[Brinkman]

Jim,

A while ago you responded to a question about the Bugle:

Best place for bypassing is right where the signal is (keep current paths short), and that's C8 and C11.

Really, there's not much you can do with the standard Bugle to improve it.  Aside from a chassis and better connectors, the only improvement would be with C3, C2, C1 locations, and the recommended parta are really quite good.  Or you can change opamps.  Some people like the OPA2604.  You could lose the sockets too. 

Seeing as the Ripper circuit is based off the Bugle circuit, would what you said about bypassing caps on the Bugle apply to the Ripper (C8 & C11 on the Bugle corresponding to C16 & C19 on the Ripper)?

What about upgrading Bugle C3, C2, and C1 locations; would it hold true for Ripper caps C25, C26 & C4? Could upgrading Ripper caps C23, C27 & C28 also be considered? I'm not thinking anything too crazy, just some relatively inexpensive Sonicaps and a Mundorf in the output cap (C27).

I also a curious about opamp rolling. Are opamp positions 5 & 6 the only ones safe for rolling? And lastly, if I do a cap bypass across the pins of my opamps, would a .1uF polypro cap be a good choice?

Best,
Benjamin

[hagtech]

The RIPPER uses the same basic phono circuit as the BUGLE.  Any suggestions made to the BUGLE will apply to the RIPPER.  Except that the plastic box is pretty small, you don't have a lot of physical headroom to fit things.

jh

[Brinkman]

Thanks Jim.

I will rummage through the posts here regarding any Bugle upgrades and assume they will work for the Ripper.

I did, however, have some reservations about making these assumptions on my own, seeing as the Ripper has extra caps, opamps, and a DAC.   

Thanks for the response! I can't wait to share my experience building & blinging-out the Ripper.

Best,
Benjamin

[xlrider]

Jim:
Can The Ripper, be modified for cartridge loading?
If so, where would you recommend soldering the resisters?

What type of resister, would be the best?  (1/8 watt 5% carbon
film resistors)?

What is the input capacitance, of the ripper?

Tim

[hagtech]

You have to swap out the 47k5 input resistors.  Use metal films.  Not carbon.  Input capacitance probably same as BUGLE, roughly 15pF.

jh

[xlrider]

Jim:
Thank you for your reply. You mean, swap out the 47.5k resisters?
I don't want to keep bothering you with questions, I plan to order the Ripper.
But, I think I will be using a Grado cartridge, on a Technics 1210M5G, which has a 100pF cable capacitance.
Using your cartridge capacitance page:
45mH = cartridge inductance
115pF = total capacitance
Ropt, would be 19.8k
Would I add that value, to the 47.5k resisters?
Thanks
Tim

[hagtech]

I would listen first, before playing around with loading.

jh

[ecir38]

Thanks for the response! I can't wait to share my experience building & blinging-out the Ripper.

Best,
Benjamin

Benjamin, how are you coming along with this? Wondering what you came up with for upgrades.

[Brinkman]

   I received the Ripper as a present from my girlfriend on my birthday (Feb 22), and so far I've ruled out mills wirewound as resistors in the power supply, due to the fact that the resistor bodies would overhang their installations and thus result in excessive lead lengths. I cannot prove it mathematically, but my intuition makes me think it would be silly to spend extra on components that would have to be installed in such a manner. So the power supply will use stock resistors.
   One of the major hurdles to overcome with a modified Ripper is the chassis. The underside of the PC board doesn't provide a surplus of clearance for bypass caps, and the design is so compact that any deviation from stock is likely going to find you looking for room where is doesn't exist. That said, I want to say that I seriously considered (and still may consider) installing the Ripper in an old wooden cigar box. We'll see.
   I'm still contemplating which caps to bypass; according to Jims advice regarding the Bugle, C16 and C19 are definite candidates. C35 also seem likely. Additionally, I intend on installing a bypass cap across all op-amp positions. The benefits of this are documented elsewhere on the internet. When I post my progress report, I'll let everyone know exactly what I have done.
   For the analog schematic, I intent on using PRP resistors everywhere, with the possible exception of vishay nudes in key positions. Again, I'll report what I do.
   As for op-amps, I have several to roll. The Burson discreet opamp is the most robust (large-sized) and would require chassis alteration, whereas the audiocom AD825 seems well-reviewed and is more compact. Other op-amps include: AD826, AD827, OPA2228, & LM4562. The procedure I use to assign the placement of each will also be documented.
   I plan on ordering parts for and constructing both my Ripper and Clarinet simultaneously, so please be patient while I contemplate their individual construction. Also, I have a 4-month-old newborn son to attend to, so my DIY time is at an extreme minimum. I'm sorry for any tardiness.

Best,
Benjamin

[Brinkman]

You have to swap out the 47k5 input resistors.  Use metal films.  Not carbon.  Input capacitance probably same as BUGLE, roughly 15pF.

jh

I forget to mention in my last post: for the input resistors (R34) and output resistors (R43) I plan on using Audio Note tantalums. I would only use carbon resistors in a tube-based circuit.

[Brinkman]

My current plans for the Ripper are as follows:
ALL audio resistors will be Vishay nudes. This alone is a $200 upgrade. [EDIT: ended up closer to $300.]
EQ & coupling caps are either Obbligatos or Audio Cap Thetas (choices were dependent on the values available) [EDIT: caps are a mix of Obbligatos, Multicap RTXs, Mundorf Supremes & Mundorf ZNs.]
Output caps will be Mundorf Supremes.
Power supply will be stock. [EDIT: Caddocks will fit. Electrolytics might be upgraded.]
Polpropylene bypass caps will be placed across op amps to lower the noise.
Undetermined brand of bypass caps for power supply decoupling. Foil or polypropylene. Any suggestions? [EDIT: may also bypass CODEC w/ ceramic caps.]
I will be buying a pair of Grado headphones (325i) to help with op amp rolling (I have a bunch) and quiet listening sessions. [EDIT: will go with cheaper Grados...]

So, that's about it. Just waiting on my tax returns, as they will fund both the Vishay resistor and headphone orders. Can't wait. [EDIT: tax returns went to baby. Still working on the Ripper]


Best,
Brinkman

ADDENDUM: In light of the fact I may go with a homemade wood chassis, I am free to upgrade the gain pot. Also, it occurred to me that some RF/LF blocking foil would lower the overall noise, so this is under consideration. Overall, this has already been an incredibly educational build.

[Brinkman]

Jim,

You have remarked that power supply bypassing in the Bugle (and by extension, the Ripper) is only advantageous if done correctly (with short leads) right where the signal is. In the case of the Bugle, these points are C8 & C11, in the PS decoupling. For the Ripper, the supply decoupling is different; there's C16 & C19 which correspond to C8 & C11 on the Bugle, but there's also C15 & C18 decoupling. Is there anything to be benefitted by bypassing these as well? I'm thinking of using some small .1uF polypro caps, nothing exotic.

Additionally, I was considering extra bypassing on the ground caps (C29, C30, C35-C39) of the CODEC with 1/100 value ceramic disc caps (.01uF discs on the 1uF caps, .1uF discs on the 10uF caps). Or would I just be better off shielding the inside of my Ripper with the RF/LF foil that Texas Instruments makes?

Thanks for your support!

-Brinkman

[hagtech]

Ok, the correct answer gets complicated.  And it is imperfect.  But mainly the portion of decoupling that has to be very close, right next to the opamps is the small capacitors that cover the RF frequencies.  The electrolytics which handle power supply frequencies can be farther away.  There are also different reasons for decoupling.  Sometimes it is for stability, sometimes for sonics.  Depends all on the circuit. 

jh

[Brinkman]

Thanks Jim.
But what about this question:

Additionally, I was considering extra bypassing on the ground caps (C29, C30, C35-C39) of the CODEC with 1/100 value ceramic disc caps (.01uF discs on the 1uF caps, .1uF discs on the 10uF caps). Or would I just be better off shielding the inside of my Ripper with the RF/LF foil that Texas Instruments makes?

I apologize if you actually answered that question in your response, but if you did, it went over my head. Like I've stated elsewhere, my EET courses don't begin until fall.

Anyhow, I'm trying to get the best in sonics and stability, so any extra performance I can eek out of the Ripper is for the better.

-Brinkman

[hagtech]

It's not going to help.  You have to be careful when paralleling ceramic capacitors, as you end up introducing a parasitic resonance.  The good news is that I've already solved the issue for you.  Turn the board upside down. You'll see a pair of surface mount capacitors.  They perform the top end decoupling for the chip.  For those frequencies, you have no choice but to use RF surface mount parts.  Leaded capacitors will not work.  Also very layout specific.

jh

[Brinkman]

Jim,

I've been looking at my Ripper PC board for months now and saw what I thought was a couple globs of solder on the bottom. Now I see two miniature capacitors. 

Amazing. I really do need glasses!

Thank you!

-Brinkman

[Brinkman]

Jim,

The upgraded capacitors I purchased for locations C23-C28 are larger in size (physically) than the ones specified in your BOM. In order to install them, I will need to use a few tricks (installing on both sides of the board, DIYing a larger chassis, elevating the caps slightly above the resistors) which in some cases means longer leads than usual, but none longer than a couple centimeters. Even if I heat shrink these leads, will I be negating the advantages of my upgrades by introducing irregularities/noise?

On locations C25, C26 & C28, where the capacitor is connected to ground, is it better to have the longer lead be the one to ground?

Also, know any tricks for reducing the diameter of a lead? I'm thinking very fine steel wool and a careful exertion of elbow grease. Or worst case scenario, connection via solder glob .

Thanks,
Brinkman

[hagtech]

Indeed, a lot of the big audiophile caps will not fit into a RIPPER chassis.  Not much you can do about it.  If the leads are stranded, shrinking diameter is easy.  Otherwise, not sure.

jh

[Brinkman]

Indeed, a lot of the big audiophile caps will not fit into a RIPPER chassis.  Not much you can do about it.  If the leads are stranded, shrinking diameter is easy.  Otherwise, not sure.

jh

So today I traced out the Ripper PC board on paper (to scale) and after figuring the various component arrangements, I think I have a workable plan of attack for fitting large caps on the board. It will be a row of caps on top, and a row of caps on the bottom. The one concession that is necessary is that I cannot use the stock chassis, so I will make one of my own out of wood (probably douglas fir). As for the diameter of the leads being oversized, I am going to experiment with various sanding materials to see if I can carefully thin out the leads without breaking them or damaging the capacitors.

I will keep everyone updated to know how it goes.

-Brinkman

[Brinkman]

Hey Jim,

Two quick questions about the Ripper (my chassis is oversized):

1) I've compared the Ripper schematic to the Bugle Pro schematic (which I also have the parts for) and noticed that the Ripper and Bugle use the same value resistors and caps for the EQ section. Does this mean I can wire the same Turnover and Cut controls & associated components into the Ripper circuit in the same manner as they're wired into the Bugle Pro?

2) If I wanted to optionally bypass the RIAA EQ for line-level use, could I just install a second set of inputs and wire both sets of inputs through a DPDT switch wired to both R34x and C24x?

-Brinkman