| LongJohnny |
I am getting a bunch of Burr Brown opamps this week, and will give the forum members very good prices on them.
BB OPA627AP- $12
BB OPA637AP-$12
BB OPA637BP-$12
LM4562, coming early next week, $3/each
Also coming next week
AD825, Probably around $3/each
AD797, also around $3/each
Please email me at johnlot@cox.net for pre orders.
I take paypal.
Thanks,
John Lewman
www.effectsconnection.com |
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| LongJohnny |
I just wanted to do an initial special for those who want to try these out. If you and some friends want to get in on this, I will offer these opamps at
BB OPA627AP- $9
BB OPA637AP-$9
BB OPA637BP-$9
I will ship as many as you buy in the United States for $3, and $6 for international shipments.
Thanks,
John Lewman
info@effectsconnection.com
Thanks, |
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| bequerel |
| Any LM4562 SOIC available? I need several. |
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| PabloS |
John,
Do you still have the OPA627AP's ? I would neeed 5 if you still have them. Let me know the total with shipping and I will use Pay Pal.
Thanks, Paul |
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| LongJohnny |
email me at johnlot@cox.net
I do have the OPA627's in right now.
John |
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| Andypairo |
Hi John,
do you still have AD797?
Regards
Andrea |
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| Jules |
Many thanks for the quick delivery John, I couldn't believe the difference over the stock opamps on my nos dac,
Jules |
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| LongJohnny |
| quote: | Originally posted by jeffry_widjaja
Heiii ... Johny boy
what is different between ad 825 with ad 823
regards
jeffry_widjaja@yahoo.com |
I am not familiar with the 823's, and I will get the AD825's in tomorrow, as today is a holiday. I will test them out and start shipping, so people can post some reviews.
John |
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| bosco381 |
Hi John.
Thanks for the quick delivery and I appreciate your excellent service.
The OPA627s are great!
Regards,
Robert |
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| jeffry_widjaja |
Hii Johnny
what is the code below opa 627bp
thank you |
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| Tolu |
Hi John,
do you have the OPA 627 and 637 still in stock?
Regards
Thomas |
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| Algar_emi |
| Do you still have the AD825? |
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| jeffry_widjaja |
hii Johnny
can i buy opa 627bp just 3 pcs ?
do you still sell it just US$ 9 ?
please ask the shipping cost to jakarta, indonesia
do you receive paypal |
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| dviswa |
Hi Jhonny,
I am interested in 4 OPA627, are they still available?
Regards,
Dinesh |
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| Andypairo |
Hi John, did you receive my amail about the (20) AD797 I bought?
Regards
Andrea |
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| Kip |
| I need 2 OPA627BP if you got them. |
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| korben69 |
Hi !
I need 4 x LM4562MA.
Let me know how to proceed.
Can you supply AD8620 ?
Regards. |
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| SamL |
Hi John
Not sure you got my email. Looking for 2 x Opa627BP in DIL8 size.
Do you have AD745 in SO16 size?
Sam |
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| Tolu |
| Is LongJohnny still alive? :confused: |
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| Mikewong |
Hi Johnny,
Do you still have AD797 in sale? |
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| Andypairo |
| quote: | Originally posted by Mikewong
Hi Johnny,
Do you still have AD797 in sale? |
I bought 20 and none worked. Go figure...
Andrea |
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| jacco vermeulen |
| quote: | Originally posted by Andypairo
none worked. |
As in Deado ? |
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| Andypairo |
Jacco,
would you care to explain?
Cheers
Andrea |
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| jacco vermeulen |
I asked if you mean by "none worked" that all AD797s you bought were fried ?
Kaput, Mertvo, Mort, Muerto, Morto ? |
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| Andypairo |
Unfortunately yes.:bawling: :dead:
Cheers
Andrea |
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| peranders |
| quote: | Originally posted by jacco vermeulen
I asked if you mean by "none worked" that all AD797s you bought were fried ?
Kaput, Mertvo, Mort, Muerto, Morto ? |
Död as in dead.... How dead? No current consumption, very dead? Have you tested an "alive" AD797 also? Is the connection a proven AD797 circuit? |
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| Andypairo |
They were used in a flea regulator (as gyrator) but output was 0V.
Using a normal opamp things worked.
Labeling of the chip was also different from the classic Analog Devices.
Now I'm waiting for some pcs from another supplier.
Cheers
Andrea |
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| peranders |
| Can you show me the circuit in mind? It's possible that this opamp is unsuitable? Have you checked the suitability at all? |
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| Andypairo |
Actually the circuit (pinkfishmedia "flea") was designed around the AD797.
More info here: http://www.acoustica.org.uk/
Cheers
Andrea
BTW Johnny admitted a high failure rate of the batch and made a partial (30%) refund for a 100% failure rate.... |
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| peranders |
| I wonder if the common mode input voltage might be something? the design has only a green LED 1.7-1.9 V and minimum is 3 volt and 2.5 V typical. It might be a design fault? |
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| FastEddy |
See http://focus.ti.com/lit/ds/symlink/opa627.pdf
Note between page 9 and page 13 are some really neat ideas about making this wonderful op-amp jump and sizzle ... Although it is not obvious from the text or drawings, really good performance can depend using a pair of close coupled plastic caps right next to the power supply pins ... this would be in addition to the rail filtering of the power source ... :eek:
(Since the 8-pin DIP package is not yet available, us DIY types with tired old eyes may have to use the TO-99 cans in our circuits ... so don't ignore the PCB layout suggestions on page 9. Also those input diode camps on page 11 are always a good idea if you anticipate that this op-amp will be connected to the outside world = cheap insurance against killing the device from lightning, static or just plain ol' foolishness.) |
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| KP11520 |
Hi FE,
I put these in my CD Player and they sound very nice. Now, AndrewT is helping me with the Decoupling Cap values to make these sound even better (my CD Player was setup for 5534s).
