John Curl's Blowtorch preamplifier part III

Status
Not open for further replies.
I am somewhat interested in how many mods can be made to the Parasound integrated amplifier in order to improve it. Gold plated Molex sounds good. Molex in general is marginal, but sometimes necessary to enhance future repairability of power amps. You won't find a Molex in a CTC Blowtorch, BUT it costs 10 times more!
I always know that 'cost effective' designs made by Parasound (and almost everybody else) can be improved. This integrated amp is at the bottom of designs where I can be even mentioned for this very reason. However, this website is useful where a good design can be improved with better connectors and sometimes, parts. My more expensive stuff, where I have more control over layout and connectors are harder to upgrade. So let's see what you guys find that is practical and useful in making this design better!
 
I am somewhat interested in how many mods can be made to the Parasound integrated amplifier in order to improve it.
Cool.
I plan on taking Bob on a stage by stage journey of enlightenment, hopefully some rubs off onto others, JC I know you well enough to know that you are receptive to 'new' understandings.
Gold plated Molex sounds good. Molex in general is marginal, but sometimes necessary to enhance future repairability of power amps. You won't find a Molex in a CTC Blowtorch, BUT it costs 10 times more!
Totally different classes of machines, you have no need to justify. :).
The Taiwan design/manufacturing school is very much evident in the HINT design which is good on a whole bunch of levels.

I always know that 'cost effective' designs made by Parasound (and almost everybody else) can be improved. This integrated amp is at the bottom of designs where I can be even mentioned for this very reason. However, this website is useful where a good design can be improved with better connectors and sometimes, parts.
Sure, I/we? understand this is entry level all-in-one hi-fi product from Parasound but it's got all the fruit you could want, seriously.
Hook up a USB connected laptop and you have endless music....perfect.


My more expensive stuff, where I have more control over layout and connectors are harder to upgrade. So let's see what you guys find that is practical and useful in making this design better!
Sure, if they are going use your name you deserve a final sign-off listen.....how well does that work in practice ?.

My eye is on what can be implemented easily in current production for this kind of product to improve the satisfaction factor for the household.....that's what sells !.
So far I see some physical changes that can be performed and confirmed easily by Bob....once that is done we could collectively take a closer look at the rest. ;).
There are varying reviews of Bob's machine, mostly highly positive BUT some in line with Bob's finding that it's not quite right.
IIRC Bob's complaint is that the Hint is too polite and doesn't have the punch/bite of his Pioneer equivalent which looks to be a remarkable machine for the price.
I see elementary but well intentioned mistakes in just the wiring so far....there are rules to energy input and energy output connections and energy routing to be obeyed, this is a core of my researches.


Dan.
 
Bring it Dan! All input is appreciated
Ok, Lesson 001 of 101 lol is coming.
When I put everything back together I’ll be setting up the system in its original tune and using it as reference for the new stuff.....ought to be fun (probably not so much for the wife!)
It keeps you at home at night, the wife ought to thankful lol......and besides when you get the sound system singing right she might find ways of showing you how more thankful she is lol.
Vac I detect a bit of sarcasm there but what I gleaned from the bits of info I did get from JC (whether direct or indirect) there were things about the Hint that happened in production that weren’t to his liking......I suppose that happens in the design world all the time?
Designers get screwed down to the last half a cent for typical/high volume consumer designs.....I see a little more freedom in this Parasound design BUT up to a point.
Different cultures have different eyes for designing (and different supply chains), the Hint is pure Taiwan, and there is something good about that in my findings/long experience.
Bob, I trust your ears and I think I understand your ears (ie the sounds of your findings), this should be a run of fun experiments you can perform in your shop and confirm on the shop KLH's.(which model ?)
You have a magnifier lamp and a decent soldering iron ?.
You ought to be able to make this amp/interface sing, and it ought to be near to zero cost, let's have some fun.


Dan.
 
Last edited:
parasound ferrites 02.jpg

Lesson 001
Any material in immediate electrical series or in physical proximity of the energy supply (in this case the power transformer primary) will cause influence of downstream stages with maximum influence according to electrical and physical proximities and decaying with electrical and physical distance.
Stages are defined as transducers, wires, connectors, substrates/dielectrics, and passive or active devices.

IME the series inductors marked in the pic cause unnatural subjective mayhem and need to be removed...... wire bypasses will not do but could be tried as a first experiment in hearing stage by stage changes.
First experiment is to fit a couple of non directional links flat bridging or high looping across the vacant inductor pads.........a length of stripped Cat5 wire looped back and twisted is plenty of conductance for the purpose and in this environment is said to be non-directional conductance.
Enameled wire of similar gauge similarly implemented is also perfectly suitable and is indeed another subjective experiment.
Those non directional 'naked' wire loops are open to application of all kinds of modifiers, that's part of what Goop is about.
In this case the in all ways identical loops are providing a 'reset' in the noise/dithering of the energy flow equation that serves to influence the whole system all the way to the air in the room. ;).
IOW I'm saying those ferrites so close to the transformer will cause ferrite system sound and although well intentioned are a fundamental sonic mistake IME.....IOW IME/IMO ferrite sound sucks .
I encourage you to try this as your first experiment......understand the whole energy equation all the way to your ear nerves is downstream of these neutralising/dithering/balancing links, this is the lesson.

