Guest David H Posted September 6, 2015 Share Posted September 6, 2015 Here is a video link to the New Record Day review of the ampsandsound Casa Blanca's and Stereo 15 Nice work Justin, it's paying off. Dave https://www.newrecordday.com/amps-sound-casablanca-stereo-15-review/ YouTube link https://www.youtube.com/watch?v=gLJOKXdu_sY 2 Quote Link to comment Share on other sites More sharing options...
Tarheel Posted September 6, 2015 Share Posted September 6, 2015 Congrats Justin. A very good review! Quote Link to comment Share on other sites More sharing options...
joessportster Posted September 6, 2015 Share Posted September 6, 2015 Good to see Justin, the press is finding out what we already knew 1 Quote Link to comment Share on other sites More sharing options...
TasDom Posted September 6, 2015 Share Posted September 6, 2015 Great review however that did not help me to resist the urge to try tube amps. Congratulations Justin! 1 Quote Link to comment Share on other sites More sharing options...
justinsweber Posted September 6, 2015 Share Posted September 6, 2015 Thanks guys. Working at it slow and steady as they say. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted September 6, 2015 Share Posted September 6, 2015 Congratulations justin... nary a foul word was uttered. Justin, what are the effects or compromises one has to take into consideration when looking at point to point versus the integrated circuit board? Quote Link to comment Share on other sites More sharing options...
jimjimbo Posted September 6, 2015 Share Posted September 6, 2015 Justin, great reviews!! Wondering if you could elaborate just a bit on the rectifier tube change-out that would change the sonic properties? What would the choices be, and would it necessitate changing any of the other tubes on the unit? (Stereo 15 SE). Quote Link to comment Share on other sites More sharing options...
Guest thesloth Posted September 6, 2015 Share Posted September 6, 2015 Wondering if you could elaborate just a bit on the rectifier tube change-out that would change the sonic properties? What would the choices be, and would it necessitate changing any of the other tubes on the unit? Changing the rectifier tube will do mainly three things. Increase or decrease current draw on it's heater filament. No change in sound. Increase or decrease HT voltages. This could increase or decrease power slightly. Since it's Class A the current draw remains fairly constant so the increase or decrease series resistance shouldn't matter. No aubible difference. Really changing the rectifier for this amp shouldn't yield any sonic differences. A 5U4 will come up to voltage much faster then a 5AR4, with no load from the other tubes bacause they are not warmed up there will be increased in B+ voltage. I assume the PS capacitors are rated high enough to compensate for this. If the capacitors are rated for the higher voltage of the onloaded power supply then I would go with the NOS 5U4 and they should last a lifetime, especially the old Tung-Sols. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted September 6, 2015 Share Posted September 6, 2015 Justin, what are the effects or compromises one has to take into consideration when looking at point to point versus the integrated circuit board? Since my views are often considered somewhat heretical, I'll give you my thoughts while you're waiting for Justin to respond. Sonically, there should be no difference between point to point wiring and a pcb. If I constructed one of Shannon Parks' or Pete Millett's amps using my point to point techniques, and using identical components, it would sound the same. The big issue is labor intensity, and cost. Stuffing a pcb and soldering the components in place can be a very fast process for an experienced builder (you should have seen some of the assemblers at the power supply company crank out orders for 25 or 30 identical boards, many of which used surface mount components and had to be done under magnification- amazing skill was demonstrated). I would venture that Justin's amps should take no more than an hour or two tops to stuff and solder. Creating the same circuit point to point would take considerably more time. Obviously, pcbs are more cost effective when one wants to get the job done as quickly as possible, and especially if having to pay someone for their labor. Repairs, when needed, are much more of a pain with pcbs and require experience in reworking if one is not to damage the fairly delicate board traces or even crack the board itself (the quality of pcbs can vary hugely- one has to hope that the board used is mil-spec at the very least). This also often prevents the end user/hobbyist from doing his own repairs or enjoying the popular pastime of rolling capacitors or resistors. Point to point amps are much more of an artistic expression as the electromechanical layout usually has to be developed at the bench instead of on the computer. It is often used more by the boutique amp designers than those going for higher volume. Mechanically, the point to point amps are usually as close to indestructible as one can get. If repairs are needed, it is easy to desolder a component and install the replacement, and can often be done by one with hobby level experience. The same for capacitor and resistor rolling. This is one reason why even professional restoration of the vintage amps doesn't usually cost a vast fortune for labor. Contrast that with restoring a device like the Lafayette KT-600 preamp which is built on a pcb. That's far more costly, and many restorers won't be bothered with such a project due to the amount of time required (and owners would probably faint when they are handed the bill for labor). So, to sum up, sonically there should be no difference. In terms of cost, and build time, it's far less expensive to offer a pcb based product than one which is point to point constucted. Maynard 1 Quote Link to comment Share on other sites More sharing options...