Have you ever Biased these to Class A ala Carlosfm?
Thanks!
Regards//Keith |
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| SamL |
Hi Peranders,
Don't mind me asking an off topic question. From your web site, looks like you have tried AD745. How would you compare it to Opa627? With the adapter shown on your site, can I do a drop in replacement for Opa627? |
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| Andypairo |
| quote: | Originally posted by peranders
I wonder if the common mode input voltage might be something? the design has only a green LED 1.7-1.9 V and minimum is 3 volt and 2.5 V typical. It might be a design fault? |
Hi,
since many boards were built with this schematic I think the design is OK.
When a chip draws 500mA or more I tend to think it is not the chip it pretends to be.
Cheers
Andrea |
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| peranders |
| quote: | Originally posted by SamL
Hi Peranders,
Don't mind me asking an off topic question. From your web site, looks like you have tried AD745. How would you compare it to Opa627? With the adapter shown on your site, can I do a drop in replacement for Opa627? |
I have only hold the AD745 in my hand, not used it for anything yet but I plan to design a RIAA amp later on. Sigurd has tested it though. You may ask him what he thinks. More about it here |
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| Archwn |
This guy cant be trusted anymore.
He sold my friend (who organized a group buy of parts) a bunch of LM4562s and most of them around 90% of the bunch are not working. I bet another 10% would also be lower than standard.
Probably he sells graded or factory rejected items.
And then my friend tried to contact him to resolve the problem. He never replied again since then.
It is not so good is it? to make a profit like this. Selling things only without solving the sale's problem previously.
I've informed Nat Semi on this already and there will be A STRONG ACTION up on him for sure.
He had just made the DIY society a real bad reputation.
So, beware of this guy, my friends. |
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| jacco vermeulen |
| quote: | Originally posted by Archwn
Probably he sells graded or factory rejected items. |
Likely.
What people don't realise is that such is the case with a great many "affordable" semi's.
And has been for ages, semi-conductor companies have a long history of dumping manufacture reject lots, and people have been warned for this on many occasions. |
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| KP11520 |
Hi jacco,
The shame here is that TI has forced many to look "Elsewhere" for the 627s in DIP. They won't be making any, from what they have said, until Spring 2008 sometime and all the reputable Vendors are high and dry! I don't know if this is the situation with the other chips discussed here too.
I wound up getting 12 OPA627BPs from a guy in Massachusetts on eBay with a very high satisfaction score. I just hope they are fine!
Believe me, I would have preferred to buy from DigiKey!
Regards//Keith |
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| jacco vermeulen |
Yeah, i admit it's easy for me to say, i've used the 627/637 since day-1 of production and got me both APs and BPs by the dozens for $7/pc several years ago.
The line was meant as a general warning, the same thing happens with 5 cent transistors.
If someone takes the audio thing serious, and prefers not to be conned, he either buys in storage numbers or reaches for the next best Secure thing. |
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| FastEddy |
KP11520: " ... The shame here is that TI has forced many to look "Elsewhere" for the 627s in DIP. They won't be making any, from what they have said, until Spring 2008 ..."
A part of the reason for this is that the single channel '627 in the TO-99 can and its suggested PCB layout will result in better specifications (especially CMRR, noise rejection, etc.) than the 8-pin DIP physical layout will allow (there is just not enough room around the input & output to make that cute little shielding ring). Take a look at page 11 of the .PDF docs for clarification ... :eek: |
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| KP11520 |
Hi FE,
I guess that is great for new designs with even better specs, but for the modding community (especially beginner types like myself) this could be considered a disaster!
Even kits and premade PCBs for headphone amps, etc. all want the DIP package!
I guess this is where creativity has to supercede common sense! YIKES! I have to see if I can find some, somewhere (common sense that is).
Regards//Keith |
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| FastEddy |
| KP: I once took an 8-pin DIP socket and bent the leads of a TO-99 can so they plugged into the socket, then soldered the socket into the PCB ... worked fine, it just didn't look too "store bought" ... :rolleyes: |
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| KP11520 |
That's not so bad! I've seen pictures here of all kinds of rigging, so that is nothing. Pinout the same for pins 1 through 8? Since it is in a "metal can" is there any way to ground it to reduce RF affecting it (if it does or can anyway)? The "metal can" probably helps dissapate heat better too. Are the components in the "can" higher quality than the 8 pin DIP?
Thanks for showing me alternative ways!
Regards//keith |
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| FastEddy |
" ... Pinout the same for pins 1 through 8? ..."
NO!! Not necessarily, be sure you check to be sure ... (The op-amp I used was not the '627, but a much lesser variety and if memory serves the pins were difficult to get all of them bent so it would work.) :eek: |
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| eplpwr |
| Well, I bought 50 pcs OPA627AP from Effect Connection last summer (26th of June, 2007). Not until now have I've take the time to measure the chips, and this is what I get: |
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| eplpwr |
This is what a real OPA627 looks like (just like the datasheet).
BTW, I've measured 10 of the fakes with consistent results, and about 5 pcs of real OPA627AP/BP's. |
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