By the looks you could do the ferrite link removal and wire fitment from the top/side, ie no pcb's disassembly required maybe, depends on your skills/tools level but you sound to be pretty handy.
This brings up subject of solder, please promise me that you will obtain/use lead free solder for this procedure, you will thank me in time I am sure. ;).
There is bypassing the voltage selector pcb/switch/connectors as a next stage....or switchable AC polarity flipping maybe.....you would need to buy a few of the appropriate connectors but they are not expensive.
Thanks for the good photos, could we have an overhead shot too please.
Over to you. :cool:.

Dan.
 
Last edited:
Seems like an interesting audible test of room smoothness/evenness or how flat/non-flat the listening position/room. The effect of such nonflatness has a particular sound effect with slow swept tone. Not too surprising but fun to hear.
Yes, it is interesting. I'm experimenting successfully with an IB subwoofer in the corner of my room (supposed to be bad place?) I'm getting a smooth response except for my ever present peak at 40Hz, easily cut and no nulls. What do you do bass wise? Another useful test Sine Burst Tones (20-200 Hz)
 
I'm reminded of Denis Morecroft (of DNM) who hates metal and tries to keep it out of all his products as much as possible
Understand the sounds of the metals (pure elements or in compounds), metals by definition are not to be feared, some metals yes most certainly must be excluded from electric systems or BQP style post filtered at least.
It seems that energy carries subtle record/signature/memory or whatever you wanna call it of it's provenance and this subtle 'modulation' affects downstream systems and their throughput and output.....on a scope/meter/plot we call it noise but it's actually information, system important information actually.
Bob's 'tweaking' of his amp should show up some interesting results.....BTW as I understand him, Bob is way past expectation biases, BS walks as he has said already, if it sounds right or wrong Bob will say so.
Hell, Bob has a lifetime of experience of getting banjos to sound right and knows right sounding playback when he hears it lol.


Dan.
 
Ok.....wow!

Thanks Dan,
Especially for the kind words........my ears have always been my most trusted tool that’s why I reject all these bias bs stories.

I’m just getting onto my first cup of coffee, idk what time it is down under?

What’s your most convenient time to be here?

I’ll have to collect some tools/supplies.....I’m not quite geared up for fine electronics.

Good a time as any, I’ll either sink or swim ......I do have an old parts h/k to practice soldering circuits on first.

Edit......my other reciever a Yamaha R-N803 not Pioneer (don’t want pioneer getting undo credit!)
Bob
 
Last edited:
I always know that 'cost effective' designs made by Parasound (and almost everybody else) can be improved. This integrated amp is at the bottom of designs where I can be even mentioned for this very reason.

I have a listening experience with Halo Integrated (however not with the newer model HINT6). It is not bad, but to me, to my ears, not transparent and accurate enough. IMO it would not be easy to improve it, because as we can see from the photo of inside HINT6

https://www.parasound.com/product-images/hint6_black_inside.jpg

the amp is quite complex and has many modules interconnected together, with quite low cost connectors and wiring. To get high level of transparency, number of circuit boards is to be kept at minimum, IME, and interconnections shortest possible. Especially if we handle small signals in the environment of large mains transformer and charging current impulses into DC filter large capacitors. We have all in one with necessary compromises.
 
I have a listening experience with Halo Integrated (however not with the newer model HINT6). It is not bad, but to me, to my ears, not transparent and accurate enough. IMO it would not be easy to improve it, because as we can see from the photo of inside HINT6

https://www.parasound.com/product-images/hint6_black_inside.jpg

.

Thanks Pavel,

It’s the original Hint not the 6, (same basic thing but 6 has a couple updates) and yes transparency is not a strong point.
Almost as if the leading/trailing edge transients are muffled.

My Weller (soldering iron) died, so I got this one; surprisingly good for the price!

Thanks Zung, I’ll look into it.......should I get the extra set of tips?
 
Last edited:
I'm not questioning your hearing. I'm saying that calling bias stories BS is a bias, probably the greatest one.

As a craftsman I rely on and trust all my senses, I don’t understand how this is any different?

My maternal family is/was very artistic, some on a professional level.......I think the artist is wired differently, more of a connection to things. Idk it’s hard to explain.......but anyway you look at it, bias is just a preference in my book.
 
Ok.....wow! Thanks Dan,
Especially for the kind words........my ears have always been my most trusted tool that’s why I reject all these bias bs stories.
If I like or I don't like a sound I will say so and why which is of course the important bit.....I hear ya when you are describing your gear.
I’m just getting onto my first cup of coffee, what time it is down under?
Lol.
What’s your most convenient time to be here?
Whenever you see me online.
I’ll have to collect some tools/supplies.....I’m not quite geared up for fine electronics.
A bench magnifier lamp if you need it, DMM, a lower powered 110V soldering iron or Varitemp solder station, liquid flux, lead free solder, cotton buds/solvent, desolder pump/desolder braid and you are good to go.
Good a time as any, I’ll either sink or swim ......I do have an old parts h/k to practice soldering circuits on first.
Yeah, learn how to desolder pcb, clean up pcb and refit/new fit parts to boards and tinning wires, single strand, enameled and multistrand.
Edit......my other receiver a Yamaha R-N803 not Pioneer (don’t want pioneer getting undo credit!)
Ok thanks oops, reviews of your Yamaha are consistently good.
Ok, once you are prepped you can progress.
I use solder 99.3%Tin/0.7%Copper as it is a common alloy and I reckon it sounds good, the Parasound should be lead free from factory I expect, make sure to keep all traces of lead totally outside of that box is a primary advice. ;).

Dan.
 
Status
Not open for further replies.