Bottlehead Upgrades

[kgoss]

Hello Everyone,

This post is directed to the Bottlehead designers (Doc, PJ, and anyone else who designs Bottlehead equipment).  First of all I'd like to thank you for all the hard work you put in designing this equipment and on top of that helping people who post questions on this board.  Everything you produce is a quality product in stock form and every piece is worthy of upgrading, which is why I'm posting this suggestion.

My degree is in Computer Science, not Electrical Engineering.  I love music and love the kits, but I'm definitely a "solder by numbers" kind of builder.  Not someone who actually understands the circuits I'm putting together.  So when it comes to upgrading I have to rely on forum searches to see what parts make good upgrade candidates.  While that does work its not easy and plus when a post is talking about upgrading the "grid stopper resistor" I then have to figure out which resistor they are talking about.  Trying to figure out which electrolytic capacitor is the last one in the power supply and a candidate to bypass or which resistors are in the signal path using the schematic might be a piece of cake for some people, but it is not easy for me.

What I would like to see is a sticky post, maybe one in each product's category on the forum, with upgrade suggestions from the folks who designed the gear.  Not to say that upgrades posted on the forum by the community aren't great, they are.  But having more detailed information in an easy to find location would be better in my opinion.  I'm not asking you to recommend a manufacturer's part to use for any upgrade because I realize that is a matter of personal taste and opinion in a lot of cases.  Personally I would like to see suggested upgrade parts because you guys have heard a lot more stuff than I'll ever get the chance to.  But I understand if you would rather not head down that road.

I would like to see something like this (I'm making up the entries by the way):

S.E.X Amp
Part Description                    Part Value / Type               Terminal Numbers                  Bang for the buck  (1 low, 2, medium, 3 high)
Grid Stopper Resistor            500K 1/4W / Carbon          23, 25   -   43, 45                    2    (I know its subjective, but that is fine)
Coupling Capacitor               1.0uF 400V                        18, 21   -   48, 31                    2
Upgrade Volume Pot             100K                                  N/A                                       3

Different pieces of equipment would have different parts and different bang for the buck ratings for the same parts.  For example, upgrading the volume pot on the S.E.X amp might get a bang for the buck rating of 3 which is the highest.  And the same upgrade on a Foreplay III might get a bang for the buck rating of 1 (lowest) because the kit comes with the sweetest whispers attenuators which are stepped and accept through hole resistors.

Anyway, I know this would help me decide what to upgrade and in what order and I think it would help a lot of other people too.

Thanks for your consideration,
Ken

[4krow]

Ken, I exactly agree with you. I am mostly a parts changer myself, and easily fooled(speaking for myself). This site is better than most when it comes to explaining things(I feel like I am doing taxes for a large corporation when I try to 'research' on some sites). Having said that, I only hope that I haven't missed something important, posted years ago about an upgrade or something. On the other hand, when I looked for the stepped GoldPoint attenuator to replace the one used in the FP III, I quickly found it, posted by Deb K, complete with part numbers and photos! Perfect post Deb, thanks! It's one thing to talk about something, it's another to properly document your findings making it useful for all.

[Grainger49]

Ken,

The designers haven't weighted in, so, "what is a grid stopper, where is it?" is always an easy post and no one will make you feel bad about asking it. 

There are grid stoppers and plate stoppers depending on the piece of equipment.  Stopper resistors are attached directly to the tube socket pins because they have to have short leads.  They are always carbon composition resistors from Bottlehead.  That means they are the color of chocolate milk, maybe a little darker brown.  But, being brown and attached to the tube socket with one lead very, very short identifies them.  Your schematic has tube pin numbers on them and you should number the sockets when you build the kit.  So that also makes them easy to identify. 

Moving to another question, the last capacitor in the power supply is the one that feeds out to the tubes and is on the opposite end of the power supply from the diodes.  Your manual calls out the diodes so you can follow the assembly to find the "last capacitor."

Post in the appropriate folder and someone will tell you which resistors are in the signal path.

As "bang for the buck," a phrase I use often it is hard to compare a $6 capacitor with a $50 capacitor (coupling capacitors are easily identified with the great pictures in Bottlehead manuals) and $600 of transformer & choke upgrades.  Pretty much as you have indicated.  Much of that depends on your disposable income rather than someone else's judgement.

