The ultimate CD-player!?

[pangea]

Hi all ...... I have been following this thread with interest and have since gone out and bought a SCPH-1002 from a local pawn broker. I have been using a Harmon/Kardon CD player for years it cost me about au$750 12 years or so ago and was at the time the best sound for the money. Anyway I tried the ps1 and was quite surprised on how good it sounded, I used the swing CD from Robbie Williams with lots of brass in it and to my amazement the brass sounded less harsh and cleaner than the H/K also with an apparent improvement in bottom end. I have the swing CD and the live DVD of the same tracks, on the credits of the DVD there is a studio version of a track which is on the CD, so therefore I have a DVD and CD version of the same track, I would stick my neck out an say that initially I was disappointed with the quality of the CD vs the DVD which is understandable given the difference in bit rates and sample rates but played through the ps1 the CD quality sounds just as good as the DVD track of the same. Now before the nit pickers hound me down in droves let me qualify my statements.... the terms "sound as good as" etc are based wholly on what you are comparing it against, some guys with top of the range CD players might say there is little or no appreciable difference where as other guys with less than top of the range gear might say the opposite. So rather than enter into an argument of who's ears are better and who's CD player is the best I am prepared to say that stacked up against my medioka H/K CD player and Sansui DVD player the ps1 sounds very very good indeed ... The fact that the output level is less than most other CD players … well not a problem I can add some gain into my Aphex 10/4’s ….. as far as screening/shielding the power supply I have found that "straight out of the box" is fine, the only time I did induce some noise into my system was when I had the video output connected to my “live chassis” TV. The ps1 will do me until I can find a super high quality "stand alone" D-A Converter (at the right price) and start using optical or coax inputs.



My system comprises of JBL 4435'2 bi-amped, 2 X BGW 250D's bridged driving the LF and a JBL MPX300 driving the HF via a JBL 5235 X over network and an Aphex 204 Aural Exciter and a couple of Aphex 10/4's and a set of 4430's awaiting amplifiers and now a PS1 !!!

Glad to hear you liked it and and to hear that your experience is similar to my own.

Now let me ask you something about your BGW 250D, if you don't mind.
Do your BGW's get very hot on the transformer and do the transformer create any humming noice (50/60Hz)?

I have one of those and the tech-shop says it's OK, but I'm not convinced.

Mine is getting to hot to touch on the transformer after a while, say an hour or so, even on idle. The transistors stay cool on my amp.

Your input here would be highly appreciated, thanks

BR
Roland

[Aussie Pete]

I forgot to mention Roland ...... thanks for the heads up on the ps1 it is appreciated ... down to the BGW 250D .... ok mine I built myself from the original schematics which I "borrowed' when working for a national commercial television broadcaster here as senior tech, the advantage of building it was that I adopted a "no compromise" approach with respect to passive components ... ie MKT series German capacitors and 1% metal film resistors and a ceramic substrate version of the input IC, I re-designed the pcb (back then using Bishop Tape) but basically the same layout as the original with the exception of the octal input socket arrangement, I imported a heatsink extrusion that was as close to the original as possible from Germany which took around 6 months to get here and then had 2 channels milled out of each heatsink to accommodate the output devices, I used 2 Torrodial transformers for the power supply (1 independent transformer, rectifier and filter caps for each channel) and copied some novel Bryston circuitry for LED Level indication using bi coloured LED’s, Clipping (measuring the voltage difference between the DC power supply rail and the peak voltage of the output signal) rather than the usual crude method, Power Supply Integrity and DC Offset, this I then had to design/interface into the existing output relay so in the event of a fault it would de-activated the output relay. I did this work back in 1987 and these amps have never let me down since ….. at the time I did have access to Bryston schematics and could have copied the 2B and/or 3B but Bryston and BGW did the same later on and they probably all do it now is they will have their own semiconductor number stamped on the device and in most cases they will be beta matched which are not available outside of Bryston BGW etc. Yes it is possible to substitute other generally available semiconductors but my humble opinion is that if you are going to copy something it needs to be at the very least equal to or better than the original and substituting semiconductors might make a sine wave at the output but there are a whole lot of other criteria that have to be considered and operating a device in it’s linear part of the beta curve it primary, substituting …. Well you may have to re-bias the devices to operate in the linear part of the curve and then in my opinion it becomes a completely different amplifier with completely different sonic attributes. Ooops of track again, so back to your question re: the transformers …. Some types of transformers can be inefficient and do run warm to hot …. Not an issue …. If it’s making a noise and given it’s age then it could be that the clamping arrangement around the laminations has become slightly loose or the windings have become loose because the laquor they were dipped in has broken down and become brittle over time or something … the important question is does the buzzing noise increase with load?? … my guess is that it’s probably nothing to worry about but there are some quiescent current checks that could be done just to make sure the electronics isn’t drawing more that it should at idle, I do have the original owners/schematic handbook if it is of any use to you.



