’ve received).
I’ve just had another listen and I’m
delighted with the sound.Straight away I could hear that the music was a lot
more relaxed and easier to listen to.
The sound verges on edgy but doesn’t get
there! Am finding that record noise (pops and clicks) on noisy records is still
noticeable.Doesn’t affect CD’s of course.
It’s very detailed. I’m hearing more in the music now.Bass is more
defined as well.
Maybe you can improve on it,but not sure how,unless it’s in the highs where
the pops are! Great on clean LP’s.I’ve always been very conscious of steely
treble.And I have a few bright LP’s that I’ve been fighting with for many
years,hoping one day to be able to listen to them without flinching!No
problems listening to them with this LDR.
For now I have no urge to put the Goldpoint back in,just loving the detail
and clean musical sound! Very unlike the boards before this one,where it was
very edgy,and I couldn’t listen for long! Wondered what I’d bought into!"
"Have fitted the 4th control board (that I’ve received).
I’ve just had another listen and I’m
delighted with the sound.Straight away I could hear that the music was a lot
more relaxed and easier to listen to.
The sound verges on edgy but doesn’t get
there! Am finding that record noise (pops and clicks) on noisy records is still
noticeable.Doesn’t affect CD’s of course.
It’s very detailed. I’m hearing more in the music now.Bass is more
defined as well.
Maybe you can improve on it,but not sure how,unless it’s in the highs where
the pops are! Great on clean LP’s.I’ve always been very conscious of steely
treble.And I have a few bright LP’s that I’ve been fighting with for many
years,hoping one day to be able to listen to them without flinching!No
problems listening to them with this LDR.
For now I have no urge to put the Goldpoint back in,just loving the detail
and clean musical sound! Very unlike the boards before this one,where it was
very edgy,and I couldn’t listen for long! Wondered what I’d bought into!"
Hi
What Neilsan said and we are experiencing is this latest preamp rev C2 revealing everything what is coming off your CD player or LP. - like never before. Following Neilsans reply we have changed the diode placement instead of v+ of opamp to now have its anode extending from the board output, which is better .
We have ordered in additional parts that will take about 2 weeks to arrive, For sales in the mean time we are locally obtaining these same parts so the current large backlog we have of supplying these latest amazing C2 boards does not grow further.
For those constructors who just cannot wait, add a 6.8uH axial inductor 1/2 watt between control board out and middle pin of pot... this will give you a small indication of where we are heading. This inductor is planned to be a parallel arranged across the two lines of output ie 2x 15uH providing about 7.5 uH
due to the chance of constructors getting orientation of the prior mentioned diode the wrong way around we will not recommend its placement, so please await a new board.
Marco will send you new boards as soon as we get these parts.
Cheers / Chris
What Neilsan said and we are experiencing is this latest preamp rev C2 revealing everything what is coming off your CD player or LP. - like never before. Following Neilsans reply we have changed the diode placement instead of v+ of opamp to now have its anode extending from the board output, which is better .
We have ordered in additional parts that will take about 2 weeks to arrive, For sales in the mean time we are locally obtaining these same parts so the current large backlog we have of supplying these latest amazing C2 boards does not grow further.
For those constructors who just cannot wait, add a 6.8uH axial inductor 1/2 watt between control board out and middle pin of pot... this will give you a small indication of where we are heading. This inductor is planned to be a parallel arranged across the two lines of output ie 2x 15uH providing about 7.5 uH
due to the chance of constructors getting orientation of the prior mentioned diode the wrong way around we will not recommend its placement, so please await a new board.
Marco will send you new boards as soon as we get these parts.
Cheers / Chris
Hi
Today we tried our stereo coffee ldr preamp with placed inductors and is very special. An interesting observation though worth noting for those on the forum using a quad 405 with our preamp.
Our 405 has The DC Daylight mod with non inverting opamp stage, and repositioned C8. We tried a AD847 opamp and asked ourselves why it sounds so good with the stereo coffee preamp. The reason that we discern is that the AD847 has ability with its voltage swing to overcome R12 and C6 that are placed to not upset the dumper stage with excessive high frequencies. It appears the normal selection of opamps used with the 405 just cannot drive R12 and C6, or more likely other preamps are just so lacking in dynamics you won't hear it anyway.
End result AD847 equipped Quad 405 with DC Daylight mods to input stage and C8, partnered with our stereo coffee preamp is a very good combination. Have also tried a quad 909 and you would be hard pressed to find a better amp.
We will try other low distortion amps but current dumping amps and our stereo coffee preamp are a great and recommended combination.
Cheers / Chris
Today we tried our stereo coffee ldr preamp with placed inductors and is very special. An interesting observation though worth noting for those on the forum using a quad 405 with our preamp.
Our 405 has The DC Daylight mod with non inverting opamp stage, and repositioned C8. We tried a AD847 opamp and asked ourselves why it sounds so good with the stereo coffee preamp. The reason that we discern is that the AD847 has ability with its voltage swing to overcome R12 and C6 that are placed to not upset the dumper stage with excessive high frequencies. It appears the normal selection of opamps used with the 405 just cannot drive R12 and C6, or more likely other preamps are just so lacking in dynamics you won't hear it anyway.
End result AD847 equipped Quad 405 with DC Daylight mods to input stage and C8, partnered with our stereo coffee preamp is a very good combination. Have also tried a quad 909 and you would be hard pressed to find a better amp.
We will try other low distortion amps but current dumping amps and our stereo coffee preamp are a great and recommended combination.
Cheers / Chris