[earwaxxer]

I will have to chime in with Granger, with more of the same. There are no real right and wrongs here. Many variables to consider, one being cost. The other being the type and sound of the system you have, and what it is you are looking for - ex. more 'definition', more 'analog', bigger 'sound stage', all of the above etc. As part of the hobby I feel it is important to get to know your gear and what it does. With that comes experimentation. Dont take anyones word as gospel. Use other opinions as a guide. Do your homework and have fun! You might even short some things out here and there. Sparks and smoke add to the excitement (in small infrequent doses).

[Grainger49]

Eric has made me think of more.  With less expensive caps you get better 'definition', more 'analog', bigger 'sound stage' just as Eric says, but only one.  You might get an improvement on another but not all three.  For all three in spades you need to go to the higher priced spread, V-Cap Teflon, Audio Note, Duelund cast, Mundorf S/G/O, that kind of stuff.  There is a reason they are more expensive.

But if you know what is most important to you, you can ask for suggestions in more affordable caps and find something that makes you happy.

[kgoss]

Thanks for the replies guys, that's what makes this forum so great.  But the point of my original post wasn't a specific upgrade, but rather to have an easy way to find the most common upgrades for each product type.  You know, the kind of questions you guys, Doc, and PJ are always answering for folks.  There seems to me three or four common upgrades for every piece of Bottlehead gear.  Things like coupling capacitors, resistors in the signal path, bypassing specific electrolytic caps, or upgrading the volume pot.

I don't hesitate to ask questions on this board because I know that there will be lots of helpful replies.  Its not that I don't want to ask, but since I have been reading the posts here (pretty much every day since I built my S.E.X. kit) I have seen the same questions asked over and over.  If there were a sticky post in each product's forum page with the info described in my original post you wouldn't have to keep answering the same questions.  At most, just point them to the sticky post.  I know you guys love to help others so maybe you don't want such a page posted because you really want to keep answering those posts.  I'm perfectly fine with that, I just thought it might offload some of the elementary questions and let you focus on the more challenging upgrades like adding chokes, etc.

Also I fully understand and support the view that all kits should be built stock first and then upgraded as the owner sees fit later.  It is much easier for you guys to troubleshoot someone's build if they are following the manual exactly.  And I realize that having an upgrade page posted would tempt people to build the kit with upgrades in place.  But I also believe the people who choose to do that will do it regardless of reading the info from one page or spending hours searching the forum for the information they need.

I'm not going to be upset if these pages are never created, that is totally up to Doc.  I just wanted to make the suggestion.
I look forward to reading your replies and suggestions too.

Ken

[Grainger49]

In Bottlehead gear the biggest upgrade is always whatever C⁴S boards they make for your product.  This will be a three but usually is complex enough to cost more than capacitors, but not always,.

The next most dramatic upgrade is improved iron.  This can be pricey, more than the C⁴S boards, but the difference is meaningful.  I'd say a 2.5.  (1, 2, & 3 are not enough of a range for me)

You can also add chokes (iron) to the power supply of most products.  It is usually under $20 for just a power supply choke and is a noticeable improvement.  Say a 2 which makes it a good bang for the buck.
Good resistors, boutique if you will, are $4-6 each.  Really great resistors are $18 each.  So just a few resistors are relatively cheap but not as much change as capacitors.  I'd say the resistors are a 1.5-2.

Replacing a volume control is a "whole 'nother animal."  They are $20-150 and can make sound cleaner, clearer.  Probably a bigger difference than changing audio path resistors.  I haven't done this so I can't tell you my estimate of improvement.

As I posted above, capacitors start at about $6 and go up, way up.  But they make pretty dramatic differences.  I'd make them a 2 and you can get the KK Teflon caps (only in low values) really cheap.  The Auricaps, a perennial favorite for Bottlehead equipment, are on sale at Parts ConneXion. 

Then you get to tube rolling.  I started rolling FP tubes and ended up with CV4003 Mullards for $60/pr.  They were the best but there were others that were much less expensive that came pretty close.  I use the cheaper ones more often.