derrickdj1 Posted September 6, 2015 Share Posted September 6, 2015 It is nice to see the review and know that they are talking about one our members. Quote Link to comment Share on other sites More sharing options...
MyOwn Posted September 6, 2015 Share Posted September 6, 2015 Sonically, there should be no difference between point to point wiring and a pcb. Ditto This This is from ampsandsound website Point-to-point wiring would allow for streamlined building, but our PCB’s provide superior grounding and noise isolation, with the result that we have realized and improved upon the sonic characteristics of the great amplifiers of the 50’s and 60’s. Quote Link to comment Share on other sites More sharing options...
Lemon string Posted September 6, 2015 Share Posted September 6, 2015 congrats to Justin, Nice review! Also Im a big fan of the New Record day stuff so it was cool to see this. Quote Link to comment Share on other sites More sharing options...
Guest David H Posted September 7, 2015 Share Posted September 7, 2015 Justin, what are the effects or compromises one has to take into consideration when looking at point to point versus the integrated circuit board? Since my views are often considered somewhat heretical, I'll give you my thoughts while you're waiting for Justin to respond. Sonically, there should be no difference between point to point wiring and a pcb. If I constructed one of Shannon Parks' or Pete Millett's amps using my point to point techniques, and using identical components, it would sound the same. The big issue is labor intensity, and cost. Stuffing a pcb and soldering the components in place can be a very fast process for an experienced builder (you should have seen some of the assemblers at the power supply company crank out orders for 25 or 30 identical boards, many of which used surface mount components and had to be done under magnification- amazing skill was demonstrated). I would venture that Justin's amps should take no more than an hour or two tops to stuff and solder. Creating the same circuit point to point would take considerably more time. Obviously, pcbs are more cost effective when one wants to get the job done as quickly as possible, and especially if having to pay someone for their labor. Repairs, when needed, are much more of a pain with pcbs and require experience in reworking if one is not to damage the fairly delicate board traces or even crack the board itself (the quality of pcbs can vary hugely- one has to hope that the board used is mil-spec at the very least). This also often prevents the end user/hobbyist from doing his own repairs or enjoying the popular pastime of rolling capacitors or resistors. Point to point amps are much more of an artistic expression as the electromechanical layout usually has to be developed at the bench instead of on the computer. It is often used more by the boutique amp designers than those going for higher volume. Mechanically, the point to point amps are usually as close to indestructible as one can get. If repairs are needed, it is easy to desolder a component and install the replacement, and can often be done by one with hobby level experience. The same for capacitor and resistor rolling. This is one reason why even professional restoration of the vintage amps doesn't usually cost a vast fortune for labor. Contrast that with restoring a device like the Lafayette KT-600 preamp which is built on a pcb. That's far more costly, and many restorers won't be bothered with such a project due to the amount of time required (and owners would probably faint when they are handed the bill for labor). So, to sum up, sonically there should be no difference. In terms of cost, and build time, it's far less expensive to offer a pcb based product than one which is point to point constucted. Maynard Nicely done. Quote Link to comment Share on other sites More sharing options...
Schu Posted September 7, 2015 Share Posted September 7, 2015 (edited) When spec'ing and building a PtP amp, does one take into consideration wiring gauge and material type? Can one change those elements on an integrated circuit board by varying the screen printing... or is this all academic and non effectual on sound quality. Edited September 7, 2015 by Schu Quote Link to comment Share on other sites More sharing options...