If you are interested I have posted some pics of my built BGW’s.



I also stated that I have a JBL 5235 xover …. This as well is a direct copy of the original (sorry Mr. JBL) nothing at all outstanding in its design/topology … very basic but does the job and gets the eq right (close to but not standard 12db/octave Butterworth slopes)



I also copied the English Quad 405 “Current Dumping” Amplifier of the 70’s as well …..It was regarded as the top of the top back then, operating in class A at lower levels then to quasi comp at higher levels … but then you have a look at the cct and specs and find out they have slew rate limited the input to a couple of volts/microsecond … no wonder they only used 1 output devices per rail … there was no way that those little babies were ever going to be overworked…. Off track again … many apologies... let me know if I can be of any further help to you.

[Ian Mackenzie]

Nice diy amp.

Regards a reference I am hope for one of these in my Xmas stocking

http://www.apogeedigital.com/products/minidac.php

[pangea]

I forgot to mention Roland ...... thanks for the heads up on the ps1 it is appreciated ... down to the BGW 250D .... ok mine I built myself from the original schematics which I "borrowed' when working for a national commercial television broadcaster here as senior tech, the advantage of building it was that I adopted a "no compromise" approach with respect to passive components ... ie MKT series German capacitors and 1% metal film resistors and a ceramic substrate version of the input IC, I re-designed the pcb (back then using Bishop Tape) but basically the same layout as the original with the exception of the octal input socket arrangement, I imported a heatsink extrusion that was as close to the original as possible from Germany which took around 6 months to get here and then had 2 channels milled out of each heatsink to accommodate the output devices, I used 2 Torrodial transformers for the power supply (1 independent transformer, rectifier and filter caps for each channel) and copied some novel Bryston circuitry for LED Level indication using bi coloured LED’s, Clipping (measuring the voltage difference between the DC power supply rail and the peak voltage of the output signal) rather than the usual crude method, Power Supply Integrity and DC Offset, this I then had to design/interface into the existing output relay so in the event of a fault it would de-activated the output relay. I did this work back in 1987 and these amps have never let me down since ….. at the time I did have access to Bryston schematics and could have copied the 2B and/or 3B but Bryston and BGW did the same later on and they probably all do it now is they will have their own semiconductor number stamped on the device and in most cases they will be beta matched which are not available outside of Bryston BGW etc. Yes it is possible to substitute other generally available semiconductors but my humble opinion is that if you are going to copy something it needs to be at the very least equal to or better than the original and substituting semiconductors might make a sine wave at the output but there are a whole lot of other criteria that have to be considered and operating a device in it’s linear part of the beta curve it primary, substituting …. Well you may have to re-bias the devices to operate in the linear part of the curve and then in my opinion it becomes a completely different amplifier with completely different sonic attributes. Ooops of track again, so back to your question re: the transformers …. Some types of transformers can be inefficient and do run warm to hot …. Not an issue …. If it’s making a noise and given it’s age then it could be that the clamping arrangement around the laminations has become slightly loose or the windings have become loose because the laquor they were dipped in has broken down and become brittle over time or something … the important question is does the buzzing noise increase with load?? … my guess is that it’s probably nothing to worry about but there are some quiescent current checks that could be done just to make sure the electronics isn’t drawing more that it should at idle, I do have the original owners/schematic handbook if it is of any use to you.



If you are interested I have posted some pics of my built BGW’s.



I also stated that I have a JBL 5235 xover …. This as well is a direct copy of the original (sorry Mr. JBL) nothing at all outstanding in its design/topology … very basic but does the job and gets the eq right (close to but not standard 12db/octave Butterworth slopes)



I also copied the English Quad 405 “Current Dumping” Amplifier of the 70’s as well …..It was regarded as the top of the top back then, operating in class A at lower levels then to quasi comp at higher levels … but then you have a look at the cct and specs and find out they have slew rate limited the input to a couple of volts/microsecond … no wonder they only used 1 output devices per rail … there was no way that those little babies were ever going to be overworked…. Off track again … many apologies... let me know if I can be of any further help to you.

Thanks for all the info and pic's, very nice job there indeed!

I think you are right about the loos laminates in the transformer. It seems someone has added a piece of a copper sheet on top of the transformer and has poured some lacquer over the transformer, probably to improve the clamping and to try to silence the transformer. It looks a bit suspicious, so I think I will return it to the guy I got it from, instead.

He has said he'll take it back, no problem, so I think I will just play it safe here.

Thanks again.

BTW, is is there a connection between Bryston and BGW?

BR
Roland

PS: The amp did come with a manual, which included schematics and an individual test report, quite nice tho. DS.

[Aussie Pete]

Thanks for the compliments guys ….. an awful lot of time went into building/re-designing those amps and I was sort of hooked on BGW after copying their BGW 202 pre-amp first, if you ever get a chance to buy one of those do it (circa 1977) …. One of the best sounding RIAA pre-amps you will ever listen to. Most of the reviews canned it at the time but what they were listening to was for the first time ever from and RIAA pre-amp was transients, this was evident in BGW’s design topology, instead of the usual design topology of RC networks in the negative feedback chain (which knock the hell out of the transient response or transient rise time) to obtain the required slopes BGW used a novel approach of “long tailed pairs” and differential techniques to obtain the slopes and the sonic result was outstanding. There were not many of these about and certainly here in OZ the half dozen or so that came out here went into radio broadcasters, the pre-amp was never aimed at the domestic market, it was a professional piece of equipment and priced accordingly. You may be surprised at how many so called top end pre-amps or any piece of audio gear for that matter both in the domestic and even professional/broadcast use crappy designs and get away with it, put a nice front panel on it and some bright lights to stun the golden eared hi-fi nut then give it to the marketing experts to put some new spin on it and pay off the reviewers and hey presto ….. a popular pre-amp is born…. What a cynic!!



There is no connection between Bryston and BGW it’s just at the time we were using both at the studios, Bryston was fairly new to the scene then and I was leaning towards the BGW because of previous experience. Bryston generally speaking use the topology approach of many lower gain stages throughout the amp which is a far better approach with respect to stability and linearity but more expensive, rather than using less higher gain stage approach which is cheaper but then having to use large amounts of negative feedback to stabilise the thing. Bryston manufacture a very very fine amplifier both in cct topology and performance and if I had the spare money I would buy 2, in my view their design approach is one that I am a believer of.



Thanks for the link on the DAC Ian, it seems to be priced quiet reasonably even at US$$, do you know if they have an Australian distributor, it would be nice to be able to listen to it. Previously I was thinking of a Bryston pre-amp with the option of an internal DAC but again they are big bucks and after buying those 4435’s recently and now hanging on to my 4430's I somehow don’t think my marriage could stand another expensive acquisition like the Bryston ……. Well not yet anyway ….. I think I will let the dust settle for a while.

[morbo!]

some nice work pete

how much to build me one!

luv the donut shaped power thingy`s

[Aussie Pete]

some nice work pete

how much to build me one!

luv the donut shaped power thingy`s

Hows it going Morbo .... thanks again ... unfortunatley if I had to charge what it cost me in time those amps would cost around $5,000.00 each but next time I decide to rip off someone elses design I will post here first, get some orders and bring the price down ... hows that sound

[Zilch]

luv the donut shaped power thingy`s

[morbo!]

if i start saving now and you start building in 6 months we might have a deal!

[cruisaire]

Just picked up a local, working 7501 (a model I didn't already own) for 10 with tax and 2 controllers. My 1001 is still the "best of breed". I'm using it with the repackaged Sonic T amp. Fulll range 4-inchers are sweet and pretty damned loud to boot!

[pangea]

Just picked up a local, working 7501 (a model I didn't already own) for 10 with tax and 2 controllers. My 1001 is still the "best of breed". I'm using it with the repackaged Sonic T amp. Fulll range 4-inchers are sweet and pretty damned loud to boot!

If you can find a 5001 or a 5501, you might be able to use the laser-kit and power supply for spare parts.

The 7501 isn't the best sounding model, as you have already found out.

BR
Roland

[cruisaire]

Got a 5501 for $2.89 today. Looks like it was never played with! Passed on another 7501 at $10.

[pangea]

Got a 5501 for $2.89 today. Looks like it was never played with! Passed on another 7501 at $10.

A really good find! Congrats!!!

Now you''l be set up for many years of musical excitement.

BR
Roland

[Nightbrace]

What makes this Playstation soo much better than my CDPC701ES Sony? I think they do in fact sound identical, but neither sound nearly as good as my NAD. Again you never answered me, how do I know I am NOT hearing jitter??

[pangea]

What makes this Playstation soo much better than my CDPC701ES Sony? I think they do in fact sound identical, but neither sound nearly as good as my NAD. Again you never answered me, how do I know I am NOT hearing jitter??

I didn't go in to a lengthy explanation, since you had already made up your mind.

You said you prefer the NAD and that's fine with me. I would NEVER try to convince you otherwise, because I'm not selling the PS1, so I said "fine, go for the NAD".

I did try to explain the best I could, how "jitter" might be heard, but that does not mean that you can sense the difference between CD-jitter and a good Vinyl record, "n'est ce pas"!?

BR
Roland