TBDD-500, TBDD-Rack, TB550A, TB2S

[horvitz]

Cool, got the order.  Thanks!  That will ship today.  If you end up wanting to do any sort of mod, let me know and I'll help you work out the best way to do it.  Then maybe we could put together a bit of a tech note for anyone who wants to do the same in the future.

 

[rhythminmind]

Any help would be much appreciated. I have a d-scope at my disposable to test the results. Looks like a resister value change to compensate for the 2.2uA 990c input bias is whats needed. Any suggestion on values?

 

[horvitz]

I would suggest that you build it as-is first and just see how it goes.  If then you think it needs something, we would probably want to direct a question to JH and see what is recommended.  I would imagine that it wouldn't be the first time they have been asked about stuffing a 990 into a 550A.

 

[rob61]

Payment sent for 2 kits.

 

[John Hardy]

A little quick looking shows me a few comments from John Hardy on exactly this topic:

http://www.recordingchannel.com/api-2520-where-can-i-get-some-462619.html#9

I'm not sure where that text attributed to me originated, but it appears that someone put it in a blender before posting it (some type of adverb/adjective adder). A few choice quotes:

the resistors were in the megaohm blatantly range.

these resistors would eloquently compensate

I supernaturally have great respect for

When factually using a 990

John Hardy
The John Hardy Co.
www.johnhardyco.com

 

[horvitz]

Ha.  Yeah, I did feel a little weird reading that.  A kind of auto-generated spam prose thing going on.  I just did a search on Google for the first line there and removed the "blatantly" and came up with this:

http://www.audiobanter.com/archive/index.php/t-10845.html

A little better, I'd say!  It seems like that recordingchannel.com topic basically scraped, imported, and spamified most of the thread from audiobanter.com and attributed all the posts to bogus accounts.  Very weird.  I bet it drives ad impressions nicely.

  Brian

 

[John Hardy]

Ha.  Yeah, I did feel a little weird reading that.  A kind of auto-generated spam prose thing going on.  I just did a search on Google for the first line there and removed the "blatantly" and came up with this:

That is much better.

I sent an e-mail to the folks at recordingchannel to ask them what is going on there. There are several messages of mine with the same type of alterations. They either need to correct them, remove them, or make it clear that the content of the messages has been modified without the author's permission.

Thanks.

John Hardy

 

[Winetree]

Paid for one kit. Hoping you'll have another in month.

 

[horvitz]

Thank you!  That will ship in the morning.

  Brian

 

[Songguy]

Hi Brian,

Would you mind giving a quick recap on the filter switch. Ie what happens when switch is up "filter" vs down position. And why one would choose one position or the other.

Sorry for the super noob question.
Cheers,
Chris

Ps thanks again for all your troubleshooting help.

 

[emrr]

have a look in the build thread, there's a response chart for the filter. 

 

[horvitz]

Also some additional info at the beginning of this thread.

  Brian

 

[Winetree]

Another child is born. Will test it out monday.
I understand what the filter does graphically
So does this mean when you have all 3 cut and boost pots zeroed out,
by engaging the filter, the whole EQ becomes one bandpass filter?
A quick and easy flick of the switch instead of using the hi and low bands to roll off.

 

[rickc]

the bandpass filter has different curve shape than the eq filters in the 550. so although the curves for the bandpass filter stop (looking at the api supplied curves) at -15dB or so, in reality, they keep on going, whereas the low-eq knob, in shelf mode, goes down to the shelf frequency and levels off. The filter switch is like having simultaneous HPF and LPF buttons on a channel strip, and they simultaneously restrict the bandwidth of the input signal. The slope of the curves are also different.

 

[horvitz]

Just a quick note that I'll be travelling from 4/17-4/24 so there will be no shipments during that time.  Any orders in by about 2pm EST tomorrow I should be able to get out before I leave.

 

[horvitz]

A number of you have told me that you'd like to be notified when stock is getting low, and we're officially there!  10 left now, and I have no immediate plans of doing another run since I'm working on something else at the moment.  Of course given how erratic sales are, this stock might last two weeks or two months, but I wouldn't wait too much longer if you've been putting it off.

Thanks for all your business everyone!

  Brian

 

[qmp audio]

10 left now

... 9 left now  ;D

 

[horvitz]

Six Five actually!

 

[frederickalonso]

Ordered mine yesterday. Looking forward to publish some pics when soldering.

Thanks mate, always wanted to have a self-builded high end Eq ;-)

 

[horvitz]

Thank you for your order!  Have fun with the build.

Just three left now!!