Surface Mounted Devices

[Msegal]

Hi. I have heard that McIntosh has switched its most recent preamplifier line to the use of SMD's rather than standard circuit boards.
I am not sure I understand the technology and how it relates to sound quality. I would say the most recent line of preamplifiers (C1100,2600,52 and 47) are their quietest and possibly best sounding preamplifiers to date.

Is anyone here able to provide information relating to the use of SMD's, production efficiency and sound quality?
Thanks.

Best regards,

Mike S.

[rjryan]

Hi, Michael,

Speaking in general terms:

Sound quality is hard to quantify for SMD, except for the consistency factor. Basically, the components are soldered directly to the circuit board without the extra wire, or holes in the board that are required for someone to solder it manually. The production is more efficient, since there are machines cranking out the product, and in some cases, more accurate. I say "in some cases", because I believe that there are some folks that are truly gifted in point to point wiring and component matching that can far surpass a machine...but it'll cost ya, and rightfully so! My speculation - upper level McIntosh gear had their top artisans doing the boards....much like the person that winds all the transformers for the amps. Given the performance and the price drop on the new pre-amps, I think I'm good with the new procedure :-)

[W9TR]

SMD is just a mounting description. It doesn't say what's inside the device or how it was made. Ultimately that's what really matters in the end.
There are are really good SMD parts, along with some really bad sounding ones. It's up to the designer to choose the correct part for the application.
SMD is much more efficient from a manufacturing standpoint. The leads of through hole parts must be formed on special machines and then sequenced for placement on a different set of machines. This takes 10x more time than SMD parts, which are supplied on reels or cartridges for direct placement on the printed wiring board.

Many audiophiles feel point to point wiring "sounds better" than using pwb's. The same thinking is often applied to through hole vs. SMT manufacturing techniques.

In the end it is up to the designer to choose the right parts for the application.

McIntosh uses both through hole and SMD techniques, allowing the engineers to choose the correct parts for the job.

Regards,

Tom

P.S. I have spent my career developing high volume electronics products using both through hole and SMT technologies.

[rjryan]

Originally Posted by W9TR

SMD is just a mounting description. It doesn't say what's inside the device or how it was made. Ultimately that's what really matters in the end.
There are are really good SMD parts, along with some really bad sounding ones. It's up to the designer to choose the correct part for the application.
SMD is much more efficient from a manufacturing standpoint. The leads of through hole parts must be formed on special machines and then sequenced for placement on a different set of machines. This takes 10x more time than SMD parts, which are supplied on reels or cartridges for direct placement on the printed wiring board.

Many audiophiles feel point to point wiring "sounds better" than using pwb's. The same thinking is often applied to through hole vs. SMT manufacturing techniques.

In the end it is up to the designer to choose the right parts for the application.

McIntosh uses both through hole and SMD techniques, allowing the engineers to choose the correct parts for the job.

Regards,

Tom

P.S. I have spent my career developing high volume electronics products using both through hole and SMT technologies.

Very informative, Tom! Thanks!

[Cohibaman]

I echo what Tom and Ryan said and I'll add one thing...SMD boards are more challenging to do board-level repair when a component goes bad. I've done some rework on a few pieces of equipment, one of which was a McIntosh MS300 music server. It takes a steady hand, good lighting, good eyesight, a special soldering station, and a lot of patience!

[Msegal]

Originally Posted by W9TR

SMD is just a mounting description. It doesn't say what's inside the device or how it was made. Ultimately that's what really matters in the end.
There are are really good SMD parts, along with some really bad sounding ones. It's up to the designer to choose the correct part for the application.
SMD is much more efficient from a manufacturing standpoint. The leads of through hole parts must be formed on special machines and then sequenced for placement on a different set of machines. This takes 10x more time than SMD parts, which are supplied on reels or cartridges for direct placement on the printed wiring board.

Many audiophiles feel point to point wiring "sounds better" than using pwb's. The same thinking is often applied to through hole vs. SMT manufacturing techniques.

In the end it is up to the designer to choose the right parts for the application.

McIntosh uses both through hole and SMD techniques, allowing the engineers to choose the correct parts for the job.

Regards,

Tom

P.S. I have spent my career developing high volume electronics products using both through hole and SMT technologies.

Thanks for your answer.
I thought it was more manufacturing related than sound quality.

[Msegal]

Originally Posted by rjryan

Hi, Michael,

Speaking in general terms:

Sound quality is hard to quantify for SMD, except for the consistency factor. Basically, the components are soldered directly to the circuit board without the extra wire, or holes in the board that are required for someone to solder it manually. The production is more efficient, since there are machines cranking out the product, and in some cases, more accurate. I say "in some cases", because I believe that there are some folks that are truly gifted in point to point wiring and component matching that can far surpass a machine...but it'll cost ya, and rightfully so! My speculation - upper level McIntosh gear had their top artisans doing the boards....much like the person that winds all the transformers for the amps. Given the performance and the price drop on the new pre-amps, I think I'm good with the new procedure :-)

That makes perfect sense. [emoji1360]

[tdelahanty]

Theoretically SMT should be more reliable because there are far fewer plated thru holes, especially with multi layer Bds. (usually up to 4 layers). We'll use a 14 pin IC for example, there may be many on the Bd, and all 14 legs (pins) must be fit in corresponding holes, very difficult and time consuming. If the Bd is multi layer tracks on each layer must be precisely located above or below the other layers and plated thru to make contact. With SMT only locations which access another layer are plated thru.

In our PWB shop single layer or two sided (top & bottom) Bds were produced at 98% pass rate. Very complex multi layer Bds may run as little as 50% pass rate. So mainly it comes down to reliability, cost and waist .

[W9TR]

Hi all..thanks for the positive comments on my post. I think its great that people are interested in how their gear is made.

One of the things I forgot to mention is that lots of through hole parts are disappearing. This represents a real challenge for boutique audio manufacturers because they will not be able to afford SMT equipment and will have to outsource that aspect of their production.

Hats off to McIntosh - they have made a significant investment in automated SMT and through hole manufacturing equipment so they can use the correct part for the task at hand, without having to go outside to third party vendors.

To further tdelahanty's comments, SMD is dramatically more reliable than other assembly technologies. A large consumer electronics manufacturer I know runs 2.25 billion smd component placements per year and has a 0.5 ppm failure rate in test. The through hole failure rate is 100x higher.

Tom

[tdelahanty]

I can remember seeing pictures, on this website, of Mac's factory and was surprised to see employees loading Bds by hand. We also did this many years ago. The initial cost of automation was very expensive but in the long run did pay for itself by reducing man-hours and defects. Solderability is also much better when using wave-solder automation for thru-hole or SMD's. In some cases it was almost cheaper to throw away defective PWB's than to t-shoot, repair and retest.