Guest thesloth Posted September 7, 2015 Share Posted September 7, 2015 When spec'ing and building a PtP amp, does one take into consideration wiring gauge and material type? Can one change those elements on an integrated circuit board by varying the screen printing... or is this all academic and non effectual on sound quality. Yes a good engineer will take all that into account. When looking at a schematic it isn't shown but engineers know that there will be parasitic capacitance etc..... Quote Link to comment Share on other sites More sharing options...
justinsweber Posted September 7, 2015 Share Posted September 7, 2015 Hey guys, On a few notes. I do think there are changes to sonic sig of an amp with rectifier changes. I make this statement as a personal belief, not one intended for debates. The Stereo 15 is setup to run 5AR4 and 5U4s without issue. I prefer 5U4s for the decreased B+ which is kinder to the less reliable new EL84s. Additionally, I have lost many a new 5AR4s, the NOS 5U4s are very accessible/high value and provide the user with a reliable US NOS tube. Re: PtP vs PCB. For me the choice was for repeatability. We have 3 people here wiring things up… I was seeking the ability for each to come out exactly the same. The PCBs used are high quality, thick, double sided with heavy traces. I find repairs/changes to be really easy as you can decoder/wick the solder out easily and replaced with the value of the part labeled below the part. Ive seen a lot of really good PtP wiring… cant calm to be one capable of doing it. However, Ive also encounter problems with PtP wiring too. Several years ago we did 3 300b amps hoping to prototype and start building. The circuit was super popular and well thought out, but we encounter a hum… spent 20+ hours trying to figure out what was going on. Ultimately, the power supply caps were faulty. Getting certain values in axial was difficult and I let go of the project. Getting consistent parts has been significant easier when intended for PCB. The style of construction I hold in the highest regard is via turret board. Rogershighfidelity does this… Marantz, quad and Mcintosh did this… The build time would significantly increase which would make the amps unsellable… least by me :-) Re sonic… Im not sure PCB aren’t the quietest method. If all things are equal there shouldn’t be a difference, but as always parts, circuit and builder effect implementation. Quote Link to comment Share on other sites More sharing options...
tube fanatic Posted September 7, 2015 Share Posted September 7, 2015 (edited) When spec'ing and building a PtP amp, does one take into consideration wiring gauge and material type? This is a subject which can be debated until long after the cows come home. Sure, wire gauge has to be chosen in regard to the current passing through it, and its insulation has to be rated for the voltage it will have to handle. Where the debate comes in is whether the type of wire and insulation makes any difference. Some claim that silver plated wire sounds better than plain copper, and that the number of strands which comprise the wire, or its insulation, affects the sound. There's a guy on another forum who claims that he can hear differences in wire length of only 1/8" and has specific lengths, gauges, and insulation types which he uses for specific functions. I take what I consider to be a practical approach and usually use #22 wire for just about everything, the exception being filament wiring with a heavy current draw in which case I use #20. Generally, I use wire with teflon insulation so I don't have to be concerned about the insulation "crawling" if I have to apply some extra heat to a connection. That type of wire is usually silver plated copper and I can't say it sounds any different from wire which isn't silver plated. Perhaps Justin, and others, can comment on their experiences with this. As with capacitor dielectric materials, there is no right or wrong answer or universal recommendation. Maynard Edited September 7, 2015 by tube fanatic Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted September 7, 2015 Share Posted September 7, 2015 In one instance, the Ampsandsound website refers to its "design partners" for assistance in the development of one of its products. Circuit design is something that I find much more interesting than aesthetic implementation or outward appearance. Who are these "design partners" and with what specific aspect of design are they concerned? Certainly I'm familiar with Shannan Parks, and, even more so Alan Kimmel. Why was reference made to them here? Quote Link to comment Share on other sites More sharing options...
Guest David H Posted September 7, 2015 Share Posted September 7, 2015 (edited) Several years ago we did 3 300b amps hoping to prototype and start building. The circuit was super popular and well thought out, but we encounter a hum… spent 20+ hours trying to figure out what was going on. Ultimately, the power supply caps were faulty. Getting certain values in axial was difficult and I let go of the project. Although there were some issues with the turret board 300b project, it was a lot of fun. I ended up using radial caps in my build due to availability. Justin was a huge help with this build as was NOS Valves and of course my Father. http://nebula.wsimg.com/7c3db1ab780927c7bd661a993aa621b5?AccessKeyId=0A27A251977F2A00A2F4&disposition=0&alloworigin=1 Sorry for getting off topic, Back to the review. Dave Edited September 7, 2015 by GotHover Quote Link to comment Share on other sites More sharing options...
erik2A3 Posted September 7, 2015 Share Posted September 7, 2015 From what supplier/s are the boards sourced, and who is the manufacturer? Quote Link to comment Share on other sites More sharing options...
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