Del Ray Crack

[Mosez]

My Del Ray Crack may as well have been called Midnight Crack II, as Bob Trancho's original Midnight Crack surely was what inspired me to create my own. Here's my build story.

Chassis
I decided to paint the chassis plate, as the grain on the plate was all over the place. Rather than returning it, I primed it and gave it a couple of coats of Krylon Brushed Metallic Satin Nickle. Same treatment for the power transformer bell and the 9 pin socket clamp.

The power transformer itself had a lot of lacquer bunched up on one side, and after sanding it I realized it had to be painted as well - so more primer and a couple of coats of Krylon Brushed Metallic Oil Rubbed Bronze.

Base
The base has the same 45 degree chamfer that Bob put on his Midnight Crack, though mine is pretty rough looking. I'll explain why that is in a minute. I started staining the base with a ebony color water based dye stain from General Finishes. I had pre-raised the grain and knocked it down again with some light sanding with 320 grit, but unfortunately the hard alder wood took the dye only partially, resulting in some serious blotching. I couldn't get it to look right, so I decided to start over which took quite a bit of bleach, white vinegar and sanding. This 'treatment' - especially the sanding did not leave the chamfer unharmed and even after touching it up with the router the angles were not quite as sharp as they initially were.

The second time, I started with Charles Neil's Pre-Color Conditioner - Blotch Control. This stuff works miracles on 'difficult' woods like alder and maple. After that, the ebony dye stain took just fine - 2 coats was more than enough. I started finishing with another product from General Finishes - High Performance Polyurethane Water Based Top Coat but I didn't like that stuff at all, primarily because of the fast drying time combined with the necessity to handle the base while finishing. I then switched to GF Arm-R-Seal Urethane Topcoat and that did the trick. The base has only one coat of Arm-R-Seal and really needs one or two more coats, but that is for later.

Upgrades
I had already ordered replacement hardware from Bolt Depot - all socket button heads in stainless steel to match the contemporary look. A couple of more 'upgrades', sourced from eBay:

- Neutrik locking
- Alps pot (with solder eyes)
- Larger volume control knob
- A variety of 6AS7 tubes. The one pictured is one of a pair of Chatham 6AS7G from the 1950's

Assembly
After the dye stain debacle, I found assembly quite frankly to be a breeze. Upgrading my tools based on tips from other Bottleheads on this forum certainly helped. Specifically, I added:

- Stripmaster Wire Stripper #16 to#26 AWG
- Cardas Quad Eutectic Solder
- Set of cheap (non-medical) forceps

I can't believe I ever did without these. Time savers and lifesavers.

Others had noted that the wire lengths specified in the Crack manual left quite a bit slack so I quickly changed to measuring the wire runs in place. When I was done with the wiring, all resistor values were immediately within limits and so were the voltages. Flipped the chassis plate, plugged in the tubes and on to spinning some CDs in my Oppo.

Impression
My headphones are an old pair of Sennheiser 580s. Extremely comfortable cans and very detailed. After going back and forth between the stock 6080 and Chatham 6AS7G a couple of times, I found the 6080 to be a bit harsh - especially in vocals, very sharp "S-es". The Chathams are smoother, though one of them turned out to be quite microphonic. I'll be rolling in some more NOS tubes to see (hear) which do really well.

Also, my Crack is not dead-quiet as some are reporting. With the volume open beyond 50% a hum becomes audible that increases with volume. The volume open that far is well above acceptable listening level, but still. I thought this might be a function of the open ground connection of my beloved Van den Hul D - 102 III Hybrid, but changing them with continuous ground jacket pair did help somewhat but still left some remaining hum. Same goes for a direct chassis to chassis connection.

Future
I plan on swapping out the coupling capacitors, dropping in two chokes and I have a Speed Ball on order.

Photos
See below for a selection of photos. The full album can be found here.

Del Ray Crack in listening position

Soft glow of one of the Chatham 6AS7Gs

Make no mistake: this bottle gets hot!

Detail stainless steel socket button head hardware and paint job

Painted 9 pin socket clamp

Alps pot

Del Ray Crack guts

Custom built power cord. Double techflex.

Weapons of choice. Full disclosure: the scope is more for show than anything else. Have yet to use it on the Crack.

 

[Grainger49]

There is something very dignified about the look of the black base and the bright nickel top.  It gives the Crack character.  I like it!  And that is the most even braid I have seen in any Crack.

I use my scope to diagnose noise problems.  Looking at the problems sometimes helps me.  The shape of the wave will also point to where in the circuit the problem might lie.

 

[Doc B]

Looks great! By the way that graining on that panel is supposed to be like that, like the finishes metal sculptors do with grinders.

I do it with a metal brush angled 45 to the work one way, then lightly go over it with the brush angled 90 degrees to the first pattern to make sort of a random cross hatch.  I think it looks much more interesting than the old sanding machine graining and doing it in house assures that there are no odd smooth tracks on the top like we used to see when the grainer's sandpaper was dull. As you found one can paint or powder coat it just like the old panels, in fact I think this grain may be a little less deep. Just want to point out that it is not an error, it is my artistic license. We will be reshooting the kits as we can and posting product photos with the new finish.

The trick I have found with alder is several light coats of dye. Though I have pretty much shifted over to clear finishes in the past few years, either a clear water based poly or a few coats of Tru Oil to bring out the grain.

 

[Paul Birkeland]

Also, my Crack is not dead-quiet as some are reporting. With the volume open beyond 50% a hum becomes audible that increases with volume. The volume open that far is well above acceptable listening level, but still.

Dead quiet would be no audible hum on the very highest end of a reasonable listening level.  Beyond this, even with a strong signal to noise ratio, the giant level of signal will also bring up the noise floor to an audible level.

Your build looks great!

 

[Grainger49]

As Paul, above, says the test is at listening levels.  The volume wide open test is a sickness brought to us by audio reviewers.  I don't remember ever having a system that was dead quiet with the volume wide open, most assuredly all my solid state components had some hiss.  (D-W SP-S Preamp, Marantz, Sansui, Crown, SAE, all of them)  Today with tubes from my cartridge to my speaker leads I don't hear hiss or hum even at my loudest listening volumes (somewhere in the 80dB range according to my Radio Shack meter).

Of course none of the products I owned cost in excess of $10,000. 

 

[Chris]

Stunning craftsmanship... I always love how Krylon coats so easily, it is just very nice spray paint to work with..... I also like my D-102 mk3s also... I would be very interested as to how Docs bottlenecks fair in a comparison....

 

[Mosez]

There is something very dignified about the look of the black base and the bright nickel top.  It gives the Crack character.  I like it!  And that is the most even braid I have seen in any Crack.

I use my scope to diagnose noise problems.  Looking at the problems sometimes helps me.  The shape of the wave will also point to where in the circuit the problem might lie.

Thanks Grainer, much appreciated. I'll probably dust of the scope to see if it can help me find the source of the grounding issue. That is, if there is one - based on Paul's comment below.

 

[Mosez]

Looks great! By the way that graining on that panel is supposed to be like that, like the finishes metal sculptors do with grinders.

[snip]

I do it with a metal brush angled 45 to the work one way, then lightly go over it with the brush angled 90 degrees to the first pattern to make sort of a random cross hatch.  I think it looks much more interesting than the old sanding machine graining and doing it in house assures that there are no odd smooth tracks on the top like we used to see when the grainer's sandpaper was dull. As you found one can paint or powder coat it just like the old panels, in fact I think this grain may be a little less deep. Just want to point out that it is not an error, it is my artistic license. We will be reshooting the kits as we can and posting product photos with the new finish.

The trick I have found with alder is several light coats of dye. Though I have pretty much shifted over to clear finishes in the past few years, either a clear water based poly or a few coats of Tru Oil to bring out the grain.

Thanks Doc. I guess I didn't realize the change in artistic design - my apologies. My comment wasn't so much meant as criticism but merely an observation influenced by my expectations and personal taste. Having said that, I quite like the way the paint job turned out. The cross pattern surely provided a good base for the primer to hold on to. 

 

[Mosez]

Also, my Crack is not dead-quiet as some are reporting. With the volume open beyond 50% a hum becomes audible that increases with volume. The volume open that far is well above acceptable listening level, but still.

Dead quiet would be no audible hum on the very highest end of a reasonable listening level.  Beyond this, even with a strong signal to noise ratio, the giant level of signal will also bring up the noise floor to an audible level.

Your build looks great!

As Paul, above, says the test is at listening levels.  The volume wide open test is a sickness brought to us by audio reviewers.  I don't remember ever having a system that was dead quiet with the volume wide open, most assuredly all my solid state components had some hiss.  (D-W SP-S Preamp, Marantz, Sansui, Crown, SAE, all of them)  Today with tubes from my cartridge to my speaker leads I don't hear hiss or hum even at my loudest listening volumes (somewhere in the 80dB range according to my Radio Shack meter).

Of course none of the products I owned cost in excess of $10,000. 

Thanks Paul, and thanks to you and Grainer for the sanity check as well. You raise a good point - none of the (sub 10K) solid state amplifiers and receivers I ever owned and operated were dead quite with the volume wide open. Far from it as a matter of fact.

 

[Doc B]

Yes absolutely, the paint job came out super nice! That of course is the point of these DIY kits, one can personalize them to taste.

 

[Mosez]

Stunning craftsmenship... I always love how Krylon coats so easily, it is just very nice spray paint to work with..... I also like my D-102 mk3s also... I would be very interested as to how Docs bottlenecks fair in a comparison....

Thanks Chris. I considered getting Docs' bottlenecks but I'm afraid my CFO won't approve the expense. It appears that at least in my case, the fully connected ground shield may actually help. The bottlenecks being a kit, you could elect to build it like the D 102 III of course.

 

[Doc B]

I realize a lot of you haven't seen the new aluminum grain finish we are talking about. The first whack at it can be seen on the Tode guitar amp product page. This is a photo of a Tode I built for myself last Friday, with a more representative iteration of the current pattern, and also a Tru Oil finish on the wood rather than a poly finish. Shot with my crappy iPhone camera during this morning's coffee/email/forum workout.

 

[btrancho]

Beautiful work, Daan.  I'm honored that my Crack was you inspiration but your craftsmanship puts mine to shame.  Bravo!

I hope you get as much enjoyment out of your as I do mine.

Bob

 

[Mosez]

Beautiful work, Daan.  I'm honored that my Crack was you inspiration but your craftsmanship puts mine to shame.  Bravo!

I hope you get as much enjoyment out of your as I do mine.

Bob

I don't know about that Bob - especially the wood working was very much a process of trial and error for me. But thanks! For me, the building is at least as much fun as the listening, if not more. Very happy I can tinker with this amp for a while.

 

[Mosez]

With regards to wood working; for anyone interested in taking this to the next level - or just browsing for some basic info - I highly recommend the Wood Whisperer's vast online video and articles archive. This site has very active community - much like the Bottlehead forum, and Marc Spagnuolo will often respond to inquiries himself.

Here's the article on controlling blotching that got me on Charles Neil's pre-color conditioner.

 

[Chris]

Wood Whisperer... hahaha