Recommended component upgrades

[wink]

Hey Bottleheads,
I'm starting on my journey down the DIY path. I ordered a few kits and they should arrive in the next day or two, one of them being the S.E.X. I scooped up the BH upgrades (c4s and impedance switch). The metal is going in for powdercoat this weekend and I'll probably start building the following weekend. I was wondering if I can get some recommendations on some upgraded components (aside from tubes) and some reliable vendors to purchase said parts from. I see a lot of cap, resistor, and pot's upgrades, I'm just not experienced enough down to component level to put together a great parts list with model/value #s. I'm not on a tight budget so I'm willing to pay for a good upgrade.
I'm mainly a headphone type of guy but I'm going to be looking to scoop up some bookshelf/desktop speakers to go along with my system. On the SEX page it recommends a speaker sensitivity of 97db. I've read about Blumenstein and they are definitely an option. Can anyone suggest any other highly sensitive speakers? Unfortunately for me a lot of them a freakin huge! I'm trying to stay away from DIY speakers for now unless its a kit that doesn't require me doing any cutting or milling (Lack of wood working tools and experience). My budget for the speakers is around $600 USD not including tax and shipping.
I appreciate the help, thanks for reading.

 

[Paul Birkeland]

Hello Wink,

We would strongly recommend using the stock parts for all of your kits for a variety of well thought out reasons.

In the SEX amp, the impedance switch kit will be the most useful upgrade for operating headphones, followed by the C4S upgrade.

Beyond that, most parts substitutions produce minor character changes in the amplifier.

-PB

 

[wink]

Hey Paul, thanks for the reply.
I thought the sex was all about experimenting? I have no intentions to turn it into a monoblock or a SEPP amp but wouldn't mind having the upgraded components. I understand that you all designed the amp a certain way for a reason, as a tech myself, there's always a little room for improvement. I only ask because I've seen a lot of crazy builds on here over time, I figured that some have improved on the design a bit. I did grab the available BH upgrades (c4s and switches). I guess I'll rock it stock while doing more research.
Thanks again!

 

[Paul Birkeland]

I figured that some have improved on the design a bit.

Yeah, cap rolling isn't actually changing the design, but rather just swapping parts. 

The amp is much easier to debug built stock, but after that feel free to go nuts on parts swapping.

 

[wink]

That's all I really wanted to do. Just a little component upgrade, not change the amp topology. I figured BH picks quality parts but also has to keep the overall price of the amp in mind when choosing the parts for the kit. I wasn't sure if parts with tighter tolerances, film over electrolytic caps, 60 year old hand wound resistors by voodo witch doctors from Albania, would add anything aditional to the overall performance of the unit. I'm definitely going to build the kits stock first, for initial troubleshooting like you mentioned, then upgrade after everything checks out. I apologize if my enthusiasm was taken the wrong way

 

[Paul Birkeland]

Oh, no worries, I was more implying that the expectation of change when rolling capacitor should be pretty tempered. 

There are even some times where I've spent big bucks on coupling caps, only to find that I liked something a lot less expensive a lot more. 

In the SEX amp, parts tolerance for caps and resistors is relatively unimportant for the most part (not true in the C4S upgrade, however).  A lot of folks change out the 0.1uF caps for something fancier.  Finding 1.5-3.3uF 630V upgrade caps can be difficult, and they tend to get large enough that they don't fit all that well.

Swapping out the volume pot is also popular. 

-PB

 

[Doc B]

One of the main reasons we encourage building the kit stock is that it makes it much more possible for us to help if any troubleshooting assistance is needed. It gets very difficult to sort out what might have happened if the amp has a different attenuator and so on when we have to work through the medium of forum posts to sort it rather than having the amp sitting on our bench. It's really pretty easy to swap out most of that stuff after the build as we keep the most popular components to be swapped in mind when we lay the chassis out.

 

[wink]

Hey Doc!

I totally understand. Thats what I had intended, it just didn't come out that way when I wrote the post.
Service would be a disaster if everyone was changing parts during the initial build. I just wanted to get a head start on ordering some suggested parts while everything else was getting  done.

 

[Paul Joppa]

I would suggest starting with the 0.1uF/600+v interstage coupling capacitor. Being small, it is less expensive to play with You may want to try a few different types - oil, plastic, mica, etc. Don't hesitate to lok at inexpensive non-audiophile-approved caps, such as mylar (polyester) - you will at least learn why they are not popular.

Second set of experiments - different values of parafeed capacitor. Stock is 1.5uF/600+v, but the range of 0.8uF to 2.7uF is worth exploring if you have speakers. There is some interaction in the deep bass between speakers and parafeed capacitor value; it may or may not be present with your speakers. I'd do this first with Solens, same as stock, just to find the value that gives you the most satisfying bass. Once you know that value, then in makes sense to try a different type. For some unknown reason, the most satisfying parafeed caps are often different from the most satisfying interstage caps.

Don't forget, most caps will take at least 50 hours of actual music before they are broken in enough to judge them - they almost all sound thin and nasty at first. Some types, like teflon, take ten times as long. It's a long, slow process!

 

[mcandmar]

I had very good results replacing the caps in mine, but as above build it stock first and make sure everything is working properly before making any changes.

As for type/brands of caps, there are plenty of "roundups" on the internet to read through, parse the data, add a pinch of salt, and you should hopefully come up with a short list.  The high voltage rating required does tend to limit your choices somewhat.  And to echo the above, i have found the more expensive boutique caps dont necessarily sound better.  If anything i have grown to really like the Solens, and for the price they are a bargain.  The .1uf interstage caps are certainly the place to start experimenting.

Build photos are mandatory!

Don't hesitate to lok at inexpensive non-audiophile-approved caps, such as mylar (polyester) - you will at least learn why they are not popular.

lol

 

[wink]

Thanks Paul and Mcandmar.
I've got a bunch of posts bookmarked on builds but most are just initial impressions. Very few have long term reviews on their devices. They do the build, add new parts, give initial impression, than you don't hear anything about it after. That's why I ask here. It was more direct and quicker to cut thru the BS.
My kits arrived today. WoopWoop! The metal is going out to powder coat tomorrow! I kinda feel guilty because the top panel is beautiful with the brushed design. Hopefully start building next weekend. Is it safe to Powdercoat the irons and transformer parts?
Gotta start shopping for speakers soon

Thanks again for all of